A/N: So this fic was a request by the wonderful Lillelouis from…3 years ago? Jesus. I'm so sorry that this took so long – real life can be a bitch, sometimes.

I normally don't post fics until I've finished writing them, but I'm making an exception for this one since I'm currently 40k into it with no end in sight. My motivation is flagging a little but I definitely want to finish it so I thought I'd post the first few chapters to kick myself into gear. This does mean that updates will be slower than usual, though, since my aim is to finish at least one new chapter before polishing off an old one and posting it.

Title is shamelessly stolen from a S2 episode of Supernatural (which in turn stole it from a Led Zeppelin song). Also, I apologise for the complete bastardisation of fairy lore found in this fic – liberties have definitely been taken, in true Teen Wolf fashion.

I hope you enjoy!

What Is And What Should Never Be

Chapter 1 – And Fairies, Oh My

How was it, Stiles wondered, that it always ended up like this?

It didn't seem to matter how much he grumbled or how many deities he half-heartedly begged. Somehow, he always found himself trudging through the woods in the middle of the night hunting down the latest God-knows-what to terrorise Beacon Hills.

He huffed, adjusting the flashlight in his left hand and hefting the iron poker in his right, then rolled his eyes as he heard a soft chuckle from nearby. "I'm glad you find this amusing," he grumbled, not bothering to look around.

"Sorry." Scott didn't sound remotely apologetic. "It's just that you used to be the one dragging me through the woods against my will, not the other way around."

"Yeah, well, that was before I realised that I'm a puny human in world full of supervillains. I've garnered a little respect for self-preservation."

Scott made an unconvinced noise but otherwise let the conversation slide, the silence broken only by the thud of their footsteps – Stiles' noticeably louder than Scott's – and the soft rustle of leaves in the breeze. Stiles couldn't hear any animals at all – he suspected they were keeping well clear of Scott's werewolf scent.

On any other day, it would have been peaceful.

Stiles' skin prickled, and he shuddered. Peacefulness had always made him nervous – the calm before the storm - and the last few years had only cemented that instinct. The threat was always just around the corner, invisible and inevitable, and the anticipation was almost worse than the confrontation itself.

Stiles had never been good at waiting, so he forcibly unclenched his jaw and cast his mind for a distraction. "So, Deaton's sure that it's a fairy?" he asked, letting the words tumble out thoughtlessly.

To his left, he saw Scott tilt his head in concern. The werewolf had no doubt been flooded by his anxiety-driven chemosignals - as if Scott ever needed help reading him to begin with.

"He seems to be," Scott replied after a beat, shaking his head in bewilderment and apparently choosing to leave it be for now. "I'm still having trouble wrapping my head around it, honestly. I mean, fairies? Really?"

Stiles snorted. He could feel the tension melting from his shoulders as he eased into their familiar banter. "You always have been ridiculously sceptical. With all the weird shit that's happened in the last week, are fairies really so crazy?"

Weird shit didn't even begin to cover it. Stiles had watched, wide-eyed, as a group of annoyingly loud students suddenly froze in the cafeteria, unable to move or speak for an entire hour. Then, during training, he had been forced to run for cover when lacrosse balls started flying by themselves, interrupting Coach Finstock's passionate rant.

Magical outbursts - that was what Deaton had called it. Stiles had listened, bemused, as the vet explained that many people were born with a certain potential for magic, an untapped talent that would typically remain dormant for a lifetime. The arrival of the fairy had changed that.

Deaton's cryptic explanation had left Stiles with more headaches than answers, but he understood the gist. Wherever fairies went, magic followed. They changed the world to be more like theirs, calling forth every speck of magical potential until it spilled uncontrollably into the surroundings.

It sounded fantastical – poetic, even. A year ago, Stiles would have been bouncing off the walls with excitement at the mere thought that magic existed, let alone fairies and other worlds.

Now, though, he was stuck trudging through the woods while his thigh ached from where Coach's so-called magical potential had thwacked him with a lacrosse ball, so he mostly he just felt tired and grumpy. Reality had no room for poetry.

