She wasn't at her library. She wasn't with Rarity and Fluttershy. She hadn't stopped by Sweet Apple Acres or Sugarcube Corner. Rainbow Dash hadn't seen her while clearing the sky. The most anypony could say is that she'd been speaking with a gray-coated Royal Guard, and that they had left the hospital and headed towards the Everfree Forest.

After hours of searching, Blueblood and Shining Armor finally found sign of her a half mile or so into the Everfree Forest: a blasted crater in the middle of a small clearing, accompanied by several scorch marks burnt into the sides of trees and rocks. The smoke and heat of the battle had long since dissipated, but the devastation was unmistakably the work of a powerful unicorn mage.

"Twiley?" Armor called, peering around the clearing. "Twiley, are you here?"

"Oh, dear," Blueblood muttered. Armor glanced at him curiously, then grimaced as the prince levitated a jagged, chitinous spike into the air.

"That's... that's a changeling leg."

Blueblood nodded. "Melted off at the stump. Twilight clearly wasn't holding back."

"But where is she? Twiley!"

Armor continued pacing the perimeter of the clearing, calling his sister's name. Blueblood, meanwhile, turned his attention to the signs of battle. He was no forensics specialist, or even a competent tracker, but he thought he could make out some of the details of the altercation. Twilight and the impostor Stalwart Shield likely entered from the same direction he and Armor had. Shield must have somehow organized an ambush ahead of their arrival. Judging by the blasts, Twilight had likely stood her ground in the center of what was, now, a crater. The various blast and scorch marks all seemed to have originated from roughly this spot. But why the explosion? Had Twilight triggered it, or...

"She's not here," Armor reported. He examined the battle site for a moment and frowned. "Why didn't she try to run?"

"What?"

"She stayed in one spot and kept firing forward. See how the trees and undergrowth are all scored in the same direction?"

"Actually, yes, I am capable of forming conclusions based on a set of facts."

Shining rolled his eyes. "If she held her ground and kept facing one direction, she thought her attackers were all coming from over there."

"Yes, obviously. So?"

"So, that's not like the other attacks. The other victims were jumped from behind. But Twiley was led into an obvious ambush. Maybe she saw it ahead of time, I don't know. But while she was focused on the ones in front of her, something big hit her from behind. Not big physically, but magically."

Blueblood nodded. "Hence the crater?"

"Yeah. See how it's angled slightly? The sneak attack came from behind, and above."

"Well, bravo, you're very skilled at reading crime scenes, but what does any of that actually mean? Of course they used different tactics for Twilight. She's rather more dangerous than any of their other targets."

"What that means, Blueblood," the knight growled impatiently, "is that they weren't screwing around with Twiley. They wanted to take her out, quickly and efficiently, and they were willing to sacrifice pawns to do it. She's not going to be beaten and left on Cheerilee's doorstep as a message. They know who she is, and they're not going to jeopardize things by treating her like the other victims. And that means that she's either captured and being held somewhere secure, or... "

Blueblood nodded grimly. "And supposing the former, we have a hostage situation."

"Yeah. 'Catch-and-release' isn't a safe game to play with the most powerful unicorn in Equestria."

"So... what do we do?"

Armor shook his head. "I don't know. I tried a tracking spell, but the changelings must've taken to the sky once they had her. I can't trace them through the air. Another capable unicorn mage might be able to use that limb you found to track its owner, if it's still alive. But, well, I don't think there are any around here, besides Twiley. So... I guess we go back to town, and I send a message to Princess Celestia."

"We give up?"

"We're not giving up," the knight said determinedly. "But we can't do anything else for her now."

Blueblood grimaced, but nodded. "Fine. But I'm done standing by the wayside while ponies I care about are hurt, Armor. When you find Twilight, I'm going with."

Shining raised a skeptical eyebrow. "That's a nice sentiment, but I don't need you getting in the way of guards who actually know what they're doing."

"I though we had declared a truce."

"It stands, but I'm being honest. You'll be more of a hindrance than a help."

Blueblood stamped a hoof in annoyance. "Then I'll stand in the back and be quiet, but I am going with."

Shining Armor conceded defeat with a roll of his eyes. "Fine. But you'll follow orders. I'm not going to have you endangering my sister's life."

"I'll do whatever it takes to bring her back safely."

"Good. Come on, let's get back to town."

