Archive of Our Own ^beta

Chapter Text

CRACK

The sickening sound rang out in Nightmare's acoustic meatus, followed by Killer's scream. Instantly distracted from the altercation with the positive guardian, his head whipped towards the sound. His eye caught Killer falling with Cross and Dust rushing to aid him. The king was caught off guard, unable to hide the concern he held for his henchman. Dream did not hold that same concern.

“Focus on me!” The guardian demanded swinging one of his blades towards the being that had killed his brother.

Nightmare dodged and released a low growl, ready to launch back into battle with Dream, just as Cross slid in to defend him. His blades caught against Dream’s, pushing the guardian back. 

“Boss!” The ex-soldier grunted. “Go check on Killer! His leg-” Cross’ focus was stolen from their conversation at a close swipe the guardian made, his boss was there and ready to defend him, using a tendril to retaliate quickly, sweeping Dream off his feet. Cross nodded to him in thanks, but Nightmare's focus had been readjusted. The king's fear for one of his own swiftly gutted him as he turned from his other subordinate. He moved across the field with purpose to find Dust defending a grounded Killer, while trying to keep Ink at a distance with his magic. In an instant, he swept down upon the creator, forcing him back substantially.

“Thanks, Boss.” Dust sighed, sweating from the effort to keep Ink at bay. Nightmare nodded and placed a hand on his subordinate's shoulder. 

“Can you keep him away for a little bit longer?” Nightmare asked, sorting through how long it would take to stabilise the injured sans. Dust nodded at his boss, and Nightmare left it to him. The king turned to his wounded sans, looking over him as his gaze fell to his left leg. His tibia fractured up to his patella, and Killer's fibula has been broken clean through. He sucks in a breath at the state of his henchman as he leans down beside him.

“Killer?” He questions quietly, to the sans who had clenched his eyes in pain.

“Hey, Boss.” He groans out his eyes barely opening to look at him. “Skittles got me good.”

“I can see that.” Nightmare stated plainly, his brow pinched as he scanned over Killer's leg for the best way to stabilise it. The spirit sends his tendrils over the injury, using his corruption to hold the break and fracture firmly in place. 

“RETURN TO THE CASTLE!” Nightmare boomed across the waterfall they were battling in. His tentacles comfortably supported Killer's weight as his men returned to him. Dust returned to his boss with Axe now in tow, who had, he assumed, subdued Swap. It took a moment for Cross to rendezvous with the rest of the team, Dream still in hot pursuit. With each of his men accounted for, Nightmare ripped a portal open through the codes of the pacifist swapfell and rushed everyone through. Though everyone was safe at home, the energy of the fight left his team rattled and fussing over their injured comrade, so rattled in fact that not even the ex-guardian noticed the new presence within his castle walls.

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Magic attacks flew across the wetland, accompanied by the sound of weapons clanging together. The groups that clashed were famous, of course, but they had never seen the bad guys in person. Let alone see them in a fight with the stars. Out-code or not, they tried to steer clear of the fights between guardians and gods. Tentatively, they peeked around the loud waterfall they had hidden behind, the skeleton with tar dripping down his face (was his name Killer?) was giggling. It was a mad sound like he wasn’t even fully there. He was facing off against Ink, who had Killer on the defensive. It wasn’t fair, god against a mortal like this. They traded Intense blows and taunting words, like a mortal battling the protector was a normal event.

“Whoa!” Tar Face yelled, dodging a stream of red paint attacks. His eyes narrowed in a way that didn’t match his tone. “You really going for the kill there, huh, Inky?” He added extra emphasis on his pun that had Ink’s eye switching to an exclamation point and swirl.

“That was a good one!” Ink called in response, what appeared to be a genuine grin on his face, as he halted his attacks for a moment. Tar Face took the opening and slashed forward at Ink. Who seamlessly dodged the attack with impressive flexibility.

“Cheap shot, man.” The protector pouted, resuming his offensive attack on the mortal. Their banter continued like that for a while till Ink seemed to get bored with the knife wielder's antics and disappeared into a puddle of his namesake. 

CRACK

They winced, ducking back behind their hiding place. A scream for the skeleton could be heard over the water. They weren’t sure who called out to him, no one from the stars for sure. Their voice was different, deeper, more aged by battle, not a voice they could maintain for long. They shook their head, peeking back out from behind the water. Tar skeleton had been grounded with a damaged leg, and a new one with a hood was above him now. A second new skeleton, dressed in black and white, was fleeing toward the dark guardian. 

It was his voice… They thought privately, cataloguing the information for later. They drew their attention back to the tar skeleton, where the hooded one was now trying to fight off Ink as well. He seemed worried… beyond what one would feel for a teammate. They could feel their head leaning to the side. Why would that be the case? The rumours around their team were nothing short of horrifying, from physical abuse to cannibalism. On the other hand, they had heard myths of the gang's rare moments of compassion, feeding Horrortale, and the team's clear functioning teamwork. A castle of a small, tight-knit group with resources to spare…

Curiosity overrode fear as they saw the way Nightmare himself fussed over one of the people he supposedly abused. They clutched the new device in their hand, glancing down at the screen, wondering if it could get them out of Nightmares' domain if things went bad. Gaze flicking to the now open portal, they acted on impulse, slipping behind Axe into Nightmares' castle.

