Timeline: Season/series 4, post 'Aithusa.'
Tags/Warnings: Hurt!Merlin, Torture, Protective!Arthur, Magic!Reveal, general creepiness, and fluff.
Update 2018: Thank you for all of the great support and feedback! I was nervous venturing from my ride-or-die fandom but everyone has been so amazing. I more-or-less re-wrote this whole story because I felt like there was so much more to tell, and while I was editing my plot bunny came back for revenge. Whether you're reading this for the first or second time, I appreciate it and I hope you enjoy!
Ignis Fatuus
n: Latin, "Foolish fire;" A deceptive goal or hope.
Merlin wakes to a burning in his shoulders that could rival fire. Blinking away the heaviness from his eyes, he finds out why: his wrists are locked in heavy shackles anchored to the cave ceiling, pulling his arms tight enough to lift his heels from the ground. Merlin can feel the magic pulsing in the cave and flowing through his restraints. Cautiously, he reaches out with his own magic, gently probing the darker energy. The magic surrounding the metal is strong but Merlin can tell that his is stronger.
"Merlin, wake up."
Arthur's voice pulls his attention away from the bonds. Across the cave, Arthur's wrists are in identical shackles, with his arms spread out and secured to the cave walls. Despite their predicament, Merlin's relieved that Arthur isn't strung up like he is, tearing his arms from the joints and struggling to breathe.
"I am awake," Merlin croaks.
Arthur's eyes narrow, hearing the pain in his servant's voice, but any response the king may have is interrupted by the appearance of their captor. The towering, dark figure glides into Merlin's vision, drawing close enough that he expects to feel the monster's breath on his face. He pulls back as far as the manacles will let him.
Merlin doesn't know what to call it. They were captured before he could return to Gaius to find out more about the creature that has been stalking him for weeks. The shape and movements of the entity could pass as a man, but the corpse-like features of its face make it undeniably evil. Most of its features are indistinguishable, except for its wide human-like mouth, sharp jaw, and glowing eyes. The skin that he can see is insect-like: tight, thin, and near translucent in color. The wraith stands a full head taller than Merlin, even with his body stretched impossibly far in his chains. It stares down at him with narrowed, cloudy eyes.
"Confess."
Merlin knows what it wants and it's the one thing he will never give, no matter the consequences.
The sorcerer swallows and whispers, "Never," praying that Arthur doesn't hear it.
The wraith's mouth twitches, looking pleased as if it had been hoping for that answer. Slowly, it reaches into it's tattered robes and pulls out a long, curved dagger from the folds.
Merlin tracks the movement and lands his eyes on the blade. It really isn't the dagger that scares him, nor is it the dead, white eyes of the creature that's holding it - it's knowing that he's going to die with Arthur knowing what he is, and he won't get the chance to explain.
"Confess."
Within the tight confines of his bonds, Merlin shakes his head 'No.'
The wraith is slow at first, caressing his skin with the blade as if introducing him to it. The knife is sharp and precise enough that the sting of pain doesn't come until the edge leaves his skin. The initial contact makes him gasp but he quickly presses his lips together, telling himself that he won't give it the satisfaction, or cause Arthur more pain than necessary by making a sound.
With the knife temporarily at the wraith's side, Merlin drops his head back and tries to force more air into his chest. The torturous feeling of his lungs struggling to expand under his ribcage may kill him before the creature can get its confession.
"Confess." Blood drips from the knife, landing on the stones at Merlin's feet with a sick sound.
"I have nothing to confess," Merlin says as he stares into the black void under the creature's hood.
Without a sound, the wraith raises the dagger once more. The sharp edge pushes against Merlin's clavicle, deeper this time, gliding in a diagonal line underneath his collarbone. Merlin bites his lip hard and refuses to so much as groan.
"Confess."
Across the cave, Arthur growls, "Whatever it is you want from him, he doesn't have it. He's a only a servant."
Merlin can hear Arthur struggling against his bonds, cursing through clenched teeth when it gets him nowhere. Merlin closes his eyes and tries to focus on the pain, on staying in the present. If he focuses on Arthur it might make him do something stupid, like cry or plead for Arthur to get them out of this.
