For centuries, the Canterlot Archives had been a fixture of the Royal Palace. Books said to be as old as Equestria itself filled shelves of enchanted mahogany, their pages lined with the script of the Old Speech.

It was here that the great philosopher Aristrotter gave his speech on the nature of life. It was here that the head of the Blueblood clan was crowned heir to the monarchy as a prize for his devotion to the arts. It was here that, according to legend, Celestia had uncovered the secrets of the Elements of Harmony hidden in a chamber containing tomes of the Old Magic.

Much of the original library had burned in the Great Fire of 243 AS (Anno Solaris). There was one building, however, left untouched by the flames. It still stood to this day, a proud yet inconspicuous monument to one of the greatest ponies that had ever lived. Within was a collection of mystical magics, arcane incantations, and universal insights that had never been surpassed, even by the most learned unicorns of the day.

With a confident grin on her face, Twilight stepped into the Star Swirl the Bearded Wing of the Canterlot Archives and let the gated doors swing shut behind her.

“The origins of time as a separate dimension can be traced back to the beginning of the universe, during which the five fundamental forces were established: gravity, electromagnetism, the strong and weak nuclear forces, and magic. As magic and causality are intertwined, the fourth dimension of time was, in essence, created to run in a manner perpendicular to the previous three. It is unknown from a theological standpoint how—”

“Twilight, must you read that at the dinner table?”

Twilight paused in the middle of the page and looked up, blinking innocently. “What’s wrong with it?”

Rarity sniffed and smoothed her mane over. “Really, dear. This is Canterlot—the center of high society!” She squealed, though muffled it under a quiet cough. A ladylike cough, Twilight corrected herself. Rarity was never one to be overt in public. “Why wouldn’t you want to take in the sights? The city is quite beautiful in the dusk.”

“And the food’s real good, too!” Rainbow Dash offered, chomping on a double-decker sandwich. “Man, I never knew they made stuff this good in fancy old Canterlot!”

Twilight rolled her eyes. “I did grow up in Canterlot, you know. I already know most of the city.”

“But can you really say that you know a city when you’ve spent half your time in it with your nose buried in a book?” Rarity raised her hooves in a half-hearted shrug. “Darling, I don’t mean to imply anything, but...”

Twilight frowned. “Hey! There’s nothing wrong with a bit of reading!”

“A bit?” Applejack snickered. “Twi, you’ve been readin’ ever since you got up yesterday mornin’.”

“So what’s that book about, anyway?” Rainbow Dash piped up. “If you’ve been reading it so much, it’s gotta be good.”

Twilight groaned. Maybe I’d be better off just staying in my room, in the castle.

“Dimensional Theoreticals,” she said, flipping to the next page. “It’s an encyclopedic collection of theories purporting to explain the origins of the four dimensions.”

Dash blinked. “Um. What?” She shook her head and laughed into one hoof. “Yeah, I’m guessing it’s probably not the next Daring Do book. You can hold onto that one.”

Twilight scowled.

“What does that mean, anyway?” Pinkie Pie asked, scrunching up her nose. “Four dimensions? I thought there were only three!”

Twilight felt a familiar rush come into her voice. This was something she knew how to do. Studying could wait another minute: there was lecturing to be done. “Well, it’s true that there are three dimensions of space—length, width, and breadth—that most ponies are familiar with. However, there’s also a fourth dimension: one of time.”

Pinkie’s mouth formed a circle. “Ooh. So wait—if we can move through the other dimensions, can we move through time, too? Like you did, Twilight!”

“A time-traveling Pinkie Pie,” Dash whispered to Applejack. She snickered. “Not something I’d ever wanna see.”

Twilight ignored her and gave Pinkie a nod. “Yup! I think that Star Swirl actually based that spell off of the research that he did into dimensional magic.” It was a shame that it had been a one-use item, tied to a unicorn’s magical signature, she thought with a frown. Think of all the studying I could have used it for!

“I read a book about time travel once,” Fluttershy piped up.

Dash gave her a skeptical look. “Really? I didn’t think you liked that science-y stuff.”

Fluttershy smiled. “Oh, but it was such a nice story. It was called The Best Night Ever, and it—”

“Oh, I simply adored that book,” Rarity put in, beaming. “The lone stallion, forced to live a single day over and over again until he is able to muster the courage to propose to his true love!” She sighed. “Such romance. I wouldn’t have thought the genre capable!”

Twilight froze. “Wait—The Best Night Ever?” She remembered reading that once when she was still a student in the Canterlot Academy of Magic. Something about the book tugged at the back of her mind: something about the resolution of the plot.

“Why, yes,” Rarity said. “The protagonist is trapped in an endless recursion until he is able to fix his life and set right what once went wrong.” She sighed again. “Wonderful.”

Set right what once went wrong! That was it! Twilight licked her lips, her gaze flickering over the cover of Dimensional Theoreticals. So far, she hadn’t found any reference to a time loop in any of her research. Oh, there had been notes on the possibility of a “backward” stream of time, but such things remained firmly in the hypothetical. Besides, time travel was a singular, nonrepeating, controlled magical phenomenon. A looped contortion in time, like some kind of temporal Moëbius strip, was just unheard of anywhere in the literature.

Anywhere, it seemed, except within popular literature.

“I remember reading that book,” she said. “I really liked it, actually.”

Dash snorted and waved her hoof in the air. “ ‘Course you did. You, not liking an egghead book? Not gonna happen.”

Twilight forced a grin to her face. “Heh. I guess.” Inside, her mind was churning, working overtime to assimilate the new information. She’d usually dismiss this kind of literary fantasy without a second thought. But this situation was so alien to her experience that drastic hypotheses were starting to look ever more attractive.

Maybe this loop of time had a purpose. She hummed to herself, running on autopilot as Applejack began talking about the catering for the wedding. She was an Element of Harmony, after all: a unicorn who had defeated both Nightmare Moon and Discord once before.

Twilight shook her head. She’d had her friends with her both times. If this was related to the Elements, why weren’t they looping as well?

Yes, but you’re the personal student of Princess Celestia herself, a sly voice whispered from the back of her mind. The sister of the Captain of the Royal Guard, and the owner of the Element of Magic.

Twilight bit her lip. That raised an interesting question. The Elements were strongly magical artifacts. Once or twice she’d suspected that they might have something approaching sentience. Would it really be beyond the impossible for such powerful objects to have created a loop in time, undoing destruction and disharmony until such a point as they could be corrected?

Disharmony such as an invasion, perhaps?

“So what’d you think of ‘em, Twi?”

Twilight blinked, her train of thought derailing. “Wha—?”

Applejack grinned at her. “I asked what you thought of the apple crumb cakes that AB sent along with us. Mighty tasty, right?”

“Oh—right.” Twilight gave a strained smile and let her calculations fade into the back of her mind. I remember this conversation. “They were really good. Red delicious apples, right?”

Applejack nodded happily. “Yup! Lemme tell ya, she was mighty proud of how those critters came out of the oven. Why, Fluttershy, did I ever tell you ‘bout the time when Apple Bloom decided she wanted to get a Cutie Mark for oven cleanin’?”

The rest of the evening proceeded exactly as Twilight remembered it, just as it had the last two times.

That night she lay in bed and looked at the stars past the fluttering curtains in her room. She squirmed as images flashed through her head of Princess Celestia, unconscious on the floor with her crown smashed into a thousand pieces.

She shook her head and tried to banish the doubts from her mind. There had to be a way. Given enough time, any problem was solvable. That was the basis of the scientific method: predict, experiment, conclude, and form a new hypothesis until a successful conclusion was reached. From this point, though, success looked a long way away.

Her dreams that night were fitful and restless.

To Twilight’s eyes, the tunnel gouged out of the wall looked like the gaping maw of a beast.

Glittering shards of sapphire littered the dusty, gravel-covered floor. Its depths seemed to stretch forever into the darkness.

From what little she could remember, her original escape from the cave system had lead the two of them—Twilight and Cadance—to an exit concealed by a well placed, oversized wardrobe. With the piece of furniture now moved aside and the tunnel laid clear for anypony to see, there was no denying it now. Her memories were as real as the ground beneath her hooves.