The entire team followed closely behind Nightmare as he took Killer away from the living room, which looked like they’d been deposited in. They took a long look at the room around them, dazzled by the gothic aesthetic the castle held, before moving quickly to the staircase they saw in the corner of the room. They needed a home base within the castle to operate out of, best to find one while the team was distracted.

Chapter Text

Being injured was a drag. Not only did he cost them the fight, but now he had to deal with them all being worried about him. The boss had done an excellent job patching him up, as always, and then disappeared, leaving the target souled skeleton to face the other three.

“What were you thinking? Going up against Ink alone like that?” Cross shouted harshly. “You could’ve died.” Killer rolled his invisible eye-lights.

“Y’know, you say that every time I’m injured.” He snarked back, dismissing Cross’s concern. “Yet, here I am.” Cross scoffed, turning on a heel and exiting the infirmary. Killer watched him go with a sigh, flopping back against his cot.

“It was stupid.” Dust added, helpfully, from the right side of his bed. He rolled his head to the side, staring at the hooded skeleton blandly. Who stared back with a level of concern and care that made Killer's soul swirl.

“You guys were busy…” He supplied for explanation. Shifting the wrap on his leg that was covered in healing sigils. It would be healed in about two weeks, and until then, the boss would have him benched. His soul twitched at the thought, dreading the days of sitting around while the others picked up his slack. Dust shrugged at him.

“You still could’ve asked for backup.”
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Axe’s leg bounced under the table as he scanned over his inventory again. Nightmare had asked him to take a record of what they had after their retreat, but there should be more here. He stared at the count he’d done, it wasn’t right. It couldn’t be. It’d only been a few days since the mission, how were they so low on food? He barely noticed Killer enter the room. He leaned his crutch against the table, sitting next to Axe.

“Whacha’ workin on, Big guy?” He asked, glancing at the notebook on the table.

“Food inventory…” He rumbled, not tearing his eye away from his count. Blinking as the notebook was swept off the table into Killer’s hands. Who ran a finger down the list he had made.

“Why’re you staring at it?” He claimed as he reached the end of the page. “It looks fine to me.”

“You think it’s enough?” Killer quirked a brow at his question and snorted

“More than enough.” He said with a confident grin. “Any more and we’d be too fat to go on missions.” He joked, closing the notebook and pulling a smile from the large skeleton.

“You’re right, I spoil you,” Axe huffed, and Killer’s grin widened to something less snarky.

“I knew you could see reason.” He waved the notebook up in the air. “‘I’ll take this up for ya’, I wanna stretch my legs or… leg.” He said, standing from the table. Just as Cross walked by the dining room, a slice of chocolate cake in hand.

“Cross, can you…” Axe started as the soldier seemed to ignore him, walking right by without so much as a nod. “Uh… What was that?” He asked, turning to Killer, who groaned.

“Ugh, He’s still mad at me…” He explained, rubbing his face, and sitting back down. Axe blinked as the skeleton started complaining about the guard's recent attitude. The giant just shook his head fondly as he listened to Killer's complaints.
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Dust wouldn’t call himself a paranoid person, simply cautious, but right now, he felt like he was falling prey to paranoia. He couldn’t shake the feeling that something was wrong. Something in the castle shifted after their most recent mission, and he couldn’t place what. Not-Papyrus was insisting that his feeling was correct, and he should investigate, tear apart the castle if he had to. No amount of sleep or any of his other typical distractions was shaking the thought from his skull. He could ask Nightmare…

No, the boss had enough on his plate right now. He doubted Nightmare would want to take the time and energy to put to bed his childish idea, anyway. It didn’t make logical sense for someone to break into a castle that belonged to one of the most powerful beings in the multiverse. Dust just had to keep telling himself that, and eventually his paranoia would fade.

It had too.

Chapter Text

There were few times Nightmare was truly ‘busy’ with work. More often than not, he was just reading and trying to get a moment of quiet away from his crew, but today he was busy. Charts of materials and universe trajectories were strewn about his desk as he tried to rework his plans for the month without Killer. His broken leg was going to take weeks to heal, so for the time being, they were down a member. And…

The team's failed mission had set them back. 

No one was to blame, of course, but Nightmare couldn’t help but feel rather annoyed that his weeks of meticulous planning had gone to waste, and now they were down on negativity and resources. He pinched the bridge of his nose and sighed as he felt the rise of emotion coming from the kitchen downstairs. That had been happening more recently as well, and the king couldn’t place as to why. Killer’s ‘nice’ pair of shorts were gone, and he was convinced Dust had something to do with it. Meanwhile, Dust thought for sure that Killer had taken one of his many throw blankets. It took a thorough search of both their rooms to convince them that they had simply misplaced the items. The cherry on top was Axe’s food anxiety worsening. Between the failed mission and an unusual intake of food from his boys, their resident peacemaker was extremely worried that they would run out of food despite the king's constant reassurances.

