Poison.
After everything he'd done to protect her, every time he'd stepped in front of her, every time he'd taken the blow for her, and it was fucking poison that was taking her from him.
It was like some cruel joke of fate, he'd finally repaired the trust he'd so horrendously shattered all those years ago, finally gotten back on good terms, finally gotten his only friend back, and now she was being ripped away from him.
And all he could do was stand by and watch, watch as the one person he'd cared enough to repair his bond with get taken from him, as though everything he'd done to finally get her back didn't matter in the least.
Maybe he deserves it, for destroying her trust in the first place. Maybe he deserves to lose her, maybe he didn't even deserve to ever speak to her again, after everything he did. He should feel lucky he managed to get as far as he did in terms of repairing their friendship, shouldn't he?
He should, but he can't find it within himself to be grateful for anything while his best friend is laying immobile on a bed as the life drains out of her.
The delusions have already started, and she's holding his hand as she's forced to relay the hell they'd managed to escape, the hell they'd manage to leave behind and start anew after. Is this also part of the fate? It wasn't bad enough that she was going to leave him, but she has to relive the worst experience of her life while she does?
No.
He grits his teeth. There's no way he's going to let her die trapped inside the prison her mind has constructed. Just because fate has decided to torture him doesn't mean that it gets to torture her, not while she's taking her last few breaths.
He will not let her her last moments alive be painful ones.
He sits down on the edge of the bed, taking her hand in his. She turns her attention to him, their eyes meet. The blue orbs, usually so full of energy and excitement, appear distracted, as though her conscious is off in some other dimension, she's not really there.
She sees him, she's subconsciously registering his presence, but her mind is primarily occupied.
He bites his lip, takes a deep breath. Plasters on a smile as he tries to stead his voice.
"C-Chell? C-Can you h-hear me?"
Her posture, previously laxed and distracted, seems to straighten itself, and her eyes suddenly seem to fill with life as she registers the words. She slowly brings her hands from her sides to directly in front of her chest, struggling to keep them steady as she signs out a word.
'Wheatley'
He smiles a bit, it's working! She can hear him even through the delusions, there's hope.
"Y-Yes! I-it's me Wheatley! I-I'm here to get you out, w-we're escaping Aperture!"
A ghost of a smile, it's all she can manage, forms on her lips. Wheatley's grin widens, it's actually working! He can talk her out of this!
He takes one of her hands in his, turning his gaze onto her.
"O-Ok we're almost to the main chamber, j-just gotta get past this one room."
A meek nod, the girl's expression is suddenly determined. He recognizes the expression, it's the same expression she carried back in the real Aperture, the expression that was painted on her face as she solved countless tests, narrowly escaped traps, outsmarted both him and GLaDOS. The expression that never ceased to amaze him, and apparently still hasn't.
"O-Ok, t-the turrets s-should be broken, because we destroyed her machine! R-Remember that?"
Another nod. Another relieved sigh from him. From what he can tell, her subconscious is running on her memories from Aperture, but it's also open to input. That's good news for him.
"Yeah, s-so, a-all the turrets are broken, a-and they don't work. S-So we can just w-walk right on through."
A softer nod, significantly weaker. He bites his lip again, she's running out of time.
"A-Alrighty, were in the main chamber now, yeah? Yeah, a-and look! All her defenses are down, just plug me into the mainframe a-and I'll start up the elevator, and we'll be out of here...!"
He's significantly more nervous now, he doesn't know how she'll react. This is the part where he destroyed their relationship all those years ago, the part where he did the one thing he regrets more than anything else, where he betrayed her. He keeps his gaze fixated on her expression, artificial heart pounding inside his chest in a way that was so real he might've exploded from anxiety. She nods again, and he keeps her hand grasped tightly in his, as though breaking contact will kill her in that very instant.
"O-Ok, what are you seeing right now?"
As much as he hates it, she pulls her hand away to weakly sign him a reply, and he mentally curses Aperture for removing her ability to talk, for making her last living moments all the more painful.