Twilight took a few deep breaths to steady herself. For all her arcane knowledge of time spells and magical theories, she had no ultimate explanation for this. She was almost tempted to put the wardrobe back where she had found it: to forget all about her knowledge of the future, and go back to life as usual. But she knew she couldn’t. Not even if I wanted to. I have no choice.

She exhaled and let her shoulders drop. As she stepped into the tunnel, she let the wardrobe slide back into place behind her. It slammed against the wall with a dull thud. The darkness rushed in around her, but she pushed it back using a light spell that flickered to life on the tip of her horn.

Gazing down the tunnel, she nodded to herself and began the long trek down.

The tunnel led deep under the castle, beneath the roots of the mountain upon which Canterlot was built. The ground was dusted with the shards of ancient rocks and gems. As she descended further, the scattered sapphires became more prevalent, appearing as larger and larger pieces and soon even small outcroppings growing from the walls.

Eventually she came to a crossroads. Here the crystals glittered on the ceiling and walls, giving forth enough ambient light that she could put out her own spell without sacrificing any real sight. On a whim, or perhaps a flicker of paranoia, she checked over her shoulder to see if anyone had followed her. The last thing she needed now was some curious caterer—or maybe even the imposter herself—coming down here after her.

With the tunnel behind her clear, she turned a searching eye to the caverns ahead. There were six separate branches, each leading in a different direction.

If there was one thing that Twilight could remember, though, it was a map. Closing her eyes, she summoned up a mental image of the caverns, each twist and turn outlined in her trained memory.

Her eyes snapped open, and she quickly identified the correct pathway. She took a moment, though, to place a few sapphires in an “X” pattern before the tunnel that led up to the surface. Though she was sure she could find her way out again, something about this place put her on edge.

She set off at a brisk trot and then a gallop, pointed like an arrow straight toward Cadance’s location. Whatever had happened, she had been given a second chance. She would do this. She would rescue Cadance.

And hopefully, all of Canterlot with her.

A gaping chasm proved no problem for her, a teleportation spell seeing her off to the other side. She weaved between clusters of gemstones and crystals, ignoring their glimmering shine. Running up the track of an old mining cart, she barely spared it a thought as she galloped toward her destination.

She finally came to a skidding halt before a giant formation of shimmering amethyst. Her chest heaved up and down as she eyed it up and down, recognizing it from her original memories. A few minutes spent prowling around the sides proved her suspicions: the place was airtight, sealed off more securely than a bank vault. She’d have to force her way in.

She narrowed her eyes, trying to pinpoint the most vulnerable area. As a small aura gathered on her horn, several jagged crystal stalactites floated up beside her, their sharp ends pointed toward the gemstone formation. Two bulky rocks also lifted off the ground to swirl lazily over her head.

Within a minute, she had found a weak spot: a small, concave dent in the very center of the wall.

The two boulders flew forward and impacted with a giant crash. Dust flew into the air, and debris of amethyst and sapphire flew out and out onto the ground. She took a deep breath and pulled her makeshift bludgeons back. A huge chunk of rock had been smashed from the wall, leaving a deep gouge at about eye level.

Whistling through the air, the team of crystal spears cut across the space before her and embedded themselves in the wall one by one. Needling the rock like a horde of wasps, they chipped away at the crater she’d made, clearing away dirt and cutting open the wall. Slowly but surely, they carved out a small hole that opened up into the dark interior of the crystal prison.

Twilight wiped her forehead and once more levitated one of the giant boulders above her head. After taking a moment to make sure of her aim, she sent it flying forward to crash into the wall. It sped through the air, its shadow stretching along the floor, and smashed into the exact center of the crater.

Shards of crystal flew in all directions as the rock face exploded, the floor shaking beneath her hooves. She dove to the ground and took cover behind the remaining boulders. Luckily, the barrier shielded her from the brunt of the explosion. A few bits of rock, though, slashed across the side of her face to leave thin, red cuts. The cavern shook violently for a few moments more, filled with a thick cloud of dirt.

She coughed into her shoulder as the dust fell to the ground. The debris and dirt were everywhere: in her mane, her eyes, and even her mouth. Wheezing, she managed to crack one eye open to stare into the gaping hole that she'd created in the crystalline wall. Once she’d rubbed the grit from her eyes she trotted right into it, walking through the settling dust.

“Twilight!”

Her eyes widened, and she galloped forward. “Cadance!”

“How did you find me?” Cadance rushed up and embraced her in a hug. Her coat was mattered with mud and dust, but she was beaming brighter than Twilight had ever seen her. “I didn’t think I’d ever get out of here!”

Twilight smiled back and hugged her tighter. “I’ll tell you later. Right now we need to get out of here.”

“Wait.” Cadance shook her head, looking worried. “There’s something you have to know—there’s a strange pony who’s impersonating me.”

“She’s the leader of the changelings,” Twilight said grimly. In the back of her mind, everything from her dream slid into place: the changelings were still ready to invade, Cadance had been trapped down here, Celestia was none the wiser, and Shining Armor was—

She paled. “Oh, no! Shining Armor!”

“What happened?” Cadance demanded. “Is he in danger?”

Twilight smacked her forehead. “The imposter could have his mind completely dominated by the wedding. Who knows what’s happened to him by now!”

Cadance’s eyes narrowed. “Then we’ve got to get to him. As soon as possible.”

Twilight nodded. “Let’s go. I know the way out.”

“Are you sure this is the quickest way out of here?” Cadance galloped after Twilight through the twisted caverns, weaving between crystal outcroppings as her hooves pounded on the ground.

“Almost definitely,” Twilight said. “Believe me, I don’t want to leave him alone and vulnerable any more than you do.”

Cadance nodded, evidently satisfied. “So how did you know about all this?” she asked, eyes still focused on the path ahead. “And how were you able to find me?” A drop of sweat beaded on her forehead, but she seemed to ignore it, instead pressing on by Twilight’s side.

Twilight glanced back, giving her a wary look. Should she tell her? Would she even believe me? Weighing her options, she decided to give herself a moment to think. “It’s a long story.”

Cadance gave a silent nod, and galloped on. Twilight turned around, troubled at having to conceal the truth—or at least what she believed to be the truth—from her old foalsitter. She was also relieved. Time travel was the last thing she wanted to discuss right now. Shining Armor needed their help, and every second they were away from Canterlot was another moment that the changeling had unchecked, free to do as she pleased with his mind and body.

They soon came to a stop at an intersection with several tunnels facing in all directions. Cadance stopped in place, looking around with a frown. “So where to now?”

Twilight brightened. “Aha! Right here.” She walked over to the small pile of sapphires that she’d left by the exit. “Here’s the last tunnel—we just head up, and the exit’s only a few minutes climb away.” As she looked past Cadance and back into the dark tunnels, the hairs on the back of her neck prickled. She bit her lip and pushed the sensation away. “You coming?”

Cadance nodded. “Let’s go.”

Twilight poked her head out if the tunnel and peered down the corridor. “The coast is clear,” she murmured.

“Right.” Cadance coughed as her hooves raised a small cloud of dust, but nevertheless followed her out. She watched as Twilight moved the wardrobe back into place.

“Come on,” Twilight said. “Let’s go.”

“So now what?” Cadance swallowed, trotting alongside her. She looked around with a wary eye, as though the changelings were watching their every step already.

Twilight thought for a moment. “We can’t let her see you just yet. Otherwise, she’ll know that the game is up, and she’ll either flee, or put up a fight.” She shook her head. “We need to be careful. From what I’ve seen, she might be powerful enough to take down Princess Celestia in a magical duel.”

Cadance’s eyes widened, and she paled several shades lighter. “How is that even possible?”

Twilight gave her a weak smile. “I guess Shining Armor’s love for you really is that strong. Changelings feed off of it, after all.”

“So what do we do if Auntie might not even be enough to take her on?” Cadance pursed her lips, frowning.

“Our best bet is to go get both Princess Celestia and Princess Luna together, and to try and take the imposter by surprise.” Twilight stared down the corridor, trying not to imagine it as it could have been: covered by the changelings’ greenish goop and filled with the screams and sobs of helpless ponies. “We can’t let her know what’s going on until it’s already too late.”

“Sounds like a plan.”

They walked on through the empty halls, moonlight streaming in through the windows. Suddenly, Twilight’s ears twitched, and she pulled Cadance over to a small alcove in the corridor. She held a hoof to her mouth to let her know to be quiet.