He exited his office, heading down to his castle's kitchens to see what they were arguing about. A thud behind him had him pausing his descent as he reached the top of the stairs. Nightmares' head turned, scanning over the empty hall with a scrutinising gaze. His eyes-lights fell on a curtain that was swaying. He took a step toward the moving decor before a loud smash from downstairs drew his attention. He stepped into the kitchen quietly, finding Cross and Killer cleaning up a broken plate.

I should just get them paper plates. He groaned silently, his gaze falling on a disapproving Axe. Who had clearly made them clean up the mess they’d made.

“What happened, now?” He questioned to the room, tone a little more than annoyed, as he crossed his arms. Cross was eager to pipe up.

“He ate my chocolate cake. The slice that I had a fucking note on.” He claimed pointedly towards Killer, standing from the floor where the broken plate lay.

“But I didn’t!” Killer swore, also rising from the ground, “I saw you eatin’ it.”

“That doesn’t make sense! I know I hadn’t eaten that cake yet!” The soldier snapped, beginning to escalate into yelling again.

“Stop talking.” Nightmare demanded. His pair of recruits fell silent, He turned to Killer.

“Did you eat it?” He asked, probing his emotions for confirmation

“No.” The sans claimed firmly, completely sure of his answer. Nightmare turned to Cross.

“Is it possible you forgot eating it?” He asked, repeating the process.

“No, sir.” The guard stated, also completely sure of his statement. 

Nightmares' brow furrowed. How could that be? Dust had no real interest in sweets, let alone cake, and Axe took their food notes very seriously. He turned to the giant sans anyway, who gently shook his head before the spirit could ask. This was a puzzle indeed. Nightmare reached his magic out across the castle, searching thoroughly. He found Dust taking an afternoon nap, and the other three were in the room with him… So, who else was upstairs? He smirked rather suddenly, turning back to his boys.

“It appears we have an intruder.”
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They carefully closed the hatch to the attic before letting out a heavy sigh. The intruder stepped back away from the door. This whole arrangement was stressful, they decided, retreating back to the little pile of blankets and pillows they had collected. The pile was plush enough that they couldn’t feel the floor as they flopped into it. Rolling over to stare at the ceiling, they thought over the past few days.

The gang wasn’t at all what they had expected. They thought for sure that the gang would be more violent in the castle… They bickered a lot, sure, but they didn’t fight or hurt each other like everyone said they would. Axe cooked for them, none of them encouraged Dust's madness, Cross just wanted them all to stay safe, and Killer was funny and kinda… cool.

As for the guardian himself, they hadn’t seen much of him, outside of the king treating Killers' broken leg, but maybe he wasn’t as strong as everyone said? He hadn’t found them even when he had been less than ten feet from them. The stories were wrong about the gang. Why not Nightmare?

In all honesty, they hadn’t expected to get stuck here. Stay a few weeks, steal some food and bounce right? Wrong. The device they had nabbed wouldn’t work within the castle walls. They were stuck in his domain until the king himself let them out, but this was the best place they’d stayed in a long time. So why leave? It didn’t seem like the gang had any idea that there was an intruder in their home, and when they did start to catch on, they would just slip out through a portal the same way they got in. Having successfully rationalised staying in the castle, they drifted off for a nap.

They jumped, waking up just as a needle slid into their arm. They looked around, remembering where they were. It was rare that they slept soundly, guess today was no exception. Unsuccessful in falling back asleep, they crept out of the attic for a walk. They took a breath, feeling their magic swarm around them as they assumed Dust’s appearance. Their head went dizzy for a moment as they expanded themselves to their limit, before they began their walk. They went up and down different halls, still amazed that not only was the castle clean, but gorgeous. Other outcodes and multiverse travellers said the negative guardian had built this place himself. They wondered if that was true; the palace certainly matched his aesthetic.

They reached the kitchen without much fanfare. They weren’t looking for it; they had stocked up on plenty of food, but they didn’t want to get lost in the vast space. So they stayed in the places they knew. There were notes all over the fridge, stuff they needed, and stuff to remember. They wondered if these were Axe’s notes. Inside the fridge, there were more labels with names and expiration dates. The intruder hummed and shut the fridge, turning their attention to the counters where a few cookbooks were stacked. They reached out for the one on top of the stack, as a cleaver came down toward their arm.

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Axe’s quick motion made Cross jump; the person in their kitchen looked exactly like Dust. If said skeleton wasn’t standing right next to him, he would’ve been convinced that it was Dust. Axe didn’t seem to think that mattered. All he saw was a stranger in his home, stealing their food. The intruder moved in a blur of smoke(?) to dodge Axe’s attack, leaving his cleaver lodged in the countertop. They darted for the kitchen exit, and Cross moved into action, blocking their path and summoning his blades. The not-Dust skeleton made a hard left, moving past Cross in that same blur from earlier.