Scott suddenly perked up, his gaze fixing on something in the distance and his shoulders relaxing. Finally, Stiles groaned internally. They must be almost there.

Sure enough, it was only minutes later that Stiles spied two small lights up ahead, and when he strained his ears he could just make out the girls' voices.

"Do you think you can track them?" Lydia was asking.

"I'm not sure." There was an edge of frustration to Malia's voice. Scott and Stiles shared a worried glance, picking up the pace until the trees thinned into a sudden clearing.

Malia was crouched at the opposite end of the clearing, trailing a hand along the surface of a smooth rock. Her brow was furrowed, and she was biting her bottom lip in confusion.

"What is it?" Scott asked, sparing a quick smile for Lydia before heading over to join the werecoyote.

Malia fell back on her heels, gesturing for him to crouch beside her. "I've been tracking their scents but…this doesn't make sense to me. Have a look; tell me what you think."

Tracking had never been Scott's forte, so Stiles figured it was best to give him some space. He made his way to Lydia instead, taking in his surroundings with keen eyes as he went. The ground was unusually even, he noticed, with no potholes or slopes to trip his feet. In fact, there were no rocks or sticks marring the springy grass beneath his feet, and he couldn't see any leaf litter in his torchlight at all.

Lydia had chosen to stand in the centre of the clearing, and when Stiles reached her he shifted his light from the ground to waist-height, then slowly rotated.

Huh, he thought, impressed. Dad was right. He couldn't see particularly well in the dark, but the tree trunks seemed to be roughly the same distance away from him whichever direction he turned. It was as though the clearing was a perfect circle.

"It's all wrong," Lydia murmured. Stiles turned his attention back to her, surprised to find her sharp eyes fixed on his. "You see it too?"

Stiles nodded, shivering a little. It must be the cool night air. "Yeah. There's something off about this place – even Dad noticed that. Whatever it is, it's not natural."

"It's more than that." Lydia frowned, pushing an errant lock of hair behind her ear in an irritated fashion that betrayed her discomfort. "This whole place looks innocent, but it reeks of danger. It's like there's something hiding, just waiting beneath the surface."

This time, Stiles' prickling skin was definitely more to do with anxiety than the temperature. His heart skipped a beat as something stirred in his chest, and for a moment he could have sworn he heard thunder in the distance, but he stamped down on his emotions and tried to focus instead on the facts.

"Okay," he said, taking a moment to collect his thoughts. "Well, Dad said that they planned to come this way on their hike. Apparently, Josh had found a spot he thought was romantic. If you ignore the creepy-as-hell vibes that this place is giving off, I guess this could be it."

Lydia crinkled her nose, poking the ground distastefully with the toe of her boot. "I suppose. If your definition of romance involves walking through the woods for two hours and spending your entire date fending off mosquitoes."

Stiles grinned. "Noted. Do not take Lydia Martin hiking, unless you're expecting to find werecoyotes or dead bodies at the end."

Lydia rolled her eyes, but her lips twitched in the slightest hint of a smile. "I could do without the dead bodies, too, you know," she deadpanned. "Call me old-fashioned, but dinner and a movie sounds much more appealing."

That prompted a small laugh. "I'll keep that in mind." A soft breeze ruffled Stiles' hair and he pursed his lips, turning back to the matter at hand. "Not tonight, though," he added, softly. "Josh and Sarah have been gone for over a day now. Do you feel anything else?"

Lydia's mouth tightened, her levity forgotten. "This is definitely the place," she pondered. "It's not natural, and the circular shape would fit with Deaton's fairy theory. But I don't think anyone died here."

"Well, that's something," Stiles replied, trying to inject some optimism into his voice. "If they're still alive, there's still hope."

The banshee didn't share his excitement. "Maybe."

Stiles narrowed his eyes. She had that distant look in her eyes, the one that said that she was mulling over something, chasing a chain of ideas faster than he could follow, and he didn't think he was going to like where she ended up.

