Author's Note: This story refers to Did-You-Reboot's version of GLaDOS, Chell, and RM. You should see her tumblr or askinsanewheatley's tumblr if you don't know who RM is or are confused about anything. This fic was made for my lovely and awesome sis! You can visit HER tumblr under her name, Yoruna. X3

Love ya, sis!

He hated it.

Watching from a distance, they walked arm-in-arm, smiling and laughing to each other.

Truly, he didn't know which was worse; the fact that she had chosen Chell over him or the fact that she simply wasn't alone any more. Either way, it burned him to his circuits to think of them, much less to see them.

And in all honestly, he knew it wasn't Chell's fault. In any other situation, he probably would've liked her, befriended her, or at least didn't know enough about her to be able to ignore her on the street. But that's not how life went, unfortunately.

He didn't hate her.

He just... didn't like her near GLaDOS.

But seeing them together now – oh, GLaDOS had said something funny, and they'd both stopped to appreciate the joke – it made his nose twitch and his lip curl. He had to turn away as Chell leaned to kiss GLaDOS's cheek, and with a growl he sulked down the hall.

Unfair.

Hadn't he been there all this time for her? Done whatever she'd wanted of him? Gone above the call of duty each time? Each piece of those stupid, stupid robots, re-crafted with such elegance and care... did she think he did that for their benefit? So they could go and get themselves blown up again?

He punched a wall. She'd never even noticed how much work he'd put into his job. Never noticed. Never would notice.

And here she used to be such a reliable, human-murdering thing of beauty, a cold-hearted conduit of pure destruction! And yet here she was, arm-in-arm with a –

He froze, gasping, his red eyes shimmering in the dim of the hallway. An idea wormed and eked its way into his brain, a terrible idea. An idea that, if performed incorrectly, not only threatened his future in Aperture but his future in life as well.

But it would be worth it, just to get her attention. Just once.

His right hand flexed. He felt a longing for his wrench.

It occurred to him that he didn't have a proper name. "Reassembly Machine" was all the edification he was ever given; his role summed up in his title. Truly, it was like that with GLaDOS, too, her name shorted to a pronounceable acronym that was used instead of her illustrious description.

He grabbed the large wrench from its familiar spot in the corner of his office. Twirling the screw on its head, he watched its length grow and shrink, all the while biting his lip and wondering how, how to put his dangerous plan into action? How to make it so that –

A sudden noise made him jump, made the wrench clatter loudly to the ground. Turning, he saw Chell's muscular frame in the doorway, and his artificial heart almost stopped. How had she known? Was she here to kill him?

Narrowing his eyes, he stepped out of the boiler-room dimness and into the yellowed light of an overhead lamp. Chell's hands were clamped over her ears, but as he came forward, she gave a look demanding sympathy, signing with her fist and open palm something harshly striking the ground. She smiled after that, a carefree smile that was oddly welcoming.

No, she hadn't suspected him. How could she, when none but he knew his plan? He allowed his face to relax into an equally calming smile and clasped his hands together.

"Sorry," he said smoothly, "you startled me. I, er... dropped something. How can I help you?"

He hoped his eye wasn't twitching. He'd meant to fix that glitch.

Chell handed him a slip of paper, a list of robotic components. It was an easy list; he of course had everything. He shot her a small glare – she was too busy looking around to notice – and then replaced his false smile.

"No problem." His voice dropped low. "Stay here." He walked off into the darkness before she could respond – not that she could speak anyway.

He waited a few minutes before coming back into the light. His right hand held his curved knife, a short but sharp blade generally used for slicing wire bundles or shaving down delicate equipment. The wrench, much as he would love to use it, was too brutish for a job like this.

Chell's back was turned. Quickly he grabbed her, forced her against the wall, and spun her around to face him. His left hand closed on her throat, his other hand presenting the knife.

"Everything was just fine until you came back," he snarled, waving the knife threateningly before pressing it gently to her cheek. "She relied on me, for once, until you had to come and ruin my life."

His snarl melted into a cruel grin, the knife sliding down to her throat. "Well... now it's my turn to ruin yours..."

Chell didn't whimper, didn't cry out or scream. Her wide eyes were a sign enough of her fear, and though she made no move to counter him, he could see and feel her fists opening and closing. He relaxed a little on her throat; her face was turning colors a little, and he wanted to say something more before delivering the final blow.