What was this sanses power?

He followed them, hot on the heels of the sans that had dared to break into their base. As they reached a corner, Cross summoned a wall of bones, cutting the sans off before he could make the turn. The intruder slipped as they tried to stop themselves. Their back hitting the castle's stone floors hard, Cross caught up with them in a matter of seconds. He hauled the, surprisingly light, sans up by the collar, slamming them hard into the wall.

“Who are you?!” He demanded, levelling a harsh glare at the breathless intruder. They didn’t respond, kicking out rather uselessly against the soldier, almost frantic in their motions.

Their face hardened for a moment, and just before Cross was going to repeat the question, their body phased out beneath his hands. He stumbled back as the black smoke moved around him before the intruder reappeared. Their body was smaller now and… human? He had never seen magic like that, and for a moment, he just stared at them. Their breath was heavy, and he could see sweat soaking their brow. Whatever power they were using, it was exhausting them. They took advantage of the guard's freeze and were already moving back down the hall toward the rest of the team. 

Nightmare, Dust, and Killer stood waiting just past the kitchen's entrance. Axe had already been following them down the hall, though he also seemed to freeze up at their change in appearance. They moved around the broken skeleton with ease, continuing to push toward the kitchen. Killer cut off Dust as he lunged for them. Determined to put a stop to the intruder. 

 “Killer, stop!” Axe’s voice echoed down the hall as he attempted to order their injured teammate to stay back.

He didn’t listen as his blade slashed toward the intruder. The now-human dodged the attack a little sloppily, bouncing off the wall before they steadied themselves. Killer's assault didn’t end there; he moved forward again, aiming for his opponent's neck. He barely missed his mark, nicking the side of their neck as they dodged and bobbed down to kick at his injured leg. Killer fell, and the Intruder took the opening. They tore his knife away from his hand by twisting his arm. Killer moved to try and tackle them from the ground, he pushed them into the wall with force and hit his head hard against the stone. Killer's body fell limp, and they all went still.

He wasn’t moving… but he wasn’t dusting either.

None of them were close enough to intervene, Cross realised with a start. If this stranger decided to kill him, that would be it. His brother friend would be gone, and no one was close enough to stop them. The Intruder stared at the limp body, the grip they had on Killer's knife tightening. Cross stepped forward without thinking. He just needed to be closer, he just needed to pull Killer from the line of fire. The human's head snapped up to him, like a deer in head lights, their gaze was wide for a beat, flicking back down the hall. Then it narrowed, they grabbed Killer's hood and yanked him up against them with a grunt, wrapping an arm around him to press the knife against his soul.

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The soul-gripping fear within the hall was suffocating. Each of his boys felt it the moment Killer stopped moving. Nightmare himself couldn't tell the difference between his fear and the others, as he stared at his fallen recruit in the hands of this shapeshifter. A possessive anger rose in his chest as his gaze met the intruders. How dare they. How dare they break into his home and threaten his men. He strode forward a few steps to get in front of Axe, pausing as they pressed the blade tighter to Killer's chest, his tendrils curling inward. The spirit's gaze narrowed as he studied the person who had Killer hostage. Their emotions told a different story from the look on their face; they were panicked and unsure. He could work with that.

“Try anything funny and I’ll… kill him.” They claimed, the false confidence in their tone didn’t do them any favours, considering the king could see right through them. His pride bristled at the threat to one of his own.

“You’re bluffing.” He snarled at the human. “You’re no killer.” They pressed the knife firmly against Killer’s soul, causing Killer's HP to drop a fraction. Nightmare's gaze flicked down to the soul, where the tip was now covered in liquid determination. His glare returned to the trickster as he bared his teeth at them. 

“I don’t want to be… Just let me out of here.” They pleaded, the underlying threat clear. The king's tentacles twitched with barely restrained rage, the edges sharpened and dulled as he considered his options. Risk their bluff, and by extension, Killer’s life or risk the location of his castle. Whoever they were, they didn’t seem interested in waiting for Nightmare to think through his decision.

“Just open a portal.” Their voice was more urgent now, betraying their true emotions. They knew if Nightmare decided that Killer’s life wasn’t worth it, their leverage would be gone, but so would his first henchmen. “Do it, and you’ll never see me again.” They promised.

Nightmare seethed in response. Each of his men stood near them, waiting for his order to guide them, and here he was so easily cowed by a low-life thief. Nightmare took a breath, resigning himself to his decision, just as Killer stirred. The portal swirled to life suddenly, causing the intruder to flinch back slightly. Their escape stood maybe four steps away from them, and they didn’t hesitate to dash for it.

Killer was quicker.

He launched himself forward, catching their knee and sending them to the floor. He pinned them to the ground swiftly. The force of the fall shook off whatever magic they were using to disguise themselves, leaving behind a black smoke-based monster with large white eyes. Unable to phase away, they struggled helplessly as Killer restrained their hands.

“No! I’m- SORRY! Let me go! Please!” They cried out under the king's right hand. Their voice was strange and echoey, despite not having a visible mouth on their face.

