Silence reigns as Luna, Twilight, Midnight, and Rainbow Dash stare at the horn, all of them starting when it emits a sharp snake-like hiss and dissolves into thick black smoke. The dark mass quickly expands to fill the entirety of the shield, tendrils forming to press and prod at various parts of its prison in search of a weakness to exploit.

"Huh. Well that was unexpected," Applebloom comments.

Twilight's ears stand straight up as the voice of the Apple family's youngest member drags her attention from the newly filled barrier to the Crusaders standing just a few steps behind her. Closing her eyes for a moment, she mentally kicks herself, Great, just great, not only was I actually right about Sombra, but I let four fillies watch Luna kill another pony. Or whatever this would count as. Annihilate another pony? End another pony? Well in any case…

"Girls," Twilight says, turning to sternly address the still gawking fillies, "you need to go to the town square right now. And I mean actually go there this time."

While she speaks, magic crackles across Sombra's prison accompanied by an incomprehensible echoing whisper as he continues testing the limits of the spell containing him.

Flinching at her tone as much as the remnants of the deposed tyrant, Scootaloo nervously salutes along with Sweetie Belle and Applebloom, "You got it, Twilight."

The trio starts to run down the street until Applebloom suddenly stops and turns around, "Hey Dawn, you comin'?"

Dawn glances at the waiting fillies, then uncertainly back at her sister.

Midnight gestures with her head to follow them, "Go on."

Casting one last worried look at her sister, Dawn joins her friends and they soon vanish around a corner as they head towards their original destination.

Watching the four complications leave her sight, Twilight closes her eyes and fills her lungs with air, placing a hoof to her chest. After holding that pose for several seconds, she moves her hoof away and slowly exhales, though what little stress the action manages to relieve instantly returns as soon as she reopens her eyes.

"Luna," Twilight says, returning to the matter at hoof, "this whole 'Sombra getting destroyed and transforming into smoke' thing is very similar to what happened last time you and Celestia defeated him, right?"

"It is," Luna confirms.

"And last time, according to Princess Celestia, it caused any remaining undead vamponies to go berserk, right?"

"It… " Luna's eyes widen, "Oh."

As if on cue, her three Lunar Guards land and bow to their princess, "Your Highness, we have found no trace of the pony you described anywhere in Ponyville."

"He is no longer of any concern," Luna replies, waving away their no longer relevant information. "Have you seen any other similarly suspicious characters or activities?"

The lead guard shakes his head, doing his best to keep his eyes on Princess Luna and not the swirling shadow behind her, "We have not. With the exception of one house blasting some sort of strange classical-electronic music, the entire town was completely silent until a couple minutes ago, and this is the last section we have yet to sweep."

Relief washes over Luna at their words and she nods, "Good. Continue searching and report back to me if you find anything."

The guards salute and take to the air once more.

"Rainbow Dash, Midnight." Luna turns to the other fliers, "I want both of you to continue searching as well. You both know this town far better than my guards and may think to look in places they would not."

Midnight sends a concerned glance at Rainbow, but nevertheless jumps into the night sky and vanishes.

Rainbow Dash stands as Midnight takes off, gritting her teeth and shifting her weight onto her good legs to ease the growing pain spreading through her bitten one. Thin arcs of lightning travel across Luna's shield as the smoke once again tries – and fails – to escape, a familiar pair of green eyes with red pupils forming in it after the attempt.

"Twilight," Luna says, breathing heavily from the effort of maintaining her barrier, "we cast this spell quickly in order to contain the undead vampony, but it is highly inefficient and very difficult to maintain, especially against somepony with Sombra's abilities. Therefore we require your assistance in creating a more permanent solution."

As Luna speaks, the pair of floating eyes wander from the two alicorns to settle on Rainbow Dash, the pegasus' leg beginning to pulse with a dull throb in time with her heartbeat.

Rainbow gulps and diverts her gaze from the eyes, "So, uh, Twilight, what was that about the undead? Why is Sombra here? What the hay is going on!?"

"Not now Dash," Twilight replies without even glancing up at her friend. "What did you have in mind Luna?"

Rainbow's vision blurs and she rubs her eyes, "But it's kinda important-"

Twilight sighs in frustration, "Look, I know this seems really strange right now but believe me, everything is going to be fine. Sombra's been captured and he's going to stay captured."

"We were thinking one of Starswirl's ambiance-sustained containment barriers, if you have the materials available," Luna suggests.

Twilight rubs her chin as she mentally runs through her inventory of magical supplies, "Hmm, I should have everything on hoof. If not, I can definitely pull whatever else we need from some of my past experiments."

Rainbow frowns and again opens her mouth to speak, however Twilight vanishes with a purple flash before she can get a word in edgewise.