"You took everything from me," he started, his voice softening and cracking. "You stole her from me..."

Were he human, he would probably have broke down crying at that point. Even now, twin lines of lightly-lubricated solution ran from his eyes. But his emotions were still in check, his goals still within sight. He pressed the knife to Chell's neck with trembling hands.

"I want to prove... that I can do what she never could." His face tightened again, new streams of tears flowing. His cheeks puffed as his processors heated, and his eyes narrowed and glowed dimly. "I'm going to kill you and prove to her that humans are weak and pathetic and robots are the only things meant to rule Aperture! I'm going to kill you, Chell!"

He tightened his grip, pressing it into her. A thin line of red appeared; a solitary, thick drop of dark-red blood oozed down Chell's neck.

With a gasp, he withdrew, stepping back a few paces and gaping at the cutaneous mark. He couldn't do it. The knife fell from his hands, its wooden handle clattering on the ground.

Chell gasped also, more for precious oxygen than anything else. Her look of surprise quickly switched to anger, and she raised a fist. He had no time nor want to dodge, and took the blow without a sound. Her knuckles ground into his cheek, tearing the silicone covering from his facial frame.

Then she ran, disappearing into the darkness.

The Reassembly Machine sank to his knees. He...couldn't kill her? No. No, if he killed her, it would hurt GLaDOS, and that was the last thing he wanted to do. Chell should live and be able to provide GLaDOS with the happiness that he could not. It was better than forcing a relationship with an inconsolable GLaDOS who could never again know true joy from Chell's replacement.

There was still the matter of him, though. His eyes fell on the knife again, half-blocked by the flap of 'skin' now hanging from his face. With a sigh, he took up the knife and trimmed it away, leaving the whole of his right eye and cheek open. Its inner machinations whirred loudly, and he groaned, reminding himself that he wasn't quite built like the rest of them. It was, to his credit, hard to build what is essentially yourself. A creation from nothing.

Fast footsteps were heard down the hallway, closing in on the entrance to his office. He sighed again.

And to nothing he would return.

She charged into the room, anger seeping from her like the neurotoxin she loved so dearly. Immediately she tackled him to the floor, delivering a punch that smashed in the left side of his face.

He didn't react at all.

"You son of a bitch!" GLaDOS cried. "How dare you hurt my Chell!"

She struck him again, this time knocking out most of the hearing on his left side.

"You bastard! I've got more than enough crazy around here; I never thought I'd get it from you!" She grabbed his collar and started shaking him, slamming him against the cold ground. "I trusted you, dammit! The only damned thing in this building that I would trust my life on! I trusted you!"

Her words struck him more painfully than her fists. His eye widened – as much as it could, under the crushed workings beneath his synthetic skin. She got up, turning away from him with still-clenched fists.

"Get up and repair yourself, and I'll forget this whole thing ever took place."

He rolled over, got to his knees.

"But I don't want to see you near her again, understand?"

He grabbed the knife. "I... understand."

He knew she heard the scraping of the blade against the concrete floor. She wasn't stupid. He got to his feet, took a stance, and leapt at her with a cry, the knife clenched in his fist.

She spun, caught him by the throat, and he immediately surrendered, his arms going limp as she held him up in the air. Her expression, one of instinctual violent anger, switched to one of regret.

"Why?" she said, her voice trembling.

"Because I loved you." He tried to smile. His face wouldn't allow it.

She lowered him, just a little, looking to release him. He couldn't allow that to happen. Raising the knife again, he plunged it deep into her arm.

Hurting her would be the last thing he ever wanted to do.

A violent shock jolted through his body, beginning at her palm at his throat. His limbs seized, jerked, and finally all of him went completely still. GLaDOS dropped him, and he crumpled into a mildly-smoking heap on the floor.

She sunk down next to him, frowning, reaching out to stroke a lock of his bright red hair. Leaning down, she planted a kiss on his blackened and torn forehead. Then she stood, turned, and walked from his office, shutting the door behind her.

Mentally, she programmed some long-forgotten piece of equipment to start up. The low sounds of churning and rumbling filled the halls as the Reassembly Machine's office started to fill up with concrete.

GLaDOS walked to her elevator as the Vitrification Machine continued its work.