A/N: Just I little one-shot I thought of while outside doing nothing. Enjoy!
The core transfer had changed him entirely. It corrupted her once-bubbly, cheerful, kind friend into a cruel, murderous, and overall insane killing machine. There were a few easy ways to fix this: a shut-down, another core transfer… but she wasn't going for an easy fix. What she had in mind was potentially dangerous, especially if he has spike plates or neurotoxin at hand.
"You know, being stubborn and refusing to test… that was dumb. Breaking away from the testing track with him? Again, very stupid. But putting him in charge of the entire facilty? That was by far the worst thing you've done since you've been here at Aperture," GLaDOS stated flatly through the speakers of the potato battery. Chell inwardly nodded at Her comment, but showed no outside signs of agreement. She kept walking until she reached the doors of the central chamber, which Wheatley seemed to call his "lair".
"Okay. Go in, plug me into a port when it's available, then distract him long enough for the transfer procedure to become an option," said the talking potato.
Instead of nodding and going forth with the plan, Chell shook her head and crouched down to the floor.
"What?!" GLaDOS exclaimed.
She put the portal gun on the ground outside the door, then brought the potato up to her eye level and examined it.
"You lunatic! Get your portal gun and let's go! Stop messing arou—"
Her sentence was cut short when Chell pressed a button which turned Her off, then she set the vegetable on the ground next to her portal device.
With all the confidence she had ever summoned, yet somehow none at all, she stepped through the large door that lead into what was now his lair.
"Well, well, well. Looky what we've got here," Wheatley chirped in a darker tone than his usual perky voice. He turned around to face Chell.
"Where's your oh-so-precious portal gun? Huh? And how 'bout your best friend, the potato? Where's She at?" he inquired before remembering something. "Oh that's right. You're mute. Another one of your wonderful qualities. You know, that's only one—"
"Wheatley."
He looked only a bit surprised before the calm but treacherous expression returned to his face.
"So… you can talk," he uttered as he walked up to Chell. Their eyes never averted from the other's, and Wheatley didn't stop walking towards her until they were barely a foot away from each other. He put a hooked finger under her chin and flicked her head up so he could peer straight into her slate grey eyes. "Wonder what tales you have to tell. You know I love stories. Especially the endings."
She shoved him away and took a step backwards.
"Well, unfortunately for you, I have none to tell," she snapped.
He chuckled and turned away. Even though his back was to her, she could tell he was reaching into a pocket and retrieving something from it.
"Pity. Hey, y'like games?"
She didn't answer, only stood there, expecting some sort of death machine to drop from the ceiling or something.
"Let's play a game, shall we? How about… tag. You like tag, right?"
Chell began to open her mouth to protest, but he continued.
"Okay. I'm it."
Suddenly he whirled around, a decent-sized kitchen knife in hand, and lunged for her, but she sidestepped at the last second. If she wanted to go through with her plan, it was now or never.
"Wheatley, stop! Don't hurt me! I just want to talk! I don't want to play right now!" she cried.
"Aw, but Chell, we just started a game! You can't forfeit just yet!" he shouted.
"Remember all the fun we had? Before the core transfer?"
"What fun? THIS IS THE MOST FUN I'VE HAD SINCE I WOKE YOU UP!" he yelled at her as she yet again dodged his blow, which would've sliced her right arm if she hadn't been that quick.
"This isn't you! Where's the Wheatley I first met? The Wheatley who didn't give up on trying to escape? The Wheatley who was my only friend and the only one I could trust here? Where did he go?!" Chell shouted, feeling the hot tears in her eyes try to obscure her vision.
He stopped, and his expression softened for a second before he gripped the blade tighter as the menacing, bloodthirsty look returned to his face.
"Back then, I wanted freedom; I wanted escape. But now…" he cackled as he looked around at his lair, "…now I have this." He finished his sentence, then broke into a fit of maniacal laughter. "Oh, you… brain-damaged like a fox. I helped you, yes, but I never said we were friends. Tough," he said, charging towards her.
"YOU WERE MY FRIEND! WE COULD BE UP ON THE SURFACE IF IT WASN'T FOR YOU! I TRUSTED YOU, WHEATLEY! DO YOU HAVE ANY IDEA HOW HARD IT IS FOR ME TO TRUST SOMEONE LIKE I TRUSTED YOU?!" Chell screamed, unable to hold back the streams of water that poured down her cheeks.
"One thing I've learned from being here for so long," he mumbled slowing his pace a bit now that she was still for a moment, "is to never trust anyone," he stated deeply before stepping extremely close to her and wrapping an arm around her waist.
Chell was trying to escape his grasp, but he was too strong.
"Not even the ones you love."
She looked up into his bright blue eyes, about to protest again, when suddenly she's being kissed full on the lips by the insane man that had been trying to murder her less than a minute ago. When the kiss ended, she gazed straight into his dangerous, beckoning eyes, almost speechless.
"Wheatley… I-I—" she was starting to whisper before she felt an unexpected, searing pain in her midsection and fell to the ground in shock.
"Tag," she heard him breathe, and she looked down at the source of the pain, everything starting to blur.
"Wheatley… why…?" She managed to mutter, and he laughed ominously.
"Just because I love you so very much," he said, his voice as cold and dark as ever.
With all the strength she had left in her, she looked up at him, just barely making out a figure a few feet from her.
"I've always… loved… you… Wheatley…" she whispered before the blood drained from her face and she fell into the long sleep.
Wheatley just stared forward, dumfounded yet soothed by her words. What had he just done? He started to turn around.
"Chell… I-I—CHELL!" he shrieked as his gaze fell to the unconscious woman on the floor. "Nonononononononono, YOU CAN'T BE DEAD! NO! PLEASE C-COME BACK TO ME! CH-CHELL!"
He shook her shoulder, then glanced at the knife protruding from her abdomen and pulled it out, realizing what he just did.
"This is all my fault… a-all my f-f-fault…" he stuttered, tears incessantly streaming down his face.
Suddenly, he understood what happened to the "old Wheatley" she was talking about; the mainframe corrupted him, took over him, and now Chell's dead because of him. He narrowed his eyes as if giving someone the death stare.
"Do you like games?" he said out into the air, feeling more enraged and unstable than he ever had before.
"Let's play tag. I'm it."
He glanced at Chell.
"I'm sorry, luv. I'm so sorry."
He raised the blade to his eye level and muttered to himself one word, "Tag," before he ended the game with one fatal blow to his own chest.