For a moment, the lab was dark as the void. The only illumination came from Sans' blue eye. Time stretched as every passing second felt like an age. Eventually, the computer rebooted and the cream glow of emergency lighting filled the room.

you always had a backup for everything, didn't you, gaster?

The kid was still there, rigid as a statue. He took a step forward. "Once, Sans. You saw the sun once."

Sans scoffed. "sure, buddy."

"Please. He made mistakes, but—"

"you know, this 'he' gag is getting really tired. who's 'he?' are you pinning this whole thing on some imaginary friend you concocted?"

"He isn't imaginary." The kid gripped the sweater over his chest. "Chara's here, with me."

"chara, huh? so you're white as snow, then? It was your hitchhiker chara that turned time into swiss cheese and ended all life five hundred times over? isn't that convenient."

"Sans, please listen to me. Chara walked the wrong path, but he isn't the same person anymore." The kid looked to the monitor. "That's all over. No more."

"as much as i want to believe that, the data trend says otherwise. this is all just act 1, scene 2806, of your cruel little play."

"You're wrong! The play is over, this is the happy end." He drew his hand from behind his back and held it palm up. "We're friends, Sans. You said so yourself. Please, put away the watch. Come back to the surface with me."

"friends, huh? i dunno, most friends don't keep world-ending secrets from each other. we might need to rethink our relationship."

Emotion began to strangle the kid's words. "Don't say that, Sans. Please, trust me just one more time. Forget all this and come count the stars with me."

Sans felt a great precipice yawning before him. He teetered on the brink with the choice. Finally, he shrugged his shoulders, shook his head, and smiled. "no deal, kiddo. you can't just bury what you've done. even if you're being honest, and you're not just playing me… your sins will never stop crawling on your back.

people always learn the truth, no matter how long it takes."

The kid's arm went limp and fell to his side. "He wasn't lying when he called you stubborn. You're worse than Asgore." He gritted his teeth and stifled a sob. "I'm sorry, Sans. It can't happen again. We're too close." He pulled a knife out from behind his back.

Sans eyed the dull gleam of the blade. "yeah, we definitely need to rethink that 'friend' thing."

Tears began to collect in the kid's eyelashes. He clamped the knife hilt in both hands. "I'm so sorry, Sans."

The kid's blue eyes disappeared beneath his eyelids, and he exhaled for a long second. His shoulders drooped and an indescribable fatigue seemed to soak into his features. When he opened his eyes, they were ruby red, and seemed to almost glow in the low light.

The kid looked around, half-dazed and finally settled on Sans. "I guess it was just wishful thinking, then." He blinked the tears out of his eyes and glanced down at the knife. His teeth sank into his lip and drew a pinprick of blood. It inched down his chin as he spoke. "He thought he could convince you in one try. He seemed to forget it took me over two thousand to ask you a single question."

Sans stuffed his fists into his pockets and leaned on the wall. "i get the feeling we've switched 'he's.' so you're chara, then? i'd shake your hand, but well…" He nodded towards the knife. "i'd rather go on living."

"He was so sure, too. That you would just let it all go; that we'd walk out of here together."

"happy to disappoint."

The kid grimaced. "I can feel him crying."

"a killer's tears aren't worth a while lot, bud."

"Don't call him that! He doesn't deserve that from you."

Sans straightened. "oh? then who does?"

"Me."

The child brandished the knife and lunged. He moved so fast his eyes left a red streak in Sans' vision.

Sans teleported across the room, more on instinct than reaction. He looked down, and a huge rend seemed to appear in his jacket. He hadn't even seen the kid swing. He prodded at the bone beneath and breathed hot relief.

"you're fast when you want to be."

The kid rolled his shoulders. "That always killed you in the hallway. I'm not what I used to be."

Sans let his eye burn, and launched a counter attack. A series of bone prisons materialized around the kid and stabbed inwards, to impale and crush.

The kid shifted and dove through each one, making a slow advance towards Sans all the while. "I knew you'd do this. You couldn't just be happy, like I begged."

"you've gotta see things from my side of the fence, bucko. for all i know, you were gonna kill me from the beginning."

"I didn't want this!"

The kid lunged a second time, but Sans was ready. He teleported back to the console and filled the room with blaster beams. As the kid dodged and rolled, Sans smashed out a command on the keyboard and a hidden doorway opened. He darted inside and punched the emergency lock. The door slammed shut just as the kid neared.