“Shut it. Brat.” He snapped above them. They let out a dry sob but didn’t say anything else. Nightmare let out a sigh of relief, closing the portal. It seems his team had also shaken off their previous apprehension, as Horror approached the pair. The giant paused, looking to Nightmare for orders.

“Take them to the dungeon.”

Chapter Text

Cross leaned awkwardly against the wall as Nightmare looked Killer over. Axe had taken off, dragging the smoke-based monster with him, who had gone oddly limp after Nightmares' order; they hadn’t even tried their little phase trick again. Leaving him woefully unsure of what to do now. His nerves were still fried from seeing the thief in the castle to begin with. How many of their interactions over the past few days had been with them? How long had they been in the castle??

He flashed a look over at Dust, who was staring impassively at the boss and Killer. If you didn’t know the guy, you’d think he didn’t care. The soldier was having trouble processing this. That monster could have picked them off one by one, could have sold out their location… but they didn't. He was pulled out of his thoughts as Nightmare finished looking Killer over.

“There doesn't appear to be any serious damage, but you will keep me posted if anything changes.” The boss delivered his verdict calmly.

“Yes, boss,” Killer replied with relief

“That kick should have spread the fracture.” Dust observed from the corner. “They avoided debilitating you further.” Cross blinked as he started the conversation about what to do with the trickster.

“Or they have bad aim~” Killer shot back, not interested in hearing excuses for the intruder.

“It was precise.” Cross corrected, “People don't just know how to do a take down like that. They were trained.” Adding to Dust’s point. Nightmare stared impassively between them.

“I have never seen magic like theirs.” The Boss stated calmly, returning his gaze to Killer, and using his tendrils to help lift him from the ground. “They could serve a purpose.”

Killers face scrunched, but he made no comment against their leader. Cross stared at Killer for a moment, he knew it didn’t feel great to be bested in front of the gang; he was probably holding a grudge.

“Whatever it is, it exhausts them.” He supplied. “And changing their appearance quickly seems to drain them more than it does to hold one form.” Cross looked to Nightmare as he spoke, watching as the king put a hand to his chin in consideration. Axe lumbered back upstairs a moment later.

“They’ve been secured…” Axe says, nodding to the boss, respectfully.

“They try anything?” Dust asked, looking the giant over. Axe shook his head. “Did ya’ check them?” Axe nodded.

“Said they were LV 3, and they were sorry about Killer.” He shrugged. Nightmare hummed, in a noncommittal manner, and turned away from them.

“Refrain from feeding them for now, " he ordered the group. Axe sucked in a breath. “No more than two days, Axe. I simply wish to conduct some research on this new kind of magic. Shapeshifters have been a thing of fiction until today. Dust, would you assist me in my research?”

“Of course, boss.” Dust said flatly, falling into step with their king as he retreated to his library. Cross heard Killer scoff beside him, the tar leaking skeleton turning on his heel. *He’ll cool off eventually…* Cross thought as he left him alone in the hall with Axe.

“Ya’ wanna help with dinner?” Axe asked the ex-guard, brow quirked.

The flow of cooking under Axe’s orders was easy. It helped him keep his head on straight, get his thoughts in order. Why’d they break in here? He slowed his chopping for a moment before blinking and continuing the task at hand. Had the others noticed how small they were? He yanked his hand back before the blade could nick his phalanges.

“Careful.” Axe rumbled next to him. He mumbled an apology before he continued to quarter the pile of potatoes the other had assigned to him. He worked his way through the stack, and Axe had moved him to stirring some kind of broth, away from anything sharp, he noted. The soldier’s eye lights flicked up, meeting Axe’s gaze.

“Is that all their check said?” he questioned abruptly, catching the giant off guard, who blinked at him before responding.

“Yeah, why?” Axe asked in return, and Cross sighed, giving him a half-hearted shrug.

“I dunno, I’m just curious about… something” Cross trailed off and continued stirring.

“Shoot,” Axe said, setting a timer for the chicken he’d put in the oven.

“I,” He hesitated, “was wondering how old they were…” He looked from his stirring, his thoughts from the last hour now escaping him. “I mean, I know size isn’t really indicative of age for us, but didn’t they seem young? And who doesn’t know not to mess with Nightmare’s people at this point? It just doesn’t make sense.”

Axe listened patiently as he rambled on. He’d moved on to washing green beans now, but was still clearly listening to the soldier. A beat after Cross finished, he spoke up.

“They’re very afraid.” He stated, not looking up from the veggies. Cross flashed him a confused look.

“They’re being held prisoner, of course, they're afraid.” Axe shook his head.

“Not of us.” He muttered down to the sink, his gaze pinched.
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Dust pulled a book off the shelf, blowing the dust, heh, off it. ‘Trickster Creatures in Mythology’ He raised a brow, flipping the book open to see Nightmares' fancy cursive marking the book from Flowerfell. He tucked the book under his arm, continuing down the shelf for more that could be a record of shape-shifting magic. The hooded skeleton grabbed three more books before settling into the library sitting room next to the boss. He peeled each book open, scanning the index for mention of shapeshifting. He made his way through each of them, not finding much outside of the odd fae creature. He truly didn’t feel like trying to find more relevant books in the king's vast collection; they’d been here for hours, and he was still a sans after all not-papyrus was also always quiet when he was with Nightmare. None of the creatures he found seemed to have the same level of control that the runt had, anyway.