A crowd had formed outside city hall by the time Blueblood and Shining Armor returned. The town's mayor, her mane a bit unkempt as she found herself pulled back from her impromptu vacation, stood at her podium outside the building. She was flanked by two official-looking ponies, one a green mare with a judge's gavel as her cutie mark, and the other a gray stallion with an open scroll.

"Citizens of Ponyville!" she called, straining to be heard over the chatter of a hundred or so worried ponies. "I assure you, as your mayor, that the rumors that the Equestrian Royal Guard has been overtaken by changeling impostors have little basis in reality!"

The green mare leaned in and whispered something into her ear. "Erm, no basis in reality, sorry. No basis."

"She's lying!" a mint-green unicorn shouted, standing up at the front of the crowd and turning to the assemblage. "Changelings disguised as guards foalnapped Twilight Sparkle, and Mayor Mare knows it! And if you're keeping that from us," she added, wheeling on the her target, "what else are you hiding?!"

The mayor sighed. "Miss Heartstrings, I can assure you... "

"Where are the humans, Mayor Mare?! Where are you hiding them?! Ponyville demands answers!"

A tan earth pony with a purple-and-pink mane stood, put an arm around the firebrand's neck, smiled embarrassedly at the crowd, and guided her away.

"I... should probably get up there," Shining Armor said with a sigh. He began circling around the crowd, trying to find a route to the podium. Blueblood, meanwhile, scanned the assembled ponies for any familiar faces. He spotted Cheerilee and Big Mac nearby, and headed over to them.

"What's this about?" he asked, sidling close to be heard over the continued noise.

"Rumor around town is that some of the Royal Guards were actually changelings," Cheerilee told him. "And that they were behind all of the attacks. And that you and Shining Armor were looking for Twilight. And, you know, that these events were related."

He nodded. "Well, as far as I know, it was only one guard, but... yes. We tracked Twilight into the Everfree forest, and found signs of a battle. We think she's been captured, or... "

Cheerilee frowned. "We're sticking with 'captured,' right?"

"Indeed."

At the front of the crowd, another pony, this one a unicorn in a plain-looking business suit, stepped up to the podium. His coat was a dour, flat green and his mane was a similarly dull olive. He looked over the crowd with a bored, accountantly expression. "Good citizens, please. Some of you may know me; I am Bank Ledger, of the Bureau of Infrastructure. I've been overseeing the repairs on your fine village. I can assure you, we have been working closely with the Royal Guard in their investigation into the recent attacks, and their loyalty and dedication to justice is beyond reproach. To suggest that there are changelings in their ranks is, well, simply absurd."

Somepony cleared his throat behind him, and Ledger turned to find Shining Armor standing there, looking haggard and exhausted and determined. "Mr. Ledger, if I may... ?"

"Of course, Captain," he said deferentially.

Armor took his turn at the podium. "Folks, I have to be honest with you. We have discovered an infiltrator among our ranks. We believe that he's been coordinating with the group responsible for the attacks on your good citizens, and Prince Blueblood."

A gasp rippled through the crowd.

"I'm contacting Princess Celestia herself for support in this case, but in the meantime, please exercise extreme caution. Use the buddy system; don't go anywhere without at least one other pony, if you can help it. If you have reason to suspect a friend or loved one may be an infiltrator, report your suspicions to a guard."

"But what if the guard's a changeling?" a blue unicorn with a white stripe in her mane asked.

"I'm going to begin screening all of my ponies immediately. Within a few hours, we should have any remaining infiltrators scoured from our ranks... though I have a feeling that they've already left."

A pink mare with a bright green mane raised her hoof. "Is it true that they captured Twilight Sparkle?"

He sighed and ran a hoof through his tangled mane. "I assure you, we will do everything we can to find any and all missing ponies."

The red-maned pony next to her raised hooves to her mouth. "Oh no, they did!"

"We're doomed!" shrieked the pink-and-blond mare on her right. Panicked murmurs began spreading through the crowd.

"Now, hold on a moment!" snapped an elegant, female voice. Rarity, accompanied by the remaining Bearers, had marched onto the stage. "I can assure you, if Twilight Sparkle is missing, she will not be for long."

Applejack tilted her hat roguishly and nodded. "Darn tootin'! An' no creepy li'l changelings are gonna run loose in our town, no sir."

"Especially not if they're the ones who've been hurting my friends," Rainbow Dash added, pounding her hooves together. "And, uh, Prince Blueblood."