“What is it?” Cadance whispered, eyes darting from side to side.

Twilight took a deep breath. “I thought I heard voices—raised ones.” She stood there for a moment, pressed against the floral-patterned wallpaper.

“—And I told you, it wasn’t going to be a problem!”

“Dear, you’ve been so obstinate about this. I told you, I don’t want your parents poking into our private affairs!”

“But they’re my parents! What am I supposed to tell them?”

Twilight gulped, not daring to move an inch. Her ears turned to the side to catch every word spoken. She exchanged a knowing glance with Cadance; it seemed she’d recognized the voices of Shining Armor and the imposter as well. The padding of hooves on the floor was coming closer.

“You tell them this: they can either back off and let us do things the way they need to be done, or they can simply not come to the wedding.”

“What? That’s crazy!”

A door slammed shut barely ten feet from the pair’s hiding place. Twilight turned around, her mouth still sealed shut, and noticed that Cadance’s hackles were raised. The princess growled quietly and took a step forward, a fire burning in her eyes.

“What are you doing?” Twilight whispered.

“Look.” Cadance peered out into the hall, and pointed at the nearest door. A steady, green light was pulsating between the cracks, and the soft sound of pained grunting was just barely audible from their position. Her face twisted in shock and anger. “What is she doing to my husband?”

“Cadance, don’t panic,” Twilight hissed. “We just need to go to the other Princesses, and—“

“We can’t wait! What if she’s already done something irreparable to his mind?” Cadance shook her head. “There’s no time. We have to—“

“No,” Twilight bit out. “We can’t act rashly.”

“But we can’t just sit here and do nothing!”

Twilight chewed on her lip as she eyed Cadance’s worried expression. After a few seconds of thought, she sighed and bowed her head. “All right. I’ll see what I can do to hold her off.” She looked up, her eyes dangerous. “But you’re in no condition to fight. You need to run as fast as you can to the Princesses and get them back here as soon as possible. We’ve got no time to lose.”

Cadance nodded. “Got it.” With that, she took off galloping down the hall, hooves padding softly on the carpeted floor.

Twilight watched her go and steeled her will. It’s okay, Twilight. You can do this. All you have to do is hold off a super powerful creature as strong as an alicorn. She swallowed. I’ve got this.

A murmured, angry voice leaked through the crack beneath the door. “That will teach you to defy me again.”

She saw red and burst through the door.

Beyond was a large storage room with a wide-open space in the center. Boxes and crates lined the walls, the greenish glow casting eerie, flickering shadows upon their sides.

Shining Armor knelt on the ground, eyes wide and vacant. He grunted as his chest rose and fell, his breath coming in harsh, sputtering gasps. His pupils were dilated, the veins in bloodshot his eyes clearly apparent. Above him stood the imposter. A beam of jagged green light ran from the tip of her horn into his as if blazing a path straight into his mind.

In that moment, Twilight forgot everything about strategy, tact, or discretion. All that mattered was that her big brother was hurting and that she was going to make it stop.

As Twilight ran into the room, the imposter turned with wide eyes, her mouth hanging open. “Who—?”

Twilight threw a crate at her.

The imposter went down hard, sprawling across the room. A quick spell sent several other barrels and sacks tumbling down onto her fallen form. Twilight growled and steadied herself on the wooden floor.

A soft, green glow surrounded the crates, and with a bang, they all sped away from her to crash into the walls. Twilight narrowed her eyes and summoned a purple shield to protect herself. The barrels and other objects bounced off of it and passed harmlessly to the side.

“Twilight?” the imposter said, her voice sounding softer and more innocent. “What are you doing? Why are you attacking me like this?”

Twilight snorted, eyeing her with disgust. Is she really stupid enough to think that will work? “The game is up, changeling. You’re going to lose.”

The imposter sighed and rolled her eyes. “Ah, well. It was worth a try.” Her eyes narrowed, and the door swung shut behind Twilight, several crates and barrels levitating up in place to block her exit. In a second, her face transformed into its natural terrifying visage. She snarled. “You, my little pony, are not going to get off easily for this.”

“Try me.” Twilight prowled around the edges of the room, the changeling mirroring her movements. Her horn buzzed with magical energy, and her step betrayed a tension that suffused the room.

The changeling was the first to make a move. A bolt of green energy crackled through the air toward her, sending her tumbling to one side to dodge it. Twilight felt magic building before she had even consciously focused it and retaliated with a purple bolt of her own. The changeling blocked it with a sack of flour.

The changeling growled and shook a cloud of flour from her mane. “You can’t run forever.”

“Neither can you,” Twilight shot back, a new spell crackling on her horn. She felt the power building up at the back of her skull, pounding behind her eyes, and released it. Dozens of tiny, magical “stings” shot from her horn, each one no more powerful than a small dart, but more than enough together to knock a pony out cold.

A team of emerald bolts met Twilight’s in mid-flight, dissipating them harmlessly into the air with a loud zap. The changeling’s lip curled, and she sneered. “Your attempts at offense are pathetic.”

“And yours aren’t?” Twilight frowned, calculating. She couldn’t let this come to a direct confrontation: this was the same creature that had been able to defeat Princess Celestia, after all. The changeling was playing with her, testing her defenses. Her best bet was to keep the changeling underestimating her, and then to strike her hard and fast when she least expected it.

She felt the variables and numbers coming together in the back of her mind. She needed to stall, and the best way to do that would be to incapacitate the imposter before she even knew what had happened. Her mind working like lightning, she began to piece together the components of four separate spells in the back of her thoughts.

The first spell matrix finished. It wove itself into a telekinetic net that picked up another team of wooden crates, leaving them hovering in the air threateningly.

The changeling threw back her head and laughed. “You’re trying that again? Foolish unicorn.”

Sweat beaded on Twilight’s brow; she dared not speak for fear of losing her concentration. Instead, she focused on the spell currently in her hooves and sent the projectiles flying toward the changeling in a whirlwind of wood and debris.

Sneering, the changeling let her own horn light up, a green glow building up brighter and brighter at the tip. “Perhaps it’s time to stop playing around. No one defies Queen Chrysalis.”

With a roar, a beam of burning, viridian fire burst from her jagged mockery of a horn. It smashed into the crates and ripped them into charred pieces. It sped forward, the air sizzling around it as the spell gathered a blast of concussive force—

The second spell matrix clicked into place, and Twilight’s form rippled and disappeared.

“What?”

The imposter looked around in confusion, wide-eyed. There was no unconscious body, lying scorched on the ground. There was no upstart unicorn, whimpering in pain at her hooves. Instead, the other pony had vanished before her eyes.

With tremendous force, Twilight reached out with her mind and pushed.

The telekinetic barrage sent the changeling flying across the room. Her torso was pummeled from behind with invisible blows, the sheer volume of spells flinging her off of the ground and into the air. Her whirling body broke down the door and part of the wall, crashing onto the ground beyond.

Still recovering from her teleportation spell, Twilight took an unsteady step forward as the imposter tumbled onto the ground in a jumbled heap. The changeling groaned, shifting on the ground. Twilight knew it was her only chance. She released her fourth and final spell.

The crackling beam of cold blue whistled through the air and smashed the changeling right in the chest.

Almost instantly, a wave of crystalline ice washed over her body from the point of impact, forming a hard, glimmering shell that froze her in place. The changeling struggled, but it was futile. The ice soon covered her limbs and face, leaving her frozen with an expression of horror and agony.

Twilight wheezed, her chest rising and falling as her heart beat like a drum. There was a steady throb beginning to thump in her head: no doubt a consequence of forcing herself to cast so many spells at one time. She shook her head. But it had been necessary. And for all intents and purposes, it had worked.

She swallowed, putting a hoof to her head as she walked forward to admire her handiwork. The changeling’s body gleamed and shimmered like diamond, the dim light of the torch-covered walls reflecting off of the surface of her skin.

I’ve done it. She’d incapacitated the imposter, and Cadance would be arriving any minute with the other two Princesses. Equestria was saved.

Something flickered in the changeling’s eyes.

Before she had the chance to react, a wave of green light burst forth from the imprisoned changeling. It vaporized the icy shell around her and sent Twilight flying back toward the wall.  She fell in a crumpled heap on the ground and moaned. Her ribs burned like they were on fire.