Beside him, the boss snapped his book shut, standing with a frustrated sigh. Dust didn’t look up as he passed him, headed towards the far shelf he’d retrieved the book. It didn’t seem like Nightmare was having much luck either. The king’s affinity for physical research was lost on Dust. Personally, nothing felt more rewarding than hours of work at a screen paying off, but the boss was different, older. He wasn’t sure Nightmare would understand a computer, even if the gang could have them. So they researched through books and folders. The boss returned with one of the binders that they used to categorise said folders. He flipped through it rather impatiently before closing the binder entirely.

“It’s strange.” He stated staring at the coffee table when the binder rested. “All my years, my entire collection of knowledge, and I’ve never encountered a creature with this power. What do you make of them?” He asked, turning to Dust.

“Don’t have much to go off.” Dust deadpanned. “We should ask Error.” Nightmare shook his head

“It’ll take too long to convince him to help us.” The boss sighed, pinching the bridge of his nose. “Perhaps it would be best to simply let Killer have them.”

“Don’t do that.” Dust cautioned. “A power like this can be used… If they don’t work for the Omega timeline.” He paused, contemplating for a moment. “You said they were in the attic?” Nightmare nodded.

The array of items they’d collected was now spread out on the library floor. The food they had been missing was there, which made sense, along with his blanket and a small drawstring pouch. The bag didn’t have much: a broken watch, a small utility blade, a set of keys, and… an Omega timeline door key. The tool that most of the safe havens' people used to hop universes. Dust watched his boss’ tendrils twitch, his face resigned to try and hide his obvious rage. The Omega timeline had tried to make its way into their base.

“That certainly changes things…” Dust murmured, staring at the device he’d dumped on the floor.

“See if the location of the Omega timeline is on there.” He gritted out. “I’m going to get some answers.” The boss whipped around, melting through the shadows.
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There was no light down here. They had gotten so used to seeing the light… They tried to focus on anything else, the cuffs held tight around their wrists, attached to long, heavy chains keeping them bound to the wall. The cuffs had to be charmed or something, because try as they might, they couldn’t shift their form to escape their bindings. They had tried yanking on the chains, but it only served to exhaust them. Leaving them sitting on the ground, knees brought up to their chest in the farthest corner from the door. The air felt thick, and every passing moment, they felt like it got a little harder to breathe.

They never should have come here. No amount of free food was worth this. Nightmare was going to kill them, probably torture them first. To think they thought anything different about the king of negativity and despair proved that they had this coming. They shook their head, they didn’t want to think about that either. There was nothing down here but them, it seemed. At least they would die somewhere clean, they guessed, as the ground wasn’t covered in dirt or monster dust. They shifted themselves to lean against the wall, counting the bricks along the surface till they hit the door, then they’d start the next row. Like counting sheep. They mused to themself, maybe they’d fall asleep and Nightmare would take some pity on them. They gulped and started counting the next line. Waiting for whatever the king decided their fate to be.

Chapter Text

Nightmare stood silently above the being that had dared break into his castle. They had slumped against the wall of their cell, asleep. He’d observed them briefly before they’d fallen asleep. They had been staring at the wall, picking at their wrists where the cuffs were seated. Deep bruised marks were visible around the cuffs as well. They were wearing Killer’s shorts, he noted, one shoe conspicuously missing. He narrowed his eye down at them, silently cracking the cell door open. He stepped into the cell and slammed the door, jolting the intruder awake. Their head snapped up with a gasp, eyes large as they stared at the king, pressing themselves impossibly closer to the wall. Their body seemed to shift rapidly before being held solid by the charmed cuffs.

“You’re not going to escape that easily,” He started with disdain. “If they truly thought you would be enough, you get past my defences, then they’re desperate.” Their small form shook with fear as they narrowed their brow at him. Their plain confusion filled Nightmares' senses, as their pupil-less eyes seemed to flick downward.

“You went through my stuff.” They realised meeting Nightmare's eye once more. The king's venomous glare had them trembling as a tendril shot out, yanking them off the ground by their arm. They yelped, flailing wildly as they were lifted off the ground and pulled much closer to the king. The smoke that made up their body thinned again; whatever magic that allowed them to phase was clearly instinctual.

“You don’t have stuff anymore, spy,” He hissed into their face. “Your belongings, your magic, your very soul was forfeited the moment you stepped into my castle.” A small whimper escaped them as they twisted their head to the side, pressing their chin into their shoulder and squeezing their eyes shut. 

“And if you want your death to be a painless one, you’ll tell me what your mission was.” The ex-guardian snarled, enjoying the snack that their spiked dread and anxiety gave him. Their eyes shot open, their head shaking slightly as they opened their mouth to speak. The shifter's jaw trembling too much to form any words for a moment.