"Yeah!" shouted Pinkie Pie. "We'll kick their bony, buggy butts right back to wherever they came from!" She paused. "Actually, where did they come from?"

"Um," said Fluttershy.

Shining Armor smiled at the Bearers, and turned back to the crowd. "I assure you, folks. Between my guards and the Elements of Harmony, not to mention assistance from Princess Celestia, Ponyville will again become the safest place in Equestria. But please, in the meantime, return to your homes, take the precautions I've outlined, and this will all be resolved before you know it."

Despite some discontented grumblings, the crowd gradually dispersed. Cheerilee turned to Blueblood with a questioning look. "So... back to my place to hold up?"

Blue caught Mac's eye, and said, in unison, "Nope."

"I'm helping Armor with this investigation," the prince explained. "And I'm going to be there when we find Twilight."

"Eeyup," said Macintosh.

Cheerilee gave her coltfriend a skeptical look, then turned it on Blueblood. "Why all the concern for Twilight, hm?"

Blueblood flushed. "You just had to tell her about the Wiggle Spear thing."

"I thought it was cute," she said with a grin. "So, you two... ?"

"It's... a bit complicated. I mean, I... like her rather a lot. But Blossomforth... "

She shushed him and put a hoof on his shoulder. "Okay, it's complicated. You can sort that out later. But if you two are staying, I'm staying."

"Us, too!" chirped somepony. They looked down to see the Cutie Mark Crusaders standing beside them, looking eager and determined.

"Us three," Apple Bloom corrected. "'Cause there's three of us, not two."

Sweetie Belle shook her head. "I said 'too,' not 'two.' They're different things."

Apple Bloom shrugged. "What's the difference?"

"They mean different things! 'Two' is a number, 'too' is... um, it's different."

Scootaloo rolled her eyes. "Your cutie mark's gonna be a dictionary, I just know it."

"Girls," Cheerilee said, velvet warning in her voice, "your enthusiasm is appreciated, but this is much too dangerous."

"But we helped with that Tyranny guy!" Apple Bloom protested.

Scootaloo nodded. "We kicked his flank!"

"That was only because we were in kind of a rush," their teacher sighed. "Princess Cadance would have dropped you off in Ponyville had she'd known you were going to attack that thing."

Apple Bloom stamped a hoof. "But it worked! An' maybe if we keep fightin' monsters, we can get our cutie marks in monster fightin'!"

"I... think I'd rather have a dictionary," Sweetie Belle said nervously.

"Girls, I'm sorry, but you can't come."

Blueblood rolled his eyes. "You do realize that they'll just end up following everypony into the woods and getting themselves in trouble, don't you?"

Cheerilee frowned at him, then looked back at her students. They were nodding enthusiastically.

"Oh, for the love of Celestia," she sighed. "Fine, you can come with for now. But if Captain Armor tells you to stay, you have to listen to him. Okay?"

They nodded again, then pantomimed crossing their hearts, flapping their arms, and sticking something in their eyes.

"This is going to end well," she said dryly. "Well, if we're going to save Equestria again, I'd like to get my hammer. Macintosh, will you come with me?"

"Eeyup."

"Follow me, then, girls," Blueblood said with a smile. "Let's see how Armor can incorporate you into his plans."

It was all Blueblood could do to keep from cackling. Poor, disheveled Shining Armor was utterly beset by the unflaggingly enthusiastic trio of fillies, his patience for their endless questions eroding by the moment. Fluttershy and Rarity had managed to corral them for awhile, long enough for him to write a letter to Auntie Celestia and post it via Spike, but eventually they'd taken an interest in Armor's changeling scanning spell and clustered around to watch and interrogate him about it.

So far, his prediction about any remaining infiltrators having fled seemed accurate. In addition to Stalwart Shield, three other guards had vanished from their posts, and Armor's spell had yet to yield any positive results. He was now nearing the end of his roster of sixteen remaining guards, and the effort, the lack of sleep, and the Cutie Mark Crusaders seemed to have him on his last hooves.

Taking a break from watching his rival's torment, Blueblood trotted over to where the Bearers were gathered and talking among themselves. They looked up at his approach, and the conversation immediately died out.

"Uh, hello," he said lamely.

Applejack nodded. "Hey, Blueblood. Somethin' ya want?"

"I... just thought I'd see how you ladies were doing, you know, without your nominal leader."