"Was there something you wished to say?" Luna asks, glancing up at her.

Luna's attention is diverted before Rainbow Dash can answer as Sombra once more strains against his prison, small cracks forming in multiple places on the sphere. Luna grunts, beads of sweat forming on her face while she struggles to keep the shield from shattering. Once Sombra's attack subsides, she sits heavily, her head lowered as she pants from the exertion.

"Uhh… no, it's fine, it can wait until after you and Twilight make that ambi-whatever," Rainbow says uneasily. As soon as she speaks, her vision swims and nausea rises in her stomach, "I think… "

A minute later, Twilight teleports back in another flash of purple with several lumpy bags held in her telekinetic grasp. Rainbow Dash sways, blinking away the lingering afterimage as Twilight places the bags next to Luna and unloads several blank runestones, transparent focus crystals, and deep blue amplification gems.

Luna nods tiredly, "That should suffice. We will need you to take over containing Sombra while I set up."

"Of course," Twilight walks over to stand next to Luna, the shield glowing purple as the pair touch horns.

"Oof, you weren't kidding about it being inefficient," Twilight jokes as they separate. However her attempt at humor is lost on Luna who sighs with relief at the removal of her arcane burden, closing her eyes for several seconds to rest and refocus on her new task.

Levitating four of the runestones to lay on the grass in front of her, she lowers her glowing horn to the closest of the set for several seconds, dim white lines originating from their meeting point to move seemingly at random across its smooth surface. As Luna moves on to the next runestone the white lines fade from the first, a few thin strands of smoke rising from the matching engravings. Once identical runes have been carved onto all four stones, she embeds them in the ground to form a square around Sombra's purple prison. The focus crystals follow, Luna carefully placing them on either side of each runestone one quarter of the way along an arc to form part of a circle. The amplification gems complete the circle, one centered between each pair of focus crystals.

Unnoticed while Twilight concentrates on maintaining the current shield and Luna works to create a new one, Rainbow Dash slumps to the rooftop, the world bending and twisting before her eyes as a haze starts to fill her mind.

After walking a lap around her circle to examine her work, a ball of energy gathers at the tip of Luna's horn and four beams of white light simultaneously shoot out to hit each of the runestones. Tendrils grow like roots from their surfaces to dig into the earth and air before fading from view to leave the runestones thrumming with magical energy. As soon as Luna ceases her magical injection, the air chills, twin beams shooting from each runestone to pass through the focus crystals which narrow the beam and direct it at the amplification gems. The blue gems rise to float just above the ground glowing brightly, an identically colored beam of energy arcing from each to strike the existing barrier containing Sombra. A second layer of magic grows from those four points, quickly merging with each other to complete the new shield.

"You may release your spell now, Twilight," Luna says as the air begins to warm.

Twilight does so immediately, her shoulders sagging tiredly as Luna's original barrier disintegrates. The smoke pushes against its newly constructed prison, but apart from a small drop in temperature nothing happens, the air beginning to warm again as soon as the escape attempt ends.

Luna allows herself a weary but satisfied smile before she starts to walk another lap around her activated spell circle, horn pulsing dimly against the thrumming backdrop of magical current as she probes for any slight defects.

Sighing, Twilight rubs her eyes and looks down the street away from the floating sphere – straight into Pinkie Pie's smiling face.

"Hi Twilight!"

Twilight jumps nearly a foot into the air and her wings snap open, somewhat slowing her short descent. Hearing her heart pounding loudly in her ears, she forces herself to take several long, deep breaths, the mad beating in her chest gradually slowing, "Pinkie! Please don't do that. Tonight of all nights."

"Okie-dokie-loki," Pinkie replies happily as her eyes roam across the scene in front of her, smile shrinking at the sight of Sombra.

"What are you doing here anyway?" Twilight asks quizzically, "You couldn't possibly have woken everypony up yet."

"Weellll… most of the ponies I woke up were pretty annoyed about it, seeing as it's late and all, but once I explained what was going on they were really understanding and some even started helping out! So when the moon suddenly got super bright I told told them to finish up and I'd investigate. So here I am!" Concern replaces Pinkie's smile as her eyes move from Sombra to the adjacent roof, "By the way, what's wrong with Dash?"

Twilight blinks in confusion and finally looks up at her many-colored friend, "What do you mean what's wrong with – Dash!"

"'s fine," Rainbow slurs from her perch, "'m totly fin"

"No you are NOT fine. Now get down here so I can see what's wrong," Twilight demands worriedly, faint warning bells going off in the back of her mind.