He opened his mouth to ask her to share her thoughts, but snapped it shut again when she closed her eyes, her forehead creased in concentration. She was breathing slowly, deliberately, in a way that always made him squirm in discomfort.

He didn't think he would ever get used to watching her use her powers.

Still, she was obviously trying to work through a theory, so he waited quietly, studying her intently, until something heavy landed on his shoulder and he jumped a foot in the air, biting off a curse.

"Jesus, Scott!" The werewolf in question was standing beside Stiles, one hand outstretched and a marginally apologetic look in his eyes, Malia a few steps behind. Stiles clutched his chest, trying to slow his panicking heart. "Warn a guy, next time!"

"Sorry," Scott replied automatically, not sounding particularly apologetic.

Stiles glared at him.

Malia pushed forward, interrupting them before they could even get started. "They never left here," she announced. Her lips were thin, her eyebrows pulled together in an irritated frown. Stiles knew that look well – it was the same expression she gave to her maths textbook when she was struggling with a new concept. It was a look that she reserved for times when something should be making sense, but wasn't.

Stiles' heart sank. It was a look that didn't bode well for their little investigation.

"Sarah's perfume is all over the place," Malia explained. "They came from over there –" she pointed to the side of the clearing where Scott and Stiles had entered – "but the trail ends here. There's no blood and no sign of a struggle. So, either they retraced their footsteps back to town, or they just vanished into thin air."

Stiles exchanged a grim expression with Scott. They had been through too much in the last few years to ever expect an easy answer.

"What about the chemosignals?" Stiles prompted. "Any fear, pain, anything?"

"Fear, yes," Scott answered, before shaking his head. "But nothing else. If they were captured, there would probably be pain, right?"

"Not necessarily," Lydia countered. She must have abandoned her banshee efforts when the others arrived, her eyes sharp and clear as she turned the information over in her mind. "Fairy lore has twisted and changed over the years, so I don't really know what parts are real. But abductions and the use of magic are common staples."

"Right," Stiles added, picking up her train of thought and running ahead. "Fairies aren't from our world, they live in their own dimension. Depending on what brand of mythology you look at, they could have all sorts of magical abilities – they could easily be able to take people without causing pain. They're also famous for kidnapping humans and bringing them back to their world, sometimes as companions, sometimes as playthings."

"Playthings?" Malia twisted her mouth in disgust, backtracking rapidly. "Actually, never mind. I don't want to know."

"No, probably not," Stiles agreed. "But if we assume that Josh and Sarah have been taken to another dimension, the more pressing question is how to we get them back? No offense, but I don't think claws and fangs are going to be able to do much against super-powerful magical beings."

"Actually, I don't think we'll have to do that," Lydia said. Her eyes drifted down to her feet and she shifted her weight, clearly reluctant to voice her thoughts, but she continued anyway. "I've spent the last day trying to feel whether Josh and Sarah had died, and I've gotten nowhere," she explained, quietly. "But if they didn't die here, if they were really taken to another dimension, then it would sense that I wouldn't feel their deaths. So, just before, I tried something different. I tried to feel whether they were still alive."

She paused for breath, green eyes radiating pain as she finally lifted her gaze. "They're not. I know my abilities haven't been the most reliable in the past, but I'm right about this. I'm sureof it. We're too late."

Her voice was steady as a rock and Stiles' heart sunk, a distant rumble of thunder perfectly complementing his emotions. He hadn't really known the couple – they were a year older and weren't the type to associate with awkward nerds like him – but he knew they didn't deserve to die.

Sarah Romano and Josh Duhls. Two more names to add to what felt like an ever-growing list.

He rubbed his chest, absently trying to calm a writhing heat that had ignited within, and tilted his head curiously at Malia. The werecoyote was staring at the sky with the same annoyed expression from earlier.

"Malia?" he asked, cautiously. "What is it?"