The next strike takes him by surprise. The knife makes a long, vertical cut down his torso, crisscrossing the previous laceration and ending before his navel. It's deep, and he can't stop the short, pain-filled shout from escaping his throat.
"Merlin!" Arthur yells.
"Confess."
Blood begins to trickle down his torso, soaking into the waistband of his trousers, making his skin itch.
"I will confess to nothing," Merlin spits out.
The wraith seems amused by his defiance as it pauses to consider him. It steps impossibly closer and hisses, "You will," with so much conviction and pleasure that it makes Merlin shiver.
Merlin tries to ignore how unnerved he feels by the proximity of the wraith as he tightens his jaw and says, "I will never tell you anything."
"Merlin, shut up," Arthur demands from behind them, "Stop trying to be a hero."
The wraith reaches out a bony hand and wraps it around Merlin's throat, but it doesn't squeeze. Instead, it puts just enough pressure on his windpipe to remind him of how easy it would be to crush him.
"Confess."
Merlin grits his teeth in disgust, feeling the leathery texture of its fingers against his skin, "No."
Enraged by Merlin's refusal, the wraith circles around him and brings the knife up the length of Merlin's back in one swift, furious stroke, cutting deeper than any of the previous wounds. The scream that comes out is unintentional but Merlin still tries to bite it down, hyper-aware of the fact that Arthur is watching him.
"Bastard," Arthur growls, "Let him go! He knows nothing!"
Merlin spits the saliva that's built up in his mouth, "Arthur, please…"
Arthur doesn't even know what the wraith wants from him, hasn't even tried to guess. As far as Arthur knows, this is just another thing that's happened to them, another life-or-death situation that they'll somehow find their way out of. Arthur has no idea that this is all Merlin's doing, and the guilt is almost as painful as his bleeding wounds.
The wraith first showed itself in Merlin's dreams, haunting him, showing him visions of Uther dying and Morgana laughing. Days later it was in the market, stalking him from behind carts, passing around people unknowingly, like a spirit. At first, Merlin thought he had been seeing things - just fleeting shadows out of the corner of his eye. But soon it became bolder, showing it's full form and venturing closer, and Merlin couldn't deny it any longer. Before he could work a solution out with Gaius, Arthur demanded that they go on a solo hunting trip to, "Relax." They were ambushed in the woods when they stopped to make camp. The thing was so fast, Arthur barely had time to draw his sword before they were both incapacitated.
"Confess."
Merlin takes a few breaths and looks Arthur in the eye for the first time since this started. For the moment Arthur is safe and Merlin is going to make sure he stays that way. Arthur must see the resolve on his face because he shakes his head in frustration, and begins pulling on his restraints with renewed vigor.
"I have nothing to confess to," Merlin finally says.
The wraith is vibrating with rage and Merlin prepares himself for the next attack, but it doesn't come. Instead, the creature takes the dagger, still slick with blood, and approaches one of the torches illuminating the cave. Then, it slowly brings the knife up to the torch and holds it over the open fire.
Merlin's throat bobs. He knows what's coming.
"No!" Arthur shouts, the panic in his voice bounces off the stone, "Take me! Take me, he can't help you!"
"Arthur, it's going to be alright," Merlin says, his voice hitching. His lungs feel like they're caving in, and it's only made worse by his rapidly increasing fear. He can't take his eyes off the knife, steadily glowing brighter as it becomes hotter.
The wraith moves from the torch and pulls out the glowing blade. Despite the reassurance he gave to Arthur, Merlin is terrified of what's coming. The creature leers at him, drawing closer and closer. Merlin's feet scramble on the cave floor, trying to find purchase to flee, but the shackles don't budge.
The monster stops in front of him, brand in hand, offering Merlin one last chance to save himself. Merlin can see the glint of sharp, animal-like teeth as it grins at him from behind the knife.
"Confess."
He wants to, god does he want to, but he won't. There's one thing that will hurt him more than fire, more than steel, and it's the look of hatred that he knows he'll see in Arthur's eyes if he ever finds out what he really is. His destiny is with Arthur, and no amount of pain is going to take it from him, not as long as he can withstand it.