“I- Ther- There’s, please- I-” They stammered pathetically. The king scoffed, tossing them back to their feet. They stumbled, leaning up against the wall to stay on their feet. The shapeshifter rubbed the part of their arm that he had grabbed, taking shuddering breaths to steady themselves.

“Well?” He questioned, holding no sympathy for the trickster in his dungeon. “Spit it out.”

“I don’t work for them.” They stressed looking up at Nightmare, and a taste of desperation flowed from them. Desperate to be believed, or understood, he wasn’t sure.

“There’s no mission,” they continued, hanging their head. “Please, you have to believe me.” He narrowed his gaze at them in scrutiny, and they took his silence as a sign to keep going. “I’m so sorry about Killer. I didn’t mean for him to get hurt, I just wanted-”

“Shut up.” Their mouth snapped closed. “Say, I believe you. Why do you have one of the Omega Timeline's keys?” He demanded stepping closer to the small smoke monster.

“I stole it from one of their scouts.” They explained, flinching back from Nightmare, clearly craving distance from him. The lack of anxiety behind their story left the king inclined to believe them. “They left it on a cafe table while they were in the bathroom. I don’t think they even know I exist…” They trailed off, and Nightmare was taken aback by the amount of despair that came with the statement. He shook off his surprise, keeping his tendrils curling passively behind him.

“So you came here of your own accord?” They nodded, swiftly. “Why?” He growled to them, leaning down and crowding further into their space.

“I- I don't know? You have food, and there’s not a lot of people here, it seemed safe enough.” They muttered, picking at the bottom of their shirt. Nightmare pulled back, raising a brow at them. Looking at their form a little more closely, he had assumed their size was a choice or perhaps due to the clear malnourishment they faced, but something about that reasoning felt impulsive, even juvenile…

“How old are you?” The question left him before he could stop it, and it got the intruder to look up at him again. No longer awkwardly avoiding making eye contact. They were quiet, taking the longest to answer such a simple question.

“I’m…” Their fidgeting halted, eyes flicking nervously. Nightmares' tendrils tensed, ready to react to the lie building on their tongue. “I… just turned nine…” They whispered the truth quietly, so quietly that the king had a hard time making out what exactly they’d answered. He blinked down at them, their hands were tearing a new hole in their shirt, their eyes, which were too large for their face, made nervous eye contact with him, like a kid fessing up to a lie. His eye widened slightly, without the stripes that marked most monster children he assumed they’d outgrown them, even if it turned out they were young. Not that they weren’t even at double digits.

“You truly are nothing but a child.” He realised slowly. “Who’s taking care of you?” He asked cautiously. Their eyes narrowed up at him before they shrugged. 

“I take care of myself.” They muttered noncommittally. Nightmare scoffed, and something akin to a glare passed over their face. He couldn’t imagine a child being any good at taking care of themselves. Their appearance only seemed to prove his point, the ability to steal anything they wanted or needed, and they ended up in tattered clothes, malnourished, with almost nothing to their name.

“I do!” They insisted, raising their voice. “It’s easy to steal when you can do what I can! And when people catch on, I hop worlds.” He was indifferent to their anger. Casting a stare that had them shrinking back into the wall.

“That’s quite the life. How long have you been doing this?” He hummed, a curiosity bubbling in the back of his mind, in regards to the young intruder. Nightmare was never one to take risks; he needed more information to approve his idea. The child's confusion was clear as they looked at him, he tilted his head, flicking a tendril towards them in subtle threat. They got the gist, flinching away.

“Since I was six…” They answered quietly. Nightmare stilled for a moment, and they stiffened in return. His gaze moved over them before his motion returned. Their situation felt familiar to him, struck a certain chord, he supposed.

“Something happened to your parents?” He questioned, and they shook their head. “No?” He raised his brow. Not having parents wasn’t exactly rare in the multiverse, but most children had some kind of guardian. Babybones Sanses and Papyrus’s had Gasters, Monster Kids had Undyne, etc. Based on their appearance, perhaps a Grilby?

“I never met my parents.” They murmured, looking down at their feet. Their emotions had settled into a tense nervousness that seemed to escalate to something closer to panic when they looked at him.

“So who took care of you, for those six years?” He pressed, shock ran through the prisoner, and for the first time, they looked up at him with defiance.

“Why do you wanna know?” They asked, hands curling at their sides. “Aren’t you going to kill me?” It seemed their patience was running thin, but Nightmare wasn’t in the mood to gently remind them of proper respect. His tendrils lashed aggressively, as he stabbed one through the stone wall. They stumbled back into the corner, their fear rising as he glared down at them.

“I’m not in the habit of killing children.” He claimed. “But there’s really no line I won’t cross.” He continued, his voice bordering on a growl. “And right now, you’re on the wrong side of that line.” They shrank back further, eyeing the tendril lodged in the wall.