She glanced at him, then gestured at the sky. "There's no clouds," she pointed out. "There's thunder, but it's a clear night. Something's off."

She was right, Stiles realised. His heart fluttered nervously, heat expanding further in his chest. "The fairy?" he suggested.

"It has to be," Scott agreed, an edge of anxiety to his voice. "Come on, let's get out of here."

Malia led the way, heading back toward town at a jog slow enough for the humans to keep up. Lydia followed close behind, surprisingly sure-footed, then Stiles, with Scott bringing up the rear. Once, Stiles would have been irritated at the protective positions the werewolves had taken. Now, though, all he felt was gratefulness.

They hadn't gone far – less than a mile – when Malia suddenly drew to an abrupt halt, letting out a loud curse. Lydia and Stiles pulled up short, Scott blowing past them to take the lead.

Stiles didn't hurry, taking a moment to catch his breath as he met Lydia's grim expression with one of his own. He had a feeling he knew what had happened.

Carefully, Stiles stepped forward and closed his fingers around Lydia's hand, and together they moved to catch up with the others. As soon as they drew even, they could see what had prompted Malia's shout.

Stiles was expecting it, but his stomach still plummeted at the sight. It was another perfectly round clearing – the same one they had just left – materialised right in their path.

"We're too late," Lydia murmured, and Stiles nodded in agreement.

Scott turned his attention to them. "What do you mean?" he asked, sharply.

"The fairy's already here," Stiles explained. "It's not going to let us leave without a confrontation." He let go of Lydia's hand, moving his flashlight into his left hand so he could better grip the iron poker in his right.

"I wouldn't bother with that."

Stiles jolted in surprise at the unfamiliar voice, but before he could even turn toward it an unseen force wrapped itself around his forearm and twisted. Pain exploded in his wrist, and he cried out, eyes wide in horror. Something was grabbing him, an invisible hand clutching his arm in a vice-like grip, pulling it backward.

He spasmed, desperately trying to keep hold of the poker, but he knew he didn't stand a chance. The pressure was rising, and within seconds his grip slipped, the rod flying forcefully out of his hand to land somewhere in the trees to his right.

Instantly, the pressure vanished. Stiles staggered forward at the sudden loss of resistance, clutching his injured wrist in his left hand and hissing in pain. Well, this is off to a great start.

"Stiles?" Scott's voice was heavy with fear and concern.

Stiles winced, massaging the developing bruise on his wrist. "I'm okay." And he was – surprisingly. He gave it an experimental wiggle and, even though it was sore, it moved easily enough. Thank god for small mercies.

He raised his head, meeting Scott's worried gaze with a reassuring nod, then finally turned his attention back to his assailant.

The creature was humanoid, but that was where the similarities ended. Its slender figure towered over the glade, standing seven feet tall with arms that stretched down to his knees and feet too large for its body. It was bald, a broad forehead crowning an alien face with dark eyes and a sharp chin. Strange, dark green clothing clung to its body, and it had an odd, staggering gait as it walked to meet them.

Stiles instinctively shuffled to the left, moving his shoulder slightly in front of Lydia.

"We're not here to hurt you," Scott began, dragging his gaze away from Stiles to stare at the creature. He opened his hands in a universal gesture of peace. "We just want to talk, to find out why you're here. Maybe there's something we can do to help?"

The fairy tilted its head, beady eyes studying Scott up and down. "I doubt that," it sneered. "I have no interest in your kind."

"But you do have interest in innocent teenagers trying to have a romantic night out?" Malia spat, her eyes flaring blue.

The fairy was unimpressed. It eyed her with an expression that could only be described as disdain, and with a flick of its elongated wrist the air around Stiles suddenly thickened.

What the… Stiles automatically flailed his arm against the strange sensation, only to find that he couldn't. It was like he was surrounded by thick padding – a substance that wasn't hard enough to be painful, but firm enough to hold him in place.