The changeling moved forward with a wildfire dancing in her eyes. Her chest heaved up and down as sweat dripped down her face. “Oh, you’re good. Too good, even.” She licked her lips. “I don’t think I can allow that.” A circle of green flames sprang up around Twilight’s hooves, flickering in the shadows.

Twilight groaned, struggling to get up. “It…won’t work,” she panted as she stared up at the changeling defiantly. “I’ve already released Cadance from her prison. Princess Celestia and…Luna are already on the way.”

The fire in the changeling’s eyes flared up monstrously. “What?”

Twilight smirked, though she found herself struggling not to betray her real emotions. Much as she might have liked to beg, plead, or even grovel, she refused to give this creature even the slightest bit of satisfaction. “Face it, Queen Chrysalis. You’ve lost. Your cover is blown, and soon all of Equestria will be safe from you!” She winced at the sound of a low scraping noise before realizing that it was the changeling grinding her teeth.

“You… You dare?” Chrysalis demanded, her voice strangled and twisted. “You have destroyed my plans, forced me to use my stolen power before ready, and even—” Her face contorted into an ugly snarl. “You will die for this.”

Twilight swallowed. She would not let this monster taste her fear. She would wear a face of bravery to the end. “Give me your best shot,” she spat and braced herself for the end.

Outside, she heard the sound of rising shouts and the galloping of hooves. She squeezed her eyes shut and prayed. Oh, please let them make it in time—

Chrysalis seemed not to hear the approaching force. If she did, she gave no sign, twisted up in rage as she seemed to be. She spoke three words.

“Die, Twilight Sparkle.”

A beam of white-hot, emerald fire burst forth from her horn, crackling through the air as the smell of ozone filled the room. The light was so fierce as to be almost tangible. The flames flickered like demonic faces, rushing straight toward Twilight’s defenseless body.

She gave Shining Armor a helpless look as he stared back at her with empty eyes. Shining…I’m sorry.

And then all she saw was fire.

Ripples.

A beam of light struck the surface and shattered into an array of dazzling colors.

Twilight took a deep breath as she stared into the water. Her reflection glared back at her and she flinched, reflexively raising a hoof to her mane. Though they’d long since disappeared, she could still feel the burns that had covered her skin. Both times before, she'd been unconscious when the loop ended. This time, though...

Her breath caught in her throat and, for a second, the image in the pool wavered. Her mane became a lump of char and tattered grey, her lavender coat replaced with an ashen, bleeding mess of—

She shook her head and took another breath to steel her nerves. She forced herself to look her reflection in the eye.

This death had been...unpleasant.

She swallowed and turned away from the pool. Around her, bluebirds chirped from the trees. A warm breeze whispered through the flower bushes that crowded the Palace Garden.

She lacked firepower. That was the simple part. If she had been able to hold out for even a minute or two more, than perhaps Celestia would have made it in time. Maybe Chrysalis would have been stopped. Maybe Shining Armor would be safe.

Twilight scowled and flicked her tail behind her, kicking up a small cloud of dust. Maybe, maybe, maybe.

There was one problem, though, that towered above the rest. She looked up at the sun and flinched back, the bright color burning her eyes. Could she trust herself to go through that again? To risk herself, even if she had assurance that she'd be—in a fashion—resurrected at the end? To imagine the flames, licking at her hooves and burning her flesh?

Her jaw clenched. She'd have to.

It was her only chance.

Getting Cadance out of the caves proved once again to be fairly easy. Chrysalis hadn’t yet bothered to place guards around the entrance—which was admittedly well-hidden—and Cadance had been a bit easier to direct when Twilight pointed out that Shining Armor wasn’t in any immediate danger. It was true, this time at least: Twilight hadn’t set her plan into action until the loops restarted, giving her the maximum possible time to make sure things went her way.

Clearing her throat, she raised a hoof to knock on the door to Celestia’s chambers.

“Princess? Princess Celestia, are you there?”

“Twilight? Is that you?” Her rainbow mane preceding her, Celestia poked her head out of the door and into the hallway. “Ah, Twilight! Cadance! How have you been? Is there something I can help you with?”

The two exchanged glances. “You might say that,” Cadance said.

“So there is an imposter in the Palace.”

Celestia’s voice was calm but echoed in the stillness of the room. Twilight had rarely seen it before, but her mentor’s ire had peaked once or twice in her time as Celestia’s student and it was clearly being kept in restraint now.

Cadance nodded. “Yes, Princess. And not only that, but she’s trying to harm Shining Armor’s mind.”

“I see.”

Celestia’s expression was unreadable, but when she stood up there was a sharp edge to her voice. “You did the right thing in coming to me immediately. If what you say about the…power of this imposter is true, Twilight—,“ she offered a curt nod, “—then I will need my sister’s help to defeat her.”

“I don’t know if she’s managed to take enough of his love to become a real threat yet, but it can’t hurt to be safe,” Twilight said.

“Very well.” Celestia took a deep breath.

“And what about me?” Cadance asked. Twilight noted, with some surprise, that most signs of her imprisonment had disappeared. The remaining debris in her mane, though dusty and grey, did nothing to diminish the determined gleam in her eye. “I want to help.”

Celestia gave her a worried frown. “Are you sure? From what you’ve told me, you’ve been imprisoned for at least a week, with barely any food or water.”

“I’m sure,” Cadance said. “I won’t let that monster touch me or my husband ever again.”

“Very well, then.” Celestia smiled. “I will send one of my Guard to wake Luna from her sleep. She will understand.”

“And then?”

She turned to Twilight with a steely look in her eye. “And then, my little ponies, we will defend Equestria.”

It had been, Chrysalis reflected, a very good day.

She smiled from her place atop the soft bed of her Face’s quarters. She had taken many Faces in her time, but this was the first that had come with such…lush conditions.

She smirked. The ponies were soft—miraculously so, even—but that didn’t change the fact that their magic was strong. Luckily, the leader of their forces was proving more susceptible to her touch than she’d dared hope. She could occasionally feel something beneath the surface, still resisting her, but there had been no changeling in all of history as skilled in manipulation as she. He would surrender as all the rest had. Even now, from the other side of the castle, she could feel his mind yearning to reach out and feel her touch once more. He did need the occasional touch-up, but really, it was little fuss.

With her great army already in position outside of Canterlot and ready to strike at a moment’s notice, the Queen of the Changelings had never felt better.

This wedding is going to be perfect.

There came a knock at the door.

Chrysalis felt the innocence of her Face slide over her own features like melting butter. “Yes?” she asked, making sure to affect just the right amount of naiveté. Inside, she tsked softly. These ponies could never hope to recognize a good actress when they saw one.

Undoubtedly, it was a member of her “fiancé’s” Royal Guard, come to check up on her. They were always so cautious around their precious princess, the poor dears. Really: their devotion, although severely misplaced, was almost admirable.

“Princess Cadance?”

She recognized Celestia’s voice with more than a twinge of annoyance. What could the blasted Princess need that she wanted to speak with the bride, anyway? Her Face was Celestia’s niece, but surely the ruler of Equestria had more to attend to. Besides, hadn’t these idiots ever heard of privacy?

She let none of that irritation show on her face, of course. To the world, she was Cadance, the young and emotional princess of Canterlot Castle. Her disguise was perfect; there was nothing to worry about.

“Come in!” she sang out. Inside, though, she seethed. The sooner she could get Celestia away, the better.

The doors swung open, and Chrysalis froze.

Outside of the foyer stood Princess Celestia, her face a hard, stern mockery of her normally regal expression. Princess Luna stood there as well, something dark glittering in her black eyes. Beside them was a lavender unicorn; Chrysalis felt a bit of annoyance that she hadn’t done more research on the Princess’s apprentice yet. What was her name again: Dusk? Shimmer?

What she saw next, though, made her heart stop in place.

From the doorway, her current Face glared back at her.

“I believe there is no need to explain why we are here,” Celestia said quietly.

Calculations began to race through Chrysalis’s mind, and she grit her teeth. That was it; the game was up. Somehow, impossibly, they had found the real princess and now dared to confront her.