So Merlin swallows, looks it in the eye, and says, "No."
The wraith steps behind him, by design, Merlin is sure, so Arthur can see his face when the hot blade touches his skin. It grabs his shoulder with one hand, holding him in place with a punishing grip.
"Merlin, look at me," Arthur demands.
Merlin opens his eyes, not even realizing that they were closed. He can feel the heat crawling closer to his skin, and he has to force himself to keep breathing.
"Look at me. It's going to be alright," Arthur says, his face a complete mask of bravery, trying to stay strong so Merlin will as well.
Nothing can stop the inhuman scream that tears from him when the scalding hot metal presses into the small of his back. He can hear Arthur yelling but he doesn't know what he's saying, if he's even saying anything at all. There's nothing but agony and fire, and it seems to last forever until finally, the blade is removed. Merlin's body quakes; he wants nothing more than to collapse on the cold cave floor and never wake up. He knows it's bad because what was once excruciating pain is now dulling into numbness.
"Confess."
"No." A string of saliva escapes his mouth as his head hangs down over his chest. Merlin struggles to push down the vomit that's threatening to come up.
The wraith pulls away and smoothly walks back to the torch, re-heating the blade that's still impossibly hot. It stares at him as if it's happy to be doing it.
"Please," Merlin begs, swallowing down the sobs that want to escape, "Please don't do this, please."
The wraith doesn't react, just continues to let the blade heat up to an absolutely punishing temperature.
He can't hold back the tears any longer but his struggling lungs refuse to let him weep in earnest. If he wasn't so scared he'd be absolutely humiliated over the fact that he's losing it in front of Arthur, but right now all he can think about is the pain that he knows is coming.
"Merlin, listen to me," Arthur pleads, "Just tell it. Whatever it is, just give it what it wants." Arthur sounds positively wrecked like he's hurting just as much as Merlin is.
If only it could be that easy. It's all he's ever wanted, to tell Arthur and to be accepted. To be able to tell Arthur everything he's done, the good and the bad, to explain that his entire existence relies upon staying by his side. But after what happened with Uther's death only a month ago, Merlin knows that it can never happen. Arthur hates magic now more than ever.
So he's going to let the monster hurt him, no matter what the cost, no matter how long it lasts.
"I can't, Arthur," Merlin sobs, "I'm sorry."
The wraith moves away from the fire, pulsing hot blade in hand. Merlin whimpers as it draws near, too weak to try and push away. The creature reaches out with a skeletal hand and clenches Merlin's jaw with bruising strength.
"Confess."
Merlin's terrified, he can feel his magic bubbling up, aching to lash out and prevent the assault. He stomps it down, pushing it to a place that's less threatening. It calms for the moment but Merlin has no idea if he's going to be able to keep it in place through the next round of torture.
It's hard, it's so much harder than anything he's ever done before, but he says, "No."
With a sneer, the creature turns from him and stalks over to where Arthur's being restrained. Unadulterated panic fills Merlin's body, making every nerve ending sing with adrenaline.
"No!" Merlin shouts, "Don't! It's supposed to be me!"
The creature grabs the opening of Arthur's tunic and rips it open. Arthur's chest is heaving but he's silent, jaw tight and eyes forward. The creature grabs a handful of Arthur's hair and yanks his head back and hisses, "Confess."
"Let him go," Merlin commands, "It's me you want. Don't touch him."
It smiles widely, knowing that it's finally found the one thing that is able to weaken the sorcerer. Merlin's stomach turns over as the glowing orange blade moves closer to the exposed skin on Arthur's torso.
His magic is positively screaming, unable to withstand the thought of Arthur being hurt, of failing to keep Arthur safe. He knows the consequences but he won't be able to live with himself if Arthur gets tortured because of him. Not if he can stop it.
He lets his magic go. It explodes from him like a storm: loud, bright, and powerful. The black cave is encased in blinding white light that swallows the creature whole. Arthur turns his face into his shoulder, blocking out the worst of it. It lasts until Merlin is spent, exhausted from pain and trauma. The light fades slowly and when it's gone, the creature is too. The last thing Merlin sees before he passes out is the shock on Arthur's face.