“So if you want to earn your life back, little one.” His voice went sweet again as he ripped his appendage from the wall, cracking the bricks, and causing rubble to cascade downwards and bounce off the floor.

“You’ll answer any and all questions I have for you,” he snapped. They gulped and nodded a little frantically. “Good.” They were silent for a beat till Nightmare raised a brow at them. They blinked, though when they did, their eye closed vertically. Nightmare resisted the urge to make a face as they realised what he wanted.

“Scientists.” They muttered. “In this big lab complex, with other experiments.” Nightmare could feel their discomfort around the topic, but he needed to know where exactly this magical marvel came from.

“And you were one of these experiments?” Nightmare asked, crossing his arms. They nodded, returning to their picking habit to calm their raised nerves. He tilted his head in consideration once more. “Perhaps a prized experiment?”

“I don’t know…” They answered truthfully, “We were all kinda treated the same.” He narrowed his eyes down at them, and they swallowed hard, but their hands never stopped moving, so he brushed it off as nerves.

“We?” He pushed. “The other experiments were alive? How many were there?” Their hands tightened into fists for a moment. Defiance and anger bubbling through the terror, swiftly those emotions were bottled and suppressed to give the king his answer.

“I never counted.” They returned, tugging on a loose thread. “More than ten?” It was the best answer they could give him. “I don’t think any of them made it out alive…” They muttered mostly to themselves.

“How did you escape? Assuming they didn’t let you go.” Their mouth pulled into a hard line at the question, smoke flickering and shifting once more. As their hesitance returned, the king questioned if they were worth the trouble, but before he could entertain the thought, the intruder was answering. It seems his threat had stuck.

“I… I’m not sure what happened…” They started softly. “They’d all been working on- on this massive project. Then one day, alarms started blasting, and the lock on my door failed. So, I left disguised as a doctor, there was so much chaos and panic that no one noticed me. But I went through this weird door, an-and I ended up in a different universe.”

Nightmare raised a brow at that. One of the Omega timelines' doors? Core frisk wasn’t usually one to condone experimentation. Were they truly turning to such depraved methods to overpower him and Error? He would need to conduct further research, as the child's knowledge appeared to be limited. Until then, it seemed his enemy had provided him with a very interesting opportunity. He turned his attention back to his prisoner, whose fidgeting had increased since he stopped talking to them.

“It's a shame, really,” He cooed toward them. They stiffened, staring up at him wide-eyed. “Someone your age, out there all by themselves… No one to take care of you. No purpose, just survival.” He shook his head as if crestfallen at the idea. They swallowed, shuffling in place as they shrugged.

“So?” The shifter questioned their caution rising as equally as fear, though they didn’t show it. He tilted his head slightly, so they could keep it together when they wanted to. Good.

“Well, the Omega timeline is supposed to help, poor souls like you.” Their eyes narrowed. “They could have saved you sooner… could have saved the other *experiments* as well. Instead of aiding the people, experimenting on children.” A hurt rage rose from the child before him.

“What?” 

Oh, this was too easy.

He raised a brow to them. “Well, those universal doors, you mentioned, are only used by the Omega timeline,” the slow shock on the shifter's face had Nightmare fighting a smirk. “They were there that day.” 

He let silence fall over the room for a long beat. Letting the implications sink in a little. To their credit, almost none of it showed. Their face was pinched, their hands still, but they didn’t cry or yell; they simply seemed to accept it. Dust had been right. They were far too good to waste.

“You want to walk out of here alive?” He asked, breaking the silence. A hopeful nod quickly answered the question. He smirked and let out an amused huff that had them shrinking back.

“Alright. How about a deal then, little shapeshifter?” He inquired, summoning the key for the cuffs to his hand. Their eyes found it immediately.

“What kind of deal?” They wisely questioned in return, and the ex-guardian couldn’t fault them for that.

“You receive training, food, security, and a warm bed at night.” He offered, ignoring their narrowed gaze. “In return, you work for me. On my team, spreading terror across the multiverse.” He extended a hand to them. They stared at it, then at him, then at the key. Conflicted.

“I could just kill you. Or let my men kill you.” He supplied revelling in their fear-ridden flinch. “I’m giving you an out and a purpose.” They swallowed. “Play your cards right, and we could get revenge for all the experiments that didn’t make it out of those labs.”

Their face was tight for a moment, their eyes falling once more to his hand. They took a deep breath before their chains rattled. Their hand raised to meet his in a sealing handshake.

“Deal.” They breathed like it was a secret or awful fate. Perhaps to some it was, but to the king it was assured victory.

“Excellent.” He purred as they pulled their hand back from him, holding their wrists out to be unlocked. There were, in fact, uncomfortable-looking bruises around their wrists, undoubtedly from their futile escape attempts. He hummed before releasing the hands.

“You got a name, kid?” He asked, approaching the cell door.

“It’s Mirage.” They said with a nod, and Nightmare raised a brow.

“Huh,” He looked them up and down, a trickster shapeshifter who didn’t stay in one place long. “Fitting.” He commented.

“Well then, Mirage, welcome to the team.”