“Thou art under arrest for thy crimes against Equestria, changeling.” Luna scowled down at her. “Come quietly, or we will be forced to take more direct measures.”

“It’s over, Chrysalis,” snarled the apprentice—Twilight Sparkle, she remembered. Idly, Chrysalis wondered how she knew her name. Not a breath of her existence had been allowed outside of the Hive for more than one hundred years. To the world, the changeling race was but a disorganized mass of scavengers. “Give up. Soon, Shining Armor will be back to normal, and this whole invasion will be one big failure.”

With a sigh, Chrysalis let her grip on her Face fade. She might have enjoyed the ponies' looks of revulsion had she not been busy trying to keep herself calm. “A pity. I did so enjoy my little games.”

“Little games?” Cadance asked. There was something dangerous behind those eyes, Chrysalis noted: a burning fire that she hadn’t accounted for. For a moment, she wondered if the so-called Princess of Love had escaped on her own, but no, that was impossible. “You enslaved my husband with your mind control.”

“Thou hast plotted against Canterlot, and against Equestria itself,” Luna thundered. “Thy crimes speak for themselves.”

“Ah, but I got quite close, did I not?” Chrysalis smiled sweetly up at Celestia, letting her features ripple until they resembled those of the Princess’s student, staring into her eyes with mock adoration. “Tell me, dear teacher; did I do well?” She nearly laughed at the momentary rage that flashed across the princess’s face. Such emotional control. Tsk, tsk, princess. In the back of her mind, she began to reach out with her thoughts, probing for the flickering conduit that connected her to the rest of the Hive.

Celestia scowled. “I never thought the changelings to be as brazen as this.”

“Oh, come now, dear Celestia,” she purred. “All of the power of Canterlot, concentrated in a mind as weak as this?” Her form rippled and changed until it became that of Shining Armor. She gave a mock salute, her voice dripping with sarcasm. “Emotional investment is never a good idea for a military stallion. Things tend to get…”

She smiled, letting one undisguised fang poke through the illusion. “…Messy.”

Inside, she was panicking. She loved her mind games, but the simple fact that she was outnumbered and very much outmatched meant that there was little hope for her own survival. With a sudden rush of triumph she felt her mental link connect, breaking through the barrier around the city. A familiar feeling of warmth washed through the telepathic connection.

Our queen!

Chrysalis sighed deeply, smiling as she felt the voices of the Chorus echo in her mind. She realized that she rather liked the surprise with which the ponies reacted to her relief. Overestimation could sometimes be a more powerful tool than its opposite.

I have been discovered.

She waited a moment for the shock to fade before speaking through her connection to the Hive once more.

I do not know how: only that I have been betrayed. Whether by myself or by another, I do not know. But there is no escape available to me, not now.

She let her Face fade and resumed her original form.

“By all means, dear Celestia; Luna; Cadance.” She gave the last name a little quirk: a small twist in the inflection, and was delighted when she saw the Princess of Love wince. Oh, yes. She remembered the “long talks” of their first few nights quite well. A pity she had to stop once her security detail began to watch her more closely. “Take me into custody. I shan’t resist.”

A wail went up through the telepathic link. We shall save you, Your Majesty!

Do not, she warned. Their magics are still strong, and my cause is lost. There is no hope for me now, not through blunt force.

“Really,” Cadance said flatly. If looks could kill, Chrysalis reflected, she would have been crushed beneath a mountain of pure hatred by now.

“Really,” she echoed. She put a hoof to her forehead and added a melodramatic flair to her voice. “I know when I am outmatched. Truly, you have won this day. I shall not oppose your efforts.” She sighed. “The two Princesses of Night and Day? The daughters of the Eternal Queen? What chance have I—a mere misshapen wretch—before such power?”

They lapped it up, of course. The caution was there but their stances were more relaxed, less hostile. As the two Princesses stepped forward, she turned all of her will to bear on the Hive. She had little time.

Then what will we do?

You will flee, she sent, feeling a tinge of worry for her subjects. You cannot hope to invade Canterlot now.

Take instead the other pony cities. They have few defenses and are ripe for feasting. Equestria must rue the day that Queen Chrysalis fell.

The mass of sentience within her mind was shifting; fear was fading, to be replaced with concern. And what of you, our Queen?

I will stay. Chrysalis eyed the guards entering the room with some disdain; admittedly, it came off as more of a squint due to the hazy magical field that had sprung up around her, sealing off her power. They will not kill me. They are too weak for that. Perhaps one day, I shall escape from their dungeons. Time is of no concern.

The telepathic touch of the Hive began to wane in strength, but the warmth of that connection still lingered. We will not forget you, our queen.

Chrysalis smiled sadly.

Thank you.

Twilight watched the door to the Canterlot Castle’s dungeon slide shut, the portcullis falling to the floor with a crash. She closed her eyes as a wave of relief washed over her.

“So that’s it, then.” Cadance stood up straighter.  “She’s done.”

“It would appear so, dear niece,” Luna said. She reached forward hesitantly before placing a hoof around Cadance’s shoulder. “Canterlot is now safe from the changeling menace.”

Twilight frowned, a stray thought tugging at the back of her mind. “I did expect her to put up more of a fight,” she murmured.

“What would she have done?” Luna raised an eyebrow. “She was outnumbered and overpowered. Her task of secrecy had failed.”

“I guess.” Twilight brushed the ground with a hoof, her tail swishing in the air behind her. “Still, I just wonder if—“

“The shield is safe.” Celestia walked into the room with her head held high. “I’ve seen to it that Shining Armor receive the best care for his condition, but it seemed prudent to leave the protection bubble in place for the moment. I’ve just finished reassuring the nobility; they seem to think that the city was already being invaded.” She sighed, shaking her head. “I swear, this will be a nightmare to deal with in the weeks to come. The paperwork itself for the extra security detail will be…unpleasant.”

“Worry not, sister,” Luna offered. “Tis a small price to pay for the safety of Canterlot against this changeling army.”

Twilight felt her heart freeze in her chest.

Wait.

“If we had not had your warning, Twilight, Canterlot may well have fallen.” Luna beamed at her. “For that, you have my thanks.”

Twilight’s throat constricted. “Princess Luna,” she croaked, barely trusting herself to say the words. “You said something about the changeling army?”

“Why, yes.” Luna put a hoof to her chin. “You did mention it when I was summoned to my sister’s chambers.”

A quick glance to Celestia’s features told Twilight that their thoughts were on the same track. “But we only captured the leader—their Queen.”

“And?” Cadance gave her a frown.

“Yet the army is still at large.” Celestia’s voice was quiet, but filled with a similar apprehension.

Twilight began to pace, her hoofsteps echoing in the empty hallway. “We focused on the leader: the corruption already in Canterlot. We took care of the head, but—“

“What then happens to the body?” Luna’s eyes widened. “Oh, dear.”

“They came to Canterlot for conquest,” Twilight murmured. She shook her head, her mane falling down haphazardly over her ears. “But the changelings themselves only desire food: love, as well as territory. There’s no reason they would only be able to come here to get it.”

“So we have a horde of changelings,” Cadance murmured, “freed from any semblance of organization or leadership, running amok over Equestria.”

There was a great crash at the other end of the corridor.

“Princess Celestia!”

Celestia’s head whirled to the side. “Captain Thunderfoot!”

The pegasus guard slowed to a halt, his armor clanking loudly. His chest heaved, and a thin sheen of sweat covered his face. “Princess, terrible news.”

“Speak.”

“We’ve just received reports from routine flyovers of Manehattan and Fillydelphia. Both have been swarmed by an unknown attacker.” His eyes were dark and worried. “Our scouts say that the cities are barely holding up, especially after much of their own security was removed to protect Canterlot. We’ve dispatched several squads, but their numbers may not be enough to protect the cities entirely.”

He knelt to the floor. “They cannot hold on for much longer.”

Twilight felt sick.

“Escort me to the War Chamber immediately.” Celestia’s voice sounded hollow, empty of any real emotion. When she spoke again, though, slivers of rage undercut her tone. “We will protect Equestria.”

“Manehattan is burning.”

From her place behind her, Twilight watched Celestia wince as if physically struck

“Princess, the squads have arrived at Fillydelphia and are holding in the Central Office.”

“Reports coming in from Los Pegasus—some sort of skirmish going on over there.”