His breathing quickened in panic. Frantically, he tried to move all four limbs, thrashing in every direction with all his strength. No matter how much he tried, he couldn't force his arms through the solidified air, his feet stuck to the ground like glue, and he couldn't even twist at the waist. The only thing he could move was his neck, and he desperately looked to the others for help, only to see that they were frozen solid as well.

His heart hammered against his ribs, so hard that it was starting to hurt, the sensation of heat increasing to a slow burn as it spread to his shoulders and neck. We've been in worse situations before, Stiles tried to reassure himself. Granted, he was having trouble thinking of one right this second, but surely there had been.

"You're not going to take us," Lydia cut through his thoughts, voice surprisingly steady. Stiles couldn't turn enough to see her, but he could hear shallow breathing that betrayed her nerves. "You said it yourself – you're not interested in our kind. And fairies don't tend to just kill people, so what exactly is your plan here?"

Stiles couldn't hold back a wince, but smoothed his expression when he saw the fairy looking in his direction. Lydia was smarter than this – she must have a plan - but still. Any plan that involved baiting the powerful creature holding them hostage couldn't possibly be a good one.

The fairy smirked, casually strolling forward before pausing in front of Malia. "You're right," it conceded. Stiles' arms prickled nervously, the burn spreading further down his arms and into his hands. It didn't sound worried in the slightest. "I'm not interested in you, little banshee. I'm also not going to let you draw me close enough to scream – at least, not without a gag."

The creature flicked its wrist once more, and Stiles heard a choking sound from behind him. He couldn't turn to see Lydia, but he could guess what had happened. Anger flowed through him and he clenched his jaw, glaring at the fairy as his fingers burned with intensity.

"Let her go," Stiles growled, the tone of his voice conveying the threat more effectively than words ever could. Malia snarled in support, and behind her Scott was burning holes through the fairy with crimson eyes.

The fairy didn't look remotely concerned. It did shift its gaze to Stiles, however, expression melting into curiosity as it slowly walked toward him.

"Now, this," it said, an undercurrent of awe in its tone, "this is interesting."

Stiles didn't think his panic could deepen but, apparently, he was wrong. His hand twitched nervously, the heat prickling his fingertips, and he set his jaw as the fairy approached.

Wait a minute. Confusion temporarily overrode his fear, and Stiles frowned as he tried to wiggle his fingers on his right hand. They responded easily, although he could still feel the solidified air holding the rest of him in place.

Could the fairy be losing control? It didn't seem likely. The creature didn't seem at all unsettled, its stance relaxed as it bore down on Stiles, beady eyes scanning his body.

Stiles would have squirmed, if he could move. He kept his fingers still, not wanting to reveal a potential weakness, and focussed on staring blandly at the fairy's face. He wracked his brains, trying to find a way that he could use this to his advantage.

His thoughts were interrupted by the fairy's smooth voice. "This town has been delightful, I'll admit. So many sparks, so much potential, I haven't seen anything like it in a long time. But you're different. How did you hide from me?"

Stiles frowned, exchanging a confused glance with Malia. The werecoyote shook her head, nonplussed, and behind her Scott looked equally lost.

"Uh, come again?" Stiles asked, baffled. "I think you're confusing me with someone else."

There was a glint of annoyance in the fairy's eyes and Stiles cringed internally as it rose to its full height, towering over him.

"I assure you I am not," the fairy replied. Stiles didn't think he was imagining a hint of anger in its voice. "A spark like yours should have called to me the moment I arrived here, but it didn't. Why is that?"

Frustration was rapidly overcoming his fear, and Stiles rolled his eyes in exasperation. "Are you deaf? I don't know what the hell you're talking about."

The fairy paused, stiffening, and despite its alien features Stiles was sure that it was glaring at him with rage.

Oops.

"Then let me be perfectly clear," the creature said, voice low and crisp. "You have a spark, a strong one. I know you can feel it; you must be able to. A smouldering flame burning through your limbs, pulsing through your veins, both strengthening you and consuming you."

Stiles' heart stopped.