When Rainbow's only answer is a gurgling groan, Twilight lifts her friend from the roof with her magic and gently lays the pegasus on the ground. Her jaw drops as she sees jagged black lines of lumpy flesh stretching the length of Rainbow's leg and beginning to spread across her barrel as if fire flowed through her veins instead of blood, burning her from within, "Lunaaa!"

Luna glances up from her examination, "We are standing right here, Twilight; there is no need to yell."

Twilight paws at the ground, "What… does it look like when a pony gets bitten?"

Luna is beside Twilight fast enough to have teleported, the lack of a telltale flash the only indication she hadn't done so. She gasps when she sees Rainbow's injury, "It can appear similar to that."

Twilight backs up a step and turns in a circle as panic sets in, "Nooo nonono, how do we fix her? Cure her?" She looks up hopefully, "Luna?"

Fear twists in Luna's gut, but with a grimace she forces the unhelpful emotion into the background, "I… we do not know. Never before have we seen it behave with such… virulence. In our limited experience with the turning process, it only ever succeeded when the pony bitten was near death already, in which case there was little point in trying to save them and even then the scarring was nowhere near this severe. In a healthy pony it should be almost indistinguishable from a common cold which vanishes on its own after a few days."

Twilight whirls around to glare at Sombra, "What did you do to her?"

The tyrant's shadow merely laughs, Rainbow Dash yelling in pain as the lines of corrupted flesh pulse and spread further across her body. Pinkie watches expressionlessly as her friend slowly relaxes when the pain subsides, her mane flattening to reach her knees.

Luna places a hoof on Twilight's shoulder, "Perhaps the Elements would be of use? They were able to purge me of the corruption which led to my becoming Nightmare Moon after all, and what is happening here is as disharmonious as anything I've ever encountered."

"Twilight!" a familiar voice calls from behind them, "Whatever is making that absolutely awful noise? And where did that disgusting smoke monster come from? Though I suppose that answers my first question, doesn't it?"

Relief rushes through Twilight as she turns to see Rarity and Fluttershy trotting towards her, "Have either of you seen Applejack?"

Rarity shakes her head, "No, we haven't. She ran all the way out to Sweet Apple Acres remember? Is something the matter?" She pauses, "Also, is that thing… staring at me?"

Fluttershy's eyes widen upon seeing Rainbow Dash and she raises a hoof to her mouth, "Oh my… "

Rarity's eyes shift back and forth between the smoke and Rainbow, "Twilight, dear, what's going on?"

Her query bounces impotently off Twilight's stress-muddled mind as she focuses on a different question, How do I find Applejack? How do I find Applejack? How do I-

"Hey girls, Ah came as fast as Ah could. What's goin' on? Why'd the moon get all bright?" Applejack asks, running up to the group from the opposite direction as Fluttershy and Rarity. Her ears lower as she sees Rainbow lying on the ground, "Scratch that, what's wrong with Dash? She don't look right."

A feeling of displacement answers her questions rather than words, Twilight pulling her 5 friends along into a group teleport.

A nervous minute passes as Luna stares at the place they had been, then up to her moon, Good luck, Twilight Sparkle

Unable to sit still any longer, Luna resumes her examination of her circle only for Spike to run up a few minutes later.

"Princess… Luna… have you seen… Twilight?" Spike asks between pants, falling to his hands and knees then onto his side as he gasps for breath.

Luna nods, "I have, they just left in fact. I do not know exactly where to for certain, though I would expect them to be entering the Everfree Forest by now."

Spike groans at the thought, opting to remain on the ground rather than continue his pursuit. The door to one of the houses beside Sombra's prison opens as he lays there, Berryshine peeking out with a fresh chair clutched in her hooves. She jumps at the sight of Luna, dropping her chair and bowing, "P-Princess!"

Spike raises his head and waves, "Hey Berry."

"Since neither of you are doing anything else at the moment, could you both begin waking the ponies on this street and direct them to go to the town square?" Luna requests.

Spike shrugs and gets to his feet, "Sure."

Berryshine rises from her bow, "Of course, Princess."

Sombra struggles to break free once more, dark whispers at his failure finally drawing the attention of Spike and Berryshine. They stare at the shadow. The shadow stares back.

"AAAAAAAAAAAAAAAAAAAAAA!!!"

Chaos explodes through the Golden Oaks Library as soon as Twilight and her friends appear – books, chairs, and all manner of other movable objects flying through the air at random while Twilight frantically darts around her home, skimming through the moving projectiles.

"So Twilight," Applejack ducks, a lamp just barely missing her hat, "are ya gonna explain why we're here? Or what's wrong with Rainbow Dash?"

"Or what that awful smoke creature was?" Fluttershy adds as she pulls a slowly tumbling Owlowiscious from Twilight's magic and into the relative safety of an empty bookshelf.