"Hey," Rainbow Dash scowled, crossing her hooves, "we don't need Twilight for everything. Like when we saved Fluttershy from those giant spiders!"

Rarity quirked an eyebrow. "You mean, when we found ourselves trapped and hopelessly outnumbered and undoubtedly would have perished without her timely arrival?"

"Um. Okay, bad example."

"Aw, face it, Rainbow," Applejack sighed. "We're all good at different things, an' we're a good team even without Twi, but she's always the ace in the hole when it comes ta dealin' with somethin' big. An' we couldn't fight an army of changelings even with her." She turned to Blueblood. "So, yeah. I reckon we're a bit worried. 'Bout her, an' about mountin' any kinda rescue."

"Well, for what it's worth, you have Shining Armor. He's not as versatile a spellcaster as Twilight, but... "

Fluttershy frowned. "He's very brave, but he also looks really tired."

"Yes," Rarity agreed. "Honestly, I think the best thing he could do for Twilight right now would be to get a few hours' sleep."

Blueblood nodded. "Maybe once he finishes his scanning spell, he'll spontaneously develop enough brain cells to consider the idea."

"I think it would help if we rescued him from the girls."

"I'll get them," Fluttershy said, pushing herself to her hooves and trotting off.

Rarity watched her go, then turned to Blueblood with an eyebrow raised. "I'm surprised you're so concerned for Twilight, Your Highness. I would have expected you to avoid potential danger."

The prince sighed and rubbed the back of his head. "I've already explained things enough today. Suffice it to say, I care about her, and I want to be present when we rescue her."

She gave him a considering look. "I see."

They all jumped as Pinkie Pie suddenly sprang into the air. "Hey, it's Ditzy-Derpy-Doo-Hooves!"

All eyes turned to the front doors, where a wall-eyed pegasus mare with a mailbag slung over her back stood with a somewhat confused smile. "Um, hi? I've got a letter for Captain Shinning Armoire. Er, Shining Armor." She giggled. "Sorry."

"That's me," Armor said wearily, plodding over to her. "Is it from Princess Celestia?"

"Um, no, I don't think so. It was just sittin' in my delivery box, so I came here to deliver it!" She reached into her mailbag and pulled out a large envelope, passing it to Shining. He used his magic to tear it open and unfold it.

"It's a ransom note," he said after a moment.

Everypony leaned forward expectantly.

"Hey, I've never delivered a ransom note before!" chirped Ditzy. "Um, I'm not in trouble for that, am I?"

Armor waved vaguely at her concerns. "That's odd."

"What?" Blueblood asked.

"There aren't really any demands. They just want... you, Blueblood."

"What?"

"My Dearest Shining Armor," he read aloud. "I apologize for having to involve your sister in this little affair, my love. I hope it doesn't cause a divide between us, after the intimate moments we've... " He coughed. "Uh, skipping a bit.

"If you want your sister back, as I'm sure you do, I have but one, simple request. I'd like to speak to your good friend, Prince Blueblood. Alone. Have him walk towards the zebra's hut tonight, after sunset. I'll meet him along the way. And I promise, you'll be reunited with little Twiley before you know it. Until we meet again, my handsome hunk of horseflesh... " He sighed. "Ignore that last part, please. It's signed, 'Chrysalis.'"

"It's a trap," Applejack said flatly.

"It's a very obvious trap," Rarity agreed.

"Pretty sure that 'you'll be reunited before you know it' part's a threat, too," added Rainbow Dash. "Sounds like something Ahuitzotl would write." She crossed her arms at the blank looks she received. "Seriously, read a book, ponies."

"I'll do it," Blueblood said.

Everypony turned to stare at him, with expressions ranging from reproach to simple disbelief. He shrugged. "I mean, I'd prefer you had some sort of plan to protect me, capture her, and find out where Twilight's being held, but I'm certainly willing to play the bait, here."

Shining frowned. "It's still a bad idea, Blueblood. We don't know how much power Chrysalis got to hang on to after Cadance and I drove her out of Canterlot. She took down Princess Celestia, remember?"

"She won't this time."

All heads turned again to the front doors, where three tall, supernaturally beautiful ponies stood with their faces set in grim determination. Princess Celestia, her ethereal mane billowing in the still air behind her, stepped forward. "This madness has gone on long enough, my little ponies. Tonight, it ends."