From the bustle of the War Chamber, her haunted gaze stared out of the window and looked over the Canterlot skyline.

“I can still protect them,” she whispered, watching the sunset in the distance. “I should be there.”

Luna put a hoof on her shoulder. “Yet how much can you truly do? Sister, there is no single enemy to combat.” Her voice was heavy with regret. “Tia, there is no Nightmare or Discord to fight here.”

Celestia’s jaw trembled, her mane blending with shades of deep red and gold. “No. I will not allow my little ponies to fall without me.” She looked up, and a harsh regality returned to her voice. “I will protect my subjects.”

“Princess, I’ve finished organizing the Sixth through Tenth Pegasi Squadrons,” Captain Thunderfoot said with a salute. “We’ll be sending along our experimental team of teleportation-oriented unicorns; their magic, at least, should be useful in putting out the fires.”

“Good.” With a nod, Celestia moved toward the great window that opened up to the Canterlot skyline and spread her wings. She paused, stopping in place. “Twilight Sparkle.”

Twilight slowly turned to face her mentor as dread dripped down her spine. “Yes, Princess?”

Celestia looked back, her face twisted in grief and agony. “I am sorry.”

She leapt from the balcony, riding the winds toward the dark splotch on the horizon that was the city of Manehattan. As Twilight watched, her form faded into the distance and seemed to merge with the setting sun.

Luna stepped forward. “I will remain to govern in my sister’s absence.” Her eyes glinted like polished steel. “Captain! I want a full status report of Canterlot’s military strength within five minutes.”

“Yes, Princess!”

Twilight watched the chaos around her with horror. Canterlot was saved, but at what cost?

This…

This wasn’t how it was supposed to happen.

With the voices of the Guard echoing in her ears, and smoke and fire filling her thoughts, she turned and walked away.

The dim light flickered, shadows dancing across the walls. The soft smell of melting wax filled the room. The only sound was that of a quill, scratching across parchment.

With a groan, Twilight crumpled up another piece of paper and flung it away to join a growing pile of trash.

She’d been wrong. Even worse, she’d overlooked a crucial variable. Chrysalis was dangerous, to be sure, but the Queen hadn’t taken the city the first time. Her army had. Twilight sighed and rubbed her eyes. It was likely that she'd felt a stronger emotional response to Celestia’s defeat and unconsciously made preventing it her only priority, but that was no excuse. She’d failed.

Again.

Taking a deep breath, she pushed herself from her seat and turned to the bookshelves lining the entrance to the Study Room she’d settled in. The Archives were filled with these rooms: they were quiet, peaceful, and good for thinking. Her eyes roamed across the shelves, but her thoughts were somewhere else entirely, swirling madly as she searched for a plan.

The changeling army had an overwhelming number of advantages in this fight, she realized. Not only did the Guard have to worry about both their own safety and any collateral damage, but each changeling, by all anatomical observations, was a miniature alicorn: horned, winged, and built for speed and power. Pegasi had no defense from their energy blasts and many unicorns were unable to hit an airborne target. It was the Equestrian Army’s worst nightmare—and, she noted with dawning horror, why Shining’s barrier spell had been so revolutionary in Canterlot’s protection. In this case, prevention was the best defense.

It was becoming apparent, though, that walling themselves off and hoping the problem would go away just wasn’t going to work. The changeling horde was an active and dangerous force, and needed to be taken care of.

So there it is, she thought glumly. The “to-do list” of saving Canterlot. Taking Chrysalis prisoner was easy enough, but she needed some way to shut down the army as well. The Canterlot Guard would be vital in doing so, but from what she’d seen, there’d need to be some sort of magical advantage on the Equestrians’ side.

A magical advantage...

She smacked her forehead.

Of course! How could she have been so stupid? Equestria had all of the magical firepower it needed, and it had been right beneath her nose the entire time! Heck, the first time she died had been in pursuit of that very thing!

She smiled, a shade of glee in her eyes. The first time, Canterlot hadn't been ready. She hadn't been ready. But this time...

This time, the Elements of Harmony would protect Equestria once more.

It was pretty lucky, Twilight reflected, that Chrysalis had gotten arrogant enough to gloat about her evil plans to her prisoner. In any other circumstance, that'd be useless; after all, Cadance had originally been locked up for so long that by the time she’d been rescued, it was already too late. But this time, it'd be different. Thankfully, she could pass Cadance off as an informant in order to avoid any awkward questions from the other Princesses about knowledge of the future. It was easier this way.

"We're here," she breathed as they reached Celestia's throne room. She glanced around warily. It was still early enough in the morning, though, that they were almost guaranteed their privacy.

"Good." Cadance shook her mane out of her eyes and reached up to shove open the doors. Twilight blinked at the anger that cut through her voice. "It's time to save my husband."

"Save him from what?"

"Princess Celestia!"

Celestia sat upon her throne, her crown glittering in the morning light. Twilight noticed, somewhat awkwardly, that the Princess was halfway through a yawn. There were circles under her eyes, and a coffee mug hovered at her side. She felt a strange pang of nostalgia in her chest. In all of her time since leaving Celestia's side, she had somehow forgotten that, godly power or no, even the Princess needed a little something extra to knock off the sleepiness in the morning.

“And a good morning to you as well.” Celestia smiled pleasantly and gestured for the two of them to approach.

Cadance slammed the doors shut behind them. "We need your help."

"With what?"

Twilight’s heard whirled to the side, and her eyes landed on a deep blue mane. “Princess Luna! You’re here, too?”                                                                                                                                                                                                                                                                                                                                                                                     

"Indeed, Twilight Sparkle." Luna inclined her head in greeting before trotting to Celestia's side. "I was just about to leave for my quarters, having finished Moonset and left the throne to my sister.”

"Right,” Twilight said.

"So what is this problem?” Celestia asked. She frowned, her eyebrows furrowed. "Does it have anything to do with the fact that my niece looks like she's recently fallen into a hole?"

"Princess Celestia." Cadance stepped forward, the sound of her hooves echoing on the marble floor. "For the past week, until Twilight rescued me, I was being held prisoner beneath the castle."

Celestia's eyes widened at the same moment that Luna's narrowed with suspicion. "What do you mean?" Luna demanded. "I observed you with Captain Armor only last night!"

"That's an imposter." Twilight shook her head. "This is the real Cadance."

Luna's eyes widened to the size of Celestia's, and her voice became a quiet murmur. "Explain yourself, niece."

"It's true." Cadance's voice was steeled with determination. "There's a creature in the castle who looks like me. She imprisoned me in the system of caves beneath the castle, and she's trying to take over Shining's mind in order to bring down the barrier shield.”

"She's called a changeling," Twilight said. Celestia inhaled sharply. "She's the one that made the threat against the city, and if she's able to get through to my brother, then the barrier won't stop her."

"Stop her from what?" Luna asked.

"Invading the city with an army of changelings."

Celestia turned to Cadance, her eyes flashing. "Are you sure?"

"Yes," Cadance said. "This...changeling took great pleasure in taunting me when I was her prisoner." She swallowed, and her voice wavered. Twilight put a hoof on her shoulder; Cadance gave her a weak smile and went on. "She gloated about her evil plans, ranting about how she would destroy Canterlot from within and then crush it until there was nothing left."

“From what the changeling told her,” Twilight added, “their army numbers in the thousands, or even tens of thousands.”

"Thousands," Celestia breathed, her pupils dilated. She exchanged a look with Luna, who nodded solemnly in return. "There hasn't been a militarized force of such size since—"

"Indeed." Luna stepped forward, her tiara glinting in the morning light. "What would you propose we do then, Twilight Sparkle, to defend Canterlot from this threat?"

"I think you already know the answer, Princess." Twilight turned to face Celestia with a fire burning in her chest. This was it. This was where she fixed the mistakes she’d made the first time around. "After all, my friends and I are more than familiar with the tools in question.” She watched her teacher’s eyes intently, waiting for the spark of realization to appear. Celestia didn’t disappoint her.

"The Elements of Harmony," she murmured. "Yes; that might work. They have dealt with similar threats against Equestria before."

"As with the Empire?" Luna offered. Celestia nodded, and Twilight noted down the word "Empire" for later study. She'd never heard of such a thing in all her studies of Equestrian history.