The burn had been there on and off for a few days now. He hadn't given it a second thought, dismissing it as a physical manifestation of the anxiety that seemed to plague him constantly. It hadn't occurred to him that it could be anything more, but now that he thought about it…well. Anxiety was an old friend of his, but the burn was something new. The timing did seem to fit.

A wave of heat passed from his chest to his arms, and over his head lightning streaked across a clear night sky.

Oh.

Oh shit.

Stiles' heart restarted with a vengeance, pounding frantically in his chest in time with his rapid breaths. Malia was staring at Stiles with wide eyes and he exhaled through pursed lips, trying desperately to settle his rising fear.

Get a grip, Stiles. Find an anchor. Any anchor.

His mind whirled, thoughts scattering as the fairy stepped closer, lip curling to reveal a set of sharp, pointed teeth. It reached one hand out toward Stiles and gently trailed long fingers down his cheek.

"It's a curiosity," it said, voice silky smooth once more. "When you arrive in my world you will be well looked after, I assure you."

No. Oh, god no.

Panic rose in Stiles' chest, and before him he could see veins bulge in Scott's neck as the alpha let out a roar, shifting even as he was held immobile. He heard Lydia moan against her gag at the same time that Malia snarled, struggling against invisible bonds.

Realisation struck him, and his breath caught.

They wouldn't be able to save him this time.

The fairy traced a path down Stiles' cheek to his neck, before closing its fingers around his shoulder in a painfully tight grip, a determined gleam in its dark eyes.

In an instant, Stiles' panic broke.

Rage thundered through him, lightening cracking overhead as the heat grew to a fiery inferno, and suddenly Stiles was able to move. He wasted no time, smashing his left hand into the fairy's fingers and twisting out its grip in one swift move, leaping backwards at it hissed in pain.

"You dare," the fairy snarled, features contorting with anger, stalking closer to Stiles once more.

Stiles stumbled backward, keeping out of the creature's reach even as he glared ferociously in return. "Yes, I do!" he shouted, a roar of thunder emphasising his words. The fire burned through his chest, his arms, his legs, pulsing in time with his erratic heart, feeding his rage and feeding from it in return. "Let my friends go and leave. Now."

"You're a child," the fairy retorted, not cowed in the least. It made a strange gesture with its left hand and the air solidified once more, locking Stiles' legs in place.

Stiles thrashed, desperately trying to lift his feet, but they held fast. The creature closed in on him, reaching out once more with those long fingers, and Stiles didn't have time to think. The fire pulsed, and he moved.

His left arm lifted from his side, and out of the corner of his eye he saw a flash of metallic grey flying through the air before his fingers closed around a cool metal rod. The fairy leaned in, and Stiles brought the object to his front, thrusting upward with more force than he should have ordinarily been able to master.

The poker tore right through the fairy's chest, bursting out its back in a spray of dark green fluid.

The fairy's mouth opened in a silent scream. Stiles couldn't move, frozen in horror, as its terrified eyes locked onto his own. Warm blood poured from its chest, soaking Stiles' forearms, and its limbs jerked uncontrollably - once, twice, three times.

It lasted seconds, or minutes – Stiles couldn't tell, the moment stretching on into eternity. But, finally, it stopped. The creature's fear drained away, face slackening into a vacant stare, arms falling limp by its sides.

It didn't make a sound when it died.

Stiles stayed still, eyes locked onto the lifeless corpse before him. Vaguely, he was aware of raised voices nearby, hands pulling at him, trying to drag him away, but all he could see was the fairy – or was it a chimera? – begging for mercy with dark eyes, and suddenly he couldn't breathe.

The world spun. His chest constricted, fire blazing through his limbs, and a whirlwind of colours obscured his vision. The voices were louder, he thought, more panicked, but he couldn't make out the words over a crash of thunder. There was a high-pitched ringing in his ears, becoming more intense by the second, and he fell to the ground, digging his fingers into the dirt in a desperate attempt to ground himself.

The colours melted into white, the inferno burned hotter.

And then everything disappeared.