'GLaDOS'
It's only one word, one name, but it holds so much weight. He too remembers what she's reliving, seeing her in the chassis, right before they removed her, removed her immense control and granted it to him, right before he betrayed his only friend. Another deep breath, and he can only pray that he's able to change that part, that he's able to give her a better image to go out on.
"Yes, ok, there should be a button at the far side of the room, r-right?"
Nod.
"P-press it, a-and it'll take away her control."
Nod, and her body gently shifting, barely moving, but he assumes she probably thinks she's running, following his instructions. He's taken ahold of her hand again, and she squeezes it gently, as though he's the one dying and he's the one requiring care and reassurance.
Maybe he is.
"You pressed the button?"
A gentle nod, and the faintest of smiles. She's probably seeing her lose control, she might be hearing it too for all he knows. She's gazing at him expectantly now, he must've gained control.
"O-Ok, I'm starting up the elevator, y-you're in it, right?"
Another nod, the ghost of a smile widens a bit. His smile widens with it, it's actually working! She's going to get out, she's not going to remember—
The contact is rapidly and unexpectedly broken, so suddenly that it takes him a full second to register it. She's signing furiously now, and as he reads the words he can feel himself going pale.
'Why is the elevator going down?!'
He's frozen. No. No no no no no this wasn't supposed to happen! Not again, not now, she's not supposed to have to relive that part this wasn't supposed to happen! She's staring at him, eyes wide in confusion that verges on fear, and he scours his mind for something, anything to change this. Suddenly, he's hit with a feeling, a realization, a memory.
He's not going to let her go out on this image.
Another deep breath, followed by a sudden smile and a grab for her hand, which he gently caresses the back of while holding it.
"S-So that I can get in! Y-Yeah, we're getting out together, remember?"
And just like that, the confusion and fear she'd previously been consumed with had vanished, her conscious completely accepting the words. An audible sigh of relief from him, and his smile, now slightly more confident, is met with a relived grin, albeit a tired-looking one, that so clearly says 'you had me worried there'. He continues to hold her hand, keeping it in a gentle yet firm grip, making himself a mental promise to not let it go again.
"The elevator's going up again, you feel it?"
She nods as enthusiastically as she can, which isn't much, but the grin tells him just how truly happy she is, even if she's not able to express it as much as she wants to. The grin on her face makes him swell up with a mix of relief and happiness, he's done it! He actually managed to do something right for her!
Her gaze drifts up to the ceiling, and his eyes follow. Even though he can't see what she's experiencing, he's sure that he can feel it, feel her excitement and gratitude, and despite the fact that he's losing her, he feels like he's finally gained her back at the same time. He closes his eyes briefly, and he can practically see the ceiling opening up, the elevator lifting them above and beyond the numerous levels of Aperture Science, until finally stopping them with the walls of the exit way, metal door swinging open and greeting them with an endless field of wheat. He smiles, genuinely smiles, at the thought, the image of how it should've been.
His eyelids flutter open, and he opens his lips one last time, words barely above a whisper.
"And we're out."
His eyes fall from the ceiling, coming to rest on her face, and suddenly his calm expression is gone, replaced with eyes that are now wide with shock edging on horror, and lips that are slightly agape, threatening to contort into a frown at any moment.
Her eyelids have fallen closed, and there's a gentle smile on her face, but no longer is her chest rising and falling. She's completely still, and it's in this moment that he realizes her hand has fallen limp in his, it's dead weight in his grip. Her expression is so tranquil, so at peace, she looks like she could be asleep. And technically, she is.
The only catch is that she's never going to wake up.
Those eyelids will never flutter open again, he's never going to see her brown eyes, sparkling and full of joy, again. He's never going to be able to speak with her again, never going to be able to do anything with her again.
Their time together has ended, permanently.
He wraps his arms gently around her still frame, carefully pulling her close to him in a hug, and the longer he holds her the tighter his grip gets, until he thinks he might be holding onto her for dear life, as though his grief alone is enough to bring her back.
And that's when the tears start.