For mik100's birthday, who wanted a scenario where John has absolutely no control. The character who dies is actually my favourite, so I assure you, this hurt me more than anyone. Beta-ed by Chandri.
Spoilers for Outcast and Critical Mass.
A heavy body is holding him down. He tenses his muscles to fight against it when his muscles begin to relax against his will. He panics, but his breathing doesn't change. His heart rate is actually going down.
He watches his field of vision turn to left, sees at an oblique angle a dumpster blanketed in dim orange light. What's happening?
John can feel the body on top of his - it's limp now, dead weight. He feels muscles coordinate, push himself up, and then the other body drops to the pavement with a dull thud.
He's confused. His body isn't reacting to his thoughts. It's got a life of its own. Oh no no no no-
I command the body called John Sheppard now. He hears in his mind, a deep voice.
He wants to yell, scream for help, or as a warning, but he can hardly form a mental sentence. His lips don't even twitch. This is my body, he thinks, and get the fuck out.
He sees his eyes look down. The man who attacked him lays awkwardly, his dark eyes half open, staring at nothing. His mouth is lax and left open, blood pooling out of it. He's expressionless.
John sees his hand reach down and peel off a golden metal device of some sort from around the other man's wrist.
I am your master, the voice tells him.
The voice is the one telling his body what to do. It's disorienting, not knowing when he will inhale and exhale, what will fall into his line of vision.
It's a goa'uld in his head. But John's still here too. Surely he can fight.
He tries to seize back control of his muscles. He tries to tell his legs to take him a different direction. All of his will concentrated to a single action. The legs - his legs - don't even stumble. Not even for a second.
He tries something different, tries to start smaller. He tries to blink. It doesn't work. His eyelids may as well be a two ton weight for all the movement he can initiate. He gives up on them.
Then he blinks. Was that him?
The voice laughs.
By the time he reaches the SGC, John's decided active action might not be feasible. The goa'uld has tight control of his motor functions. But all he has to do is act out of character. What do reptiles know about social interaction?
At the security entrance, the voice in his mind signs his name exactly like his does. He feels the learned motion stolen out of his brain. The action feels identical, as though it was his own hand. The voice smiles with John's face, and John sees the airman smile back.
Stepping out of the elevator, John sees dozens of SGC personnel in the corner of his eye. He tries to make a noise, or trip. They all ignore him.
The voice greets General Landry outside of the gate room. It's his voice, it even sounds like his words. Isn't it standard procedure to have MRIs to check for snakes? They don't seem to be doing that right now. They must only check when one was arriving on earth.
He wishes he could feel the sinking feeling in his stomach that should accompany that line of thought. But he feels fine, though perhaps a little bored.
He meets Ronon outside of the gate room. Ronon will notice something. He'll look into John's eyes and just know.
"Hey Sheppard," Ronon says.
The voice replies with John's face and larynx. It doesn't sound too different, but it most certainly doesn't sound like typical John.
And then there's silence. This isn't really weird of behaviour for him, he realises. Especially since his father just died. Oh god - is everyone going to assume that's the reason for his strange behaviour?
Inside of his mind, the voice seems pleased. His body feels relaxed and content. John wishes he could physically feel his dread.
Sheppard can hardly follow events as they step out of the wormhole. The voice moves his eyes around unpredictably, and chooses what images get to be in focus, chooses the orientation of his head, as well.
Colonel Carter isn't in the Gate room to greet their return. It must be night time on Atlantis.
He remembers something he read in a mission report, that Colonel Carter had once been possessed by a goa'uld. It left her with the ability to sense the presence of other symbiotes.
Perfect. She would discover the presence of his hijacker. So maybe he isn't able to alert Atlantis to this intruder - he doesn't have to.
He feels his body tense slightly. His heart rate increases, he feels some anxiety. Take that you bastard, he taunts at the voice.
It's a good thing you warned me, the voice tells him. His body calms down, his breathing evens out, and John gets worried. I'll resolve this threat promptly.
He can feel the voice flipping through his brain like it's some kind of encyclopaedia. It's looking for information.
No way, he tells the voice. His legs are taking him to Colonel Carter's quarters, and he can't turn away.
He rings the bell outside her door. There's nearly a minute's wait before the door opens and John feels anticipation.
You son of a bitch, he yells at the voice. What the hell do you want? Don't do this!
He can't stop his body from slamming Sam back into her quarters, against a wall; his hands push over her mouth and her nose, catching strand of blond hair caught between his fingers, all before she can even scream. John tries to close his eyes, to not watch, but all he can do is feel the voice's pleasure as he sees Colonel Carter's eyes, giant and grey and terrified.
With very little effort, he snaps her neck. The voice is delighted - his body feels giddy, and John wishes he could feel nauseous instead. She collapses to the ground with a deep thud just like the sound of the previous host's fall.
John can't stop himself from realising that his DNA is all over Samantha Carter's body. Before he even has a chance to build some hope about being discovered, the voice has absorbed all of his knowledge about crime scene investigations and is preparing to dispose of the body.
She has a balcony in her quarters. John watches himself throw her over the edge, not entirely understanding what the voice was trying to do. It would know as well as he did that she would be found soon.
Hear hears a faint splash, smells the fresh wind and ocean, and feels his lips smile.
He knows he should be upset but his body feels energized and aroused. John himself has no influence, just a corner of thoughts.
The next week is passed as a disconnected observer.
John is mute and paralysed. He's incapable of having his own visceral emotions. All of Atlantis is concentrating on their missing leader and no one even notices that John is not in control of his body.