"Yet the Elements may only be used in the face of clear and present danger." Twilight thought she saw a flicker of shame in Luna’s eyes.

"Wait," Cadance said. Realization dawned on her face, and she glanced over at Twilight. "That means we'd only be able to use the Elements if the changelings were already invading."

Celestia cleared her throat. "The Elements of Harmony have always been, as their name suggests, a power for defense, and not a weapon. They maintain balance; they do not seek it out of their own accord."

"So, yes," Cadance said glumly.

"And there's still the problem of the leader, right?" Twilight leaned over and gave her a nudge.

Cadance nodded, her mane bobbing up and down. "Yes. I didn't believe her at first, but somehow, she's been able to steal away Shining Armor's love for me, and use it as a way to power and feed her own magic." She shivered, and Twilight recalled the burning, lustful glare in the changeling's eyes that had stared into her brother's face. "She said that she might even be stronger than you, Aunt Celestia."

Luna recoiled backwards as if slapped, her mane flaring up in agitation. "What? That's impossible!"

"Not necessarily," Twilight said grimly. "Changelings seem to feed off of love as both sustenance and a power source, and if Shining's love for Cadance really is that strong, then there's no doubt that given enough time, this imposter might be able to amass enough strength to overpower even an alicorn."

Luna and Celestia exchanged a glance. "I very much doubt that to be true," Celestia said slowly. "However, the circumstances under which I would be forced to use my full power would be...uncomfortable for the rest of Equestria."

"The ground would be reduced to a barren wasteland of smoldering cinders," Luna muttered. "Such is the power of the Sun—hardly a tame or subtle creature."

"That's enough, Luna." Celestia let out a long sigh. "It's certainly possible that I would be overpowered, should I be forced to limit myself for the safety of my subjects."

"Then we must both confront her." Luna slammed a hoof onto the ground with a snarl.

"But she needs to summon the invasion first," Cadance pointed out. "Otherwise, the changeling army won't be close enough for the Elements to work, and they'll be free to spread out over the rest of Equestria."

Celestia sighed again and gazed into Twilight's eyes. Twilight suddenly felt as though she was being evaluated by a dragon or ancient creature, unable to look away. She'd rarely glimpsed the full weight of years that hid behind the Princess's face. It was as if a mask had been shifted aside to let a sliver of the truth peek through, carrying an unfathomable and powerful wisdom in its stare. She shivered.

After a moment, Celestia spoke.

"Well?"

The silence was broken, and time began to move once more.

Twilight nodded, the adrenaline already rushing into her veins. "I've got a plan, Princess. Here's what we have to do.”

The changeling had no name.

He—not she, never she—had been born into the dark tunnels of the catacombs. He had chewed through the tough hide of the beast that had incubated his brood, bursting into the green, glowing shadows that marked the tunnels of the Hive's nesting grounds.

His Queen had been there, though he had not known it at the time. It was only hours later when he was first introduced to the Hive that he learned that she had been watching over him and his brothers as she did every group of young. She had watched as the horde of larvae tore their way out of the cow whose body had carried them for forty days, and welcomed them into the Hive with open hooves.

And then he had known no more. His life with his Queen's: his food, his hole, and his life were hers. His was an extension of her will, and so he carried it out for all his life.

The changeling had no name.

Their Queen called, and the Hive awoke.

Their eyes opened as one, legs drifting through the green gelatin that protected their nests and nourished their young. Slowly, they reached out of the thousands of holes dotting the caverns beneath the mountain that they now inhabited. Their exoskeletons shimmered in the dim light of the crystals growing in the tunnels.

Their Queen was calling them. She, finally, had need of their service. The Hive gave a rallying cry: a call to battle. They had been brought from the Outer Lands to this place of bounty at her command. Now, it was time to become the hammer that would shatter their prey against the Queen's everlasting might. One by one, the caves filled with a terrible, angry buzzing.

By the hundreds, and soon thousands, the changelings erupted from the dozens of entrances that hid beneath the roots of the mountain. They curled up beneath the glimmering city and waited for their Queen to give the signal. Through the link came a sense of cool confidence that soon pervaded the Hive. They watched the huge sphere that protected the city—their food and bounty—with hungry eyes. The Hive would wait. It would hunger—it had always hungered, and always would—but for now, at their Queen's behest, they would wait.

The changelings knew it not, but the sound that echoed through their heads, filtered through the telepathic link, was organ music.

With a triumphant cry, a single word rang out through the Hive, and the changelings obeyed.

Come!

They crashed upon the offensive sphere and cracked it into a million, glittering pieces. With a buzzing that filled the skies, they rushed into the city to seize their prey. Their Queen had delivered this bounty unto them, and the Hive was grateful. Below, the screams of ponies were already beginning to spread throughout the city. A wicked grin spread across each changeling’s face: it was time to conquer. It was time to feed.

And then, with a single scream, the Hive fractured.

Images flashed across the compound eyes of one changeling as he fell through the sky. He understood them not, but they were visions of his Queen, and so he watched in silence and awe. He saw an angry goddess: a creature born of heat and light and life. Another joined her, and his Queen shied back in agony, for just as the first shone with the light of the Sun, so did this one burn with the soul of the Moon.

And then there was pain.

The changeling stopped, feeling confusion, anger, and then confusion again—and then the link, for the first time in his life, was cut. The Hive was alone.

Canterlot erupted into an explosion of a thousand discordant shrieks. The Hive had not been untamed since before the days of the Queen, centuries before. They had come from beasts, and to beasts they would return. But just as the great cloud of black in the sky began to disperse, the first changeling saw something else.

A small group of ponies, clad in shining garb and metal, stood on the tallest point of the castle. They shouted a single word to the boiling skies.

"Now!"

With a deep hum and an explosion of color, a stream of light burst forth, swirling and dancing. The light—the horrible, terrible light—coalesced into a single sphere and began to expand, growing until it held the entire tower within its whirling depths.

And then it exploded outward with unimaginable force.

The changeling snarled, its snout contorting and its legs writhing in agony. It had not known pain before. This was pain, truer than any it had ever endured. It felt its form crushed beneath the ever-watching light—that huge, blinding brilliance—and cried out as it was judged unworthy and collected into a growing pile of its brethren. It tried to scream again and found it could not; its mouth was held shut and its wings frozen in place, powerless to escape.

And then, with a giant push, it found itself flying away at a great speed. The light was disappearing, its wings were returning, and the shining castle was vanishing into a speck in the distance—

The changeling hit the ground with a thud and knew no more.

Twilight watched the changelings disappear over the horizon with her heart in her throat. For a second, she'd been worried that it hadn’t worked. Now, as she saw the remnants of the invasion soaring into the distance, all doubt had been banished from her mind. The changelings were gone, and Canterlot was safe once more. They had won.

We’ve won.

Her chest heaved up and down, a trail of sweat running down her brow. Without really thinking about it, she raised a hoof to wipe it away. She shouldn't have been this tired out from using the Elements of Harmony, but she paid the thought no mind. Glancing around, she noticed the others around her: Pinkie Pie, bouncing up and down in glee; Rarity, standing still with a small, unassuming smile; and Rainbow Dash, looking a bit fatigued as well, but exchanging a grin and a hoof-bump with Applejack beside her.

"Oh, my," Fluttershy murmured. She looked up at the clear sky. "I hope they're all okay."

"Okay?" Rainbow Dash spun around and shot her a suspicious glare. "If they'd gotten the chance, they would've destroyed Canterlot! Just ask Twi!"

"It is indeed quite fortuitous that you managed to uncover this plot, dear." Rarity offered her a wink and trotted up to her side, giving her mane a quick nuzzle. Twilight's cheeks turned red. "If you had not, then where would we be?"

Applejack snorted. "Beneath ten feet of black monster beasties." She clapped a hoof on Twilight's shoulder. "I tell ya, Twi—without you findin' out about them changelings, I don't know what'd have happened."

You'd all be dead. The thought ran through Twilight’s mind like a venomous snake, and she shivered. She shook her head, doing her best to shake the thought from her mind. She was with her friends. They'd won. They were safe.

It was over.