"Hooo-oo"

Fluttershy smiles, "You're very welcome."

Rarity steps aside to dodge a slow-moving table bearing Pinkie Pie, "Or perhaps you could start with why you're trying to smash us to bits with this maelstrom?"

"QUIET!!!" Twilight shouts, silencing her shocked friends as the floating objects cease their movement. "I need to find where I put the Elements so we can cure Rainbow Dash and all your talking isn't making it any easier!"

Her friends share an uncomfortable look before Pinkie speaks up dully, her mane still flat, "Then why are we here? We gave the Elements back to the Tree of Harmony, remember?"

Twilight's right eye twitches and several tufts of hair pop out from her well-combed mane, everything falling to the floor as her magic cuts out causing several of the more delicate objects to shatter, "But that – but we – we need the Elements to fix Rainbow, and if they aren't here, if they're in the Everfree Forest, teleporting myself that far through so much chaotic magic is already incredibly dangerous and teleporting all six of us is impossible but if we don't get there, if we don't-"

A scream interrupts her, Rainbow Dash's corruption spreading again to reach halfway up her barrel. Twilight's mouth hangs open as she stares at her dying friend, her brain both trying yet unwilling to go any further down that path.

Applejack walks over and snaps Twilight out of her daze with a light punch to her chest, "Hey, now Ah may have absolutely no idea what's goin' on right now, but what Ah do know is that we still represent the Elements even if we don't got those fancy necklaces or crown anymore. So what do we need to do to save Rainbow Dash?"

Twilight swallows and shakes her head as she reorganizes her thoughts, "Right… you're right, Applejack; we do still represent the Elements, so we should be able to channel them at least a little bit. OK, everypony form a circle with Rainbow."

I just hope it'll be enough.

Twilight, Applejack, Fluttershy, Pinkie Pie, and Rarity arrange themselves in a circle to include a barely conscious Rainbow Dash, Pinkie Pie's mane re-poofing determinedly as she reminds herself all the pranks she and Rainbow had pulled together over the course of their friendship. Closing their eyes, each of the five focus on their element and begin to levitate a couple inches off the ground, a light breeze swirling around the half-demolished library as they link to their neighbors with a faint rainbow.

As their connection to their element and each other strengthens, black wisps leech into the air to form a haze around Rainbow Dash, absorbing the rainbow from Twilight and Rarity to prevent it from reaching their friend. The other connecting rainbows begin to flicker at the interruption and after a second the channel abruptly ends, dropping them all back to the floor.

"What happened?" Rarity asks worriedly, "Twilight, why didn't it work?"

"I don't know," Twilight says, feeling herself starting to panic for what seems like the umpteenth time. "It should have worked. The entire purpose of the Elements is to spread harmony, so the only reason I can think of that it wouldn't have worked is it's become too ingrained to be removed without the actual Elements of Harmony."

"So what's gonna happen to RD?" Applejack asks, doing her best to hide her shivering as she shifts shakily from hoof to hoof.

Twilight blinks away tears, "She's going to die."

Well, not quite, a part of herself whispers unbidden from a dark corner of her mind. It's your job to grant her that luxury now.

Taking one last look at her friend, Twilight charges her horn, Rainbow Dash spasming as the corruption spreads again.

"Um… I have an idea… "

Four pairs of eyes meet Fluttershy's.

"Well… I was just thinking… maybe if we tried making a circle around Rainbow Dash instead of with her it might work better, since she'd be connected to all five of us instead of just two?"

Twilight stares at Fluttershy dumbly for a second, then grins widely, gleefully letting the magic leave her horn, "Fluttershy you're a genius!"

Their hope rekindled, Rainbow's five friends gather around her and focus on the elements they embody once more. Levitating a couple inches from the ground, a faint rainbow again passes between Twilight, Applejack, Fluttershy, Pinkie Pie, and Rarity – strengthening when the circle is completed. They rise a further few inches as the breeze swirling around them intensifies and they start to glow, Rainbow Dash beginning to be drawn up as well as five rainbows arc down from her friends to struggle against the black haze forming around her. This time however the unity of her friends holds firm, the shadow surrounding her losing ground until one, then two, then all of her friends connect.

A brilliant white cocoon envelopes Rainbow, an eerie screech echoing around Twilight's library as Sombra's poison is purged from her body. Finally free of the corruption, Rainbow Dash rises to join her friends, the light of the cocoon spreading throughout the entire room before the six slowly descend back to the floor.

Author's Notes:

I seem to have earned that Dark tag more than I ever intended with this chapter…

Also I can neither confirm nor deny forgetting that the Elements were in the tree when I first wrote this out