After he murdered Sam, John quickly found that he couldn't bear to fight anymore. He's exhausted from working so hard and achieving nothing. When he does mentally involve himself in a situation, John discovers, the voice just gets more ammunition.
Every thought John has the voice violates. It knows exactly what he cares about most.
The voice notices right away that when it goes close to Rodney, John immediately renews his efforts in fighting back. Every time.
The voice takes malicious delight in teasing John. When it's bored, it will tell John it has a wonderful plan which usually involves Rodney's torture and murder. John has already received an explicit demonstration of his own hands killing a friend, he dreads an encore.
His mind is filled with blood and terror. Each scenario is more gruesome than the last, and John must not only see the imagined result, but feel the voices pleasure of it as well. And every time the voice makes him approach Rodney, even though he knows he has no chance of beating the voice, John wearily begins to fight again.
John watches as Rodney looks confused by John's distant behaviour. Notice, he urges Rodney. Please god, notice something's wrong.
"You okay?" Rodney says one day, maybe three days or four, after he's murdered Sam. "I mean, you've been acting a little weird."
Yes. John wants to Rodney to say more, speaker louder. But he can feel the voice paying attention. It's the voice which chooses to look up from his meal and make eye contact with Rodney. Don't say anything else Rodney...
"I get back from my dad's funeral and then Sam goes missing..." The voice makes him say.
Rodney nods and sighs, his face lined with tension, worried about Sam and probably worried about John too.
John thinks that he would cry if he could. Instead he takes a bite of some macaroni and cheese.
John is looking at his hand, adorned with the golden device the voice had stolen from the previous host. He tries to loose himself in the rhythmic glinting from light bouncing off of the metal. Instead, he has an epiphany.
He can't move. He can't even feel. All he has, all he is, are his thoughts. And they're irrelevant. He wishes for oblivion.
John receives the incoming radio message: The Daedalus has arrived.
His body immediately fills with excitement and John simply knows. This is what the goa'uld has been waiting for. He can't bring himself to care. Instead, he lets himself get swept up in the goa'uld's anticipation.
There are meetings, discussing the disappearance of Colonel Carter. Flashes of faces – Colonel Caldwell, Major Lorne, McKay; John doesn't pay attention. He's almost able to block out his consciousness entirely, but at some point he does faintly hear a commotion.
They found Carter's body.
Later on, he goes to his quarters and collects the hand device. He radios Colonel Caldwell for a beam up. This is the moment the goa'uld has been waiting for.
He's on the Daedalus, the golden device wrapped around his wrist. He feels bloodlust rushing through his body. His arm stretches out and the bridge crew does flying in every direction. His eyes flash.
He enjoys hearing their cries and shouts and tries not to think about these people as friends and colleagues. Colonel Caldwell isn't on the bridge, but he doesn't take the time to think why that might be.
And then he feels a sharp stab into his thigh. Tranquilizer dart. In quick succession, a second hits his thigh, and a third hits near his collar bone. He feel's the goa'uld's surprise.
John wonders how they figured it out. His field of vision is beginning to blur, but he can see a figure approaching him. It's Caldwell.
Caldwell could also sense the presence of a Goa'uld. John hadn't been paying attention, he hadn't even thought of that.
He stumbles, his legs trembling. John isn't controlling his body, but the voice isn't the one in control either. He can't pull together enough energy to feel triumphant. His knees buckle. As his vision fades out and he hears Caldwell's voice growing less distinct, John only feels the voice's fury.
Three loud knocks on the door jars John into the present. He blinks a few times, reminding himself to pay attention. The sunlight streaming through the window onto his hospital bed is at a much lower angle than the last time he noticed.
He turns his head to the left to see who it is at the door.
For a moment, no one comes in. And then he sees Rodney stride across the room, sitting himself down stiffly on the plastic chair next to John's bed. John stares straight forward at the wall across from him.
From the corner of his eye he sees Rodney look him up and down, appraising his sweatpants and t-shirt. His uncombed hair.
"Ah, hey." Rodney says. He sounds nervous, probably ready to dart back out of the room. Well who can blame him – John has blood on his hands.
John forgets for a moment that he's supposed to participate, to answer back.
"They tell me you've been talking a bit now," Rodney picks up the conversation himself, "that you're recovering really well..."
Rodney sounds terrified; he might even be on the verge of rambling. John finds himself grateful for Rodney's company, even though a part of him is still accustomed to being terrified about being in the same room with him. With the things he has thought, planned, felt...
There's a long silence.
"Rodney," he says. His voice sounds scratchy, he's hardly said more than a dozen words in two weeks.
Rodney waits, uncharacteristically silent.
He closes his eyes and sees dark red blood and hears that awful thud when a body's completely limp. A strangled sob-like spasm surprises him.
"I'm sorry," he whispers.
"It's not – if it's anyone's – look. It's not your fault. None of it."
He looks up and sees Rodney's face earnest, and something else. He doesn't know what.
John shakes his head, "I shouldn't have fought," he confesses. "That's how it knew what to do next. I shouldn't have...if I hadn't thought about Sam..."
Rodney doesn't reply. He probably hates John, and he should. John understands.
"You couldn't have done anything else," Rodney says. John doesn't reply; he doesn't deserve Rodney's absolution.
He hears Rodney exhale sharply and stand up, pushing back the plastic chair.
"Look," Rodney says, "I wouldn't say it if it wasn't true, okay?"
Rodney lets out a tense breath and adds more quietly, "I just want my friend back."
John looks up at Rodney's face, into his eyes. He doesn't understand, but suddenly he does believe what Rodney's telling him.
He struggles for a moment with how to reply.
"Thanks," he says.