With a flash of panic, she whirled back toward the Palace. The Princesses—

Yet there was no need. There was Celestia, proudly climbing the stairs to the top of the tower. Luna followed, ascending the staircase with a small smirk on her face. Beside them was a tall, black shape that Twilight recognized, with some surprise, as Chrysalis. Though she was once more in her natural form, the changeling’s wings were dented and scorched, and a scratch ran down her horn. Cuts and scratches covered her body, and light burns seared every other inch of her exposed skin. Twilight shuddered at the sight. It seemed like the changeling hadn't decided to come quietly this time. Still, it was better than the alternative.

"Princess Celestia! Princess Luna!" She galloped ahead and looked up at them with awe. "You beat her!"

"We did indeed overcome the foul beast," Luna proclaimed, looking down at Chrysalis with a curled lip. "She was powerful, but presented no real threat to my sister and I."

Chrysalis snarled, and Twilight noticed a sharp aura of fluctuating yellow and blue surrounding her horn. Undoubtedly, it blocked her from using magic or shifting form. "The 'foul beast' can hear you, you miserable old relic," she spat, and shot Luna a glare filled with loathing and disgust. With some surprise, Twilight noted that there was no more arrogance or self-assured confidence in her voice; instead, there was only hatred and the slightest hint of fear.

"Silence!"

A platoon of guardponies came up behind Celestia and bowed. One at their forefront stood back up and turned to the changeling with a stern glare. "You will not insult the Princess,” he growled. He offered Celestia a nod and waved a hoof in Chrysalis's direction. "Permission to take her to the dungeons and interrogate her, Princess?"

Luna stepped forward. "Granted. I will accompany you and maintain the magical shield." Chrysalis snorted loudly, and Luna turned back, a small smirk playing across her face. "Let this be a lesson to you on the 'softness' of Equestria, changeling. We do not respond well to those who threaten our security.”

As the platoon led the two of them down from the tower, Twilight looked up at Celestia and fidgeted with her mane. "Are you sure you're okay?"

Celestia laughed; to Twilight, it was like the sound of a rich harp, ringing through an empty room. "Of course I am. I admit, she was more powerful than I first expected, but by concealing Luna beneath a veil until you were in position, we were easily able to gain the element of surprise." She beamed. "You did wonderfully, Twilight."

Twilight felt something catch in her throat and she coughed to hide the tremor in her voice. "Thank you, Princess." She smiled back, at first hesitantly, and then with a grin that stretched from ear to ear.

"Oh, I almost forgot!"

She looked up at Celestia with wide eyes.

"Are there more changelings?" Pinkie asked, bouncing up to her side. She leaned forward and gasped. "Are we gonna have to kick their butts too?"

"I'd be down with that!" Dash flew up and landed on the ground beside her. She smacked one hoof into the other with a scowl. "I barely got to see any action as it is!"

Celestia threw her head back and laughed again. "Happily not, my little ponies. The guards have assured me that there are no more changelings in Canterlot."

"Then what is it?" Rarity trotted forward and paused, a hoof on her chin. "Have we missed something?"

Something twinkled in Celestia's eyes. "Not at all. I do, however, think that there's somepony who Twilight will want to meet."

Twilight took a sharp breath. "You mean—"

"Yes." Celestia gave her a small, happy smile and hummed quietly to herself.

Twilight made a run for it.

On she went, dashing down the stairs with the wind rushing through her mane and tail. She dodged past another platoon of guards, ignoring their cries of irritation and surprise. She had one thing in mind and one thing only.

With a joyous cry, she crashed through the doorway at the bottom of the steps and leapt forward.

"Twily!"

"Shining!" She galloped forward and held him in a tight embrace. He hugged her back, and she squeezed even tighter as if assuring herself that he was real. After a minute, she finally managed to stammer something out. "You—you're okay?"

"As I'll ever be." Shining smiled back at her, a goofy, boyish grin that she couldn't help but giggle at. "I was a bit out of it a few minutes ago, but Cadance knew a spell or two that could help clear my head out."

"I was so worried," she whispered, nuzzling his side. "I—I didn't know—“

“—If I was still in there?" He looked down at her and curled his neck around hers. "I didn't really, either. It felt like I didn't know who or what I was. For all I know, I would've been gone completely in only an extra hour or two."

Twilight shivered, feeling the hairs on the back of her neck stand on end. "But you're better now." She said it carefully, as though trying to force herself to believe it. For all she knew, she didn't.

"Yes." Shining held her tight, and she hugged back with all of the force she could muster. "I'm sorry for leaving you, Twily."

"Thank you for coming back," she whispered.

She felt a touch on her shoulder from behind. When she turned around, reluctantly letting her brother go, she saw Cadance again. A tired but triumphant smile covered her face.

"Thank you, Twilight," Cadance said earnestly. "I don't know how we would have won this without you rescuing me and stopping the changelings."

Twilight shook her head. "But my friends—"

Cadance held up a hoof. "They did a great job." She looked up over her shoulder and winked; Twilight turned around to see her friends by the door, waiting for her. "But I think we can safely say that you did one too."

With a roar, the thunderous chiming of bells rang out through the room. Twilight jumped, looking around the room in a panic. Given the circumstances, she almost expected the bells to herald Discord’s return or some similar disaster. "Wha—?"

"Ahem."

Celestia stood by the door and gestured to the dais with a wave of her head. She gave Twilight a wink before turning to the rest of the huddled ponies, the guests already beginning to return to their pews. "I believe we still have a wedding to finish?"

"So they said they'll write whenever they can?"

Twilight gave Fluttershy a short nod as they got ready to board the train. "Yep! I think they were going to honeymoon somewhere up north. Shining's always liked the snow."

Fluttershy shivered. "Ooh. I think that might be too cold for me. Still, I hope they have a wonderful time."

"I'm sure they will." Rarity trotted up to them with a heaping pile of luggage levitating beside her. It took Twilight a moment to realize that the telekinetic aura holding the pile was orange, not blue; a gangly-looking unicorn stallion stumbled alongside her, doing his best to keep the suitcases afloat.

Rarity sighed as the doors of the train hissed open and the group began to board. "Ah, true love. Such a beautiful thing, like a delicate flower."

Applejack snickered. She stood up on her hind legs and shoved her carry-on bag over the seats. "I think you've read one too many of 'em romance books, Rarity."

"Of course not!" Rarity sniffed and sat down in her seat with a soft thud. "Is there anything wrong with being a student of romanticism?"

"More of a sap than a student, if y'ask me."

Twilight plopped herself down beside her, struggling not to giggle at the other unicorn's reddening face. "Relax, Rarity," she said with a smile. "Applejack's just poking fun."

"Poking fun? Can I join in?" Pinkie popped her up head over the seat and prodded Applejack on the back of the head. "Poke! Poke! Poke!"

Twilight laughed far louder than the others, and as the train pulled away from the station, realized that the weight was gone from her shoulders. Her brother was safe. Her friends were happy.

She was—or soon would be—free.

The train didn't pull into the Ponyville station for another two hours. When it did, the group of friends waved goodbye and departed to their own houses. As Twilight walked down the dark road, Spike at her side and the stars hanging overhead, she smiled to herself as if laughing at a private joke.

That night in the library's bed—the first time she'd used it for, in her mind, weeks—she slept soundly. She dreamed of light, hope, and the happy future that lay ahead of her.

The sunlight prickled at Twilight's eyelids and she moaned, muffling her ears and eyes with a pillow. As a yawn forced itself to her mouth, she leaned up in bed and let the covers fall away. After rubbing her eyes to get the sleep out, she stretched out and opened them.

And stared.

"Oh, no."

The hanging curtains of her four-poster bed greeted her, drifting in the breeze that came from an open window.

"Oh, no, no, no."

Great spires and towers leapt to her eye from beyond the glass pane. Their purple flags waved proudly beneath the morning sunlight.

"No, no, no, no."

She threw off the sheets and leapt onto the floor, her head spinning. No. This isn't happening.

The vase, once more whole and unbroken, stood in its place on the dresser. The painting, with the jagged green line running down its center, waited in its place upon the wall. The two alicorns on its surface spun, chasing one another in a never-ending circle.

This can't be happening.

Twilight thrust her head out of the window and ignored the chill wind that blew through her mane. As she stared across the cityscape, the brilliant viridian Palace grounds stretching into the distance below, she felt her heart shatter.

"It didn't work," she whispered and turned away.