Sans braced himself against the door as his whole body heaved. He checked himself again, and saw a fresh slash in his coat. It was insane. The kid was so fast. He ripped off his jacket and threw it on the ground.

how many times has this all played out? how many times have i been fooled?

Sans stomped down the staircase and into the sub-lab. Maybe Gaster had left one last parting gift for him.

As expected, the kid hacked the override on the door lock in minutes. His footfalls echoed down the staircase like death bells.

Sans sifted through Gaster's forgotten inventions, searching for a miracle. They lined the dozens of tables and shelves that were scattered about the massive, rectangular room. Most were broken, or literal junk, but Sans held out hope for a portable DT extractor.

This had to end. They were all too close to the sun for the kid to ruin it again.

"I spent a lot of time down here." The kid emerged from the staircase and rested a hand on one of the tables. "Searching for spare parts to fix that scrap heap time machine upstairs."

The common ground brought a grim smirk to Sans' face. "at least there's one thing we can agree on."

The child began to weave through the maze-like tables. "Why didn't you just trust Frisk and walk away? We were so close."

Sans kept his eye locked on the kid, and continued to search with a blind hand. "dunno. maybe it was his tone of voice or his posture. it could have also been the knife he was holding behind his back. hard to say."

"I can't do this anymore, Sans. I haven't killed anyone in almost two hundred years."

"sorry, but i don't think there are any world records for 'longest time spent without killing someone.'"

The child drew closer and Sans retreated behind more tables.

"I know what you'll do. You'll tell them all. They'll come after me like you did, like Asgore did." The kid overturned a table to get closer to Sans. "I won't kill Mom or Pap again. I can't."

"i'm flattered you're willing to make an exception for me."

"If I MUST!"

The child leapt over a table and rushed at Sans.

Sans teleported back and used his magic to fill the air with scrap metal projectiles. The kid dodged, but took a blow to the head. He staggered back, and blood began to trickle from his brow.

Sans watched him bleed. "so you are human, after all. i had my doubts."

The kid dabbed at his forehead with his sweater sleeve. "You can call me demon if it makes you feel better."

"it has a nice ring to it."

The child steadied himself on a table and took a few steps towards Sans. "You once asked me to reset to square one. And I did, thinking all the while that I'd vanish. But I went through with it, for you and everyone else. It seemed worth it: to finally smash the cage I had built for myself and set you all free." The kid scowled. "But here we are. same cage, different shape. You're the jailor, Sans. You and the watch."

"most people get locked up for a reason, champ. all things considered, i think you probably deserve to do some hard time." He let his eyes fade out. "maybe even capital punishment."

"But what about Frisk!? Does he deserve punishment? He just wanted to share the world with you."

"maybe. the verdict's still out on that one. there's always some guilt by association when you're roomies with a mass murderer."

The kid snarled and advanced. "No more."

Sans sent another volley of scrap through the air, but the kid dove under a table. Sans tried to track him, but the kid was just gone. Sans teleported to a corner of the room to put his back against a wall. He tossed tables with his magic to try to flush the kid out of hiding.

The child's voice reached out from somewhere. It rebounded off the walls, making it impossible to pinpoint. "He spared me, Sans. After the lifetimes I stole from him, after all the blood I spilled with his hands, he spared me."

"can't say i'd do the same thing in his shoes…"

Sans scanned a nearby table and spotted a DT extractor. It was a charcoal-black piece of metal that vaguely resembled a gun. Two prongs protruded from where the muzzle should have been. Their razor tips glinted invitingly.

He inched towards it.

"I owe him. I owe him a life. He doesn't deserve to rot down here in this sin-prison that I constructed. You don't have the right to keep him here because of me."

"so, what then? just one more murder to hide all the others? after this it's nothing but sunshine and rainbows? what happens when they come looking for me?"

Sans took another step towards the extractor. A hand settled on his shoulder, and fear locked his joints. The kid was behind him, knife in hand. A sheath of tears covered his eyes and spilled out onto his cheeks. The glistening red matched the blood oozing from his forehead.

"Please… don't make me kill you."

Sans whispered through a half-breath. "that's entirely up to you, kid."

He tensed and gathered his magic to teleport.

The knife blow fell like a thunderbolt.