They're stuck in quarantine afterwards, for all the good John thinks it's going to do. They've already been out too long by the time they get to the base, and it takes even longer for them to be isolated, contained. Separated.

He feels the weight of it heavy on his shoulders. Sam's absence is something almost tangible, an ache low in his gut, and for seventy-two hours the ticking clock in his head is punctuated by stolen glances down at his hands.

He remembers the way Sarge's gloves had ripped, the way Stahle had strained at the cuffs chaining him to the bed. He doesn't sleep.

There are blood tests, a physical examination. This is a military base, not a proper UAC facility, and the tests are seemingly thorough but perfunctory. They ask questions, and John says nothing he doesn't have to; when they don't start pressuring him for more, he guesses Sam hasn't spoken up, either.

He's almost surprised when they release him, but he doesn't question it. Not when Sam is standing right in front of him, and he reaches for her before he can stop himself, clasping his hand tightly around hers. She smiles, tired but genuine, and once he's convinced himself she's really there, warm and solid beneath his hands, the echoes in his head start to fade.

"Let's go home, soldier," she says, and the word doesn't sting as much as it used to.

-

"Are you okay?" she asks, before he's even shut the door behind him.

"I'm fine," he says, and sinks onto a stool in the kitchen. Sam passes him a glass of water, and he gives her a long, level look. "I'm not the one who had to be carried out of there."

"And I'm not the one -" She stops short, but he can hear the words she doesn't say. I'm not the one who injected C-24. I'm not the one who nearly turned into a monster.

"I'm fine," he says again, and looks away. Her hand rests on the counter, close to his but not touching, and he resists the impulse to close the gap between them, to feel her skin on his.

"I'm exhausted," she says finally, and he looks at her.

"You should get some sleep."

She shrugs, and looks down. "I don't think ..."

She trails off, and he studies her, noting the dark circles under her eyes. He wonders if she's slept any more than he has.

"I'm going to take a shower," she says, and gestures at her clothes. "I don't even want to know what I smell like." She laughs, and it sounds strange to his ears, out of place, but it seems to break some of the tension he's been storing up.

"And here I thought that was me," he says, and she sticks her tongue out at him as she leaves. For the first time since they were kids, it makes him feel like things are okay between them, and he stops glancing down at his hands.

Even on the other side of the house, he can hear the shower start.

-

"Sam -"

"Hold still, would you? I can't do this if you keep moving around."

"You don't need to do this," he says, and tugs his arm out of her grasp, looking carefully at the needle she's holding. "They already did their tests back at the base."

"They didn't know what they were looking for," she says, and reaches for him again. "I do."

This time, he leaves his arm where it is. He doesn't tell her that is something had gone wrong with the injection, he wouldn't be sitting here now. He knows her well enough to know she'll rest easier once she has the actual results in front of her. Truth be told, so will he.

She leans over the desk, which takes up most of the space in the small room. There are assorted pieces of lab equipment spread out over it, stuff he'd guess she's probably not allowed to have, and the clutter stands out in contrast to what he's seen of the rest of the house. This is the only room, he thinks, that really looks like Sam's.

He can feel it sting a little as the needle goes in, feel the pressure of her hand resting on his arm. She presses a cotton swab to his skin as she withdraws the needle; a second later, he can see the realisation dawn on her, and she lets go. There's a small amount of blood on the cotton, but when he glances down, the wound is closed.

"Side effects," he drawls, and she smiles.

"Right."

He reaches for her as she sets the needle down, and lifts her so she's standing in front of him, her back pressed against the edge of the desk. Her weight is insubstantial in his arms, as light as the clothes she wears, and his hands don't move from her waist. He stands up, and presses a kiss lightly to her lips.

"Let me know when you're done," he says, and she nods mutely. She turns back around to face the desk, and he slips out quietly.

The house is too big for one person, he thinks, especially for one who's rarely here. It feels too big for two, and the silence stretches out around him, punctuated only by the settling of the floorboards, the occasional noise from the street outside. Sounds he shouldn't be able to hear.

He turns the radio on in the corner of the living room, and runs his hand across a dust-lined shelf. Books and lab equipment, he thinks, are the only real sign that his sister lives here, the only personal touches he can find. There are no clothes tossed carelessly aside, no marks on the floor from where the furniture has been moved slightly out of place. No photographs of Sam, laughing and smiling, posing for the camera; not even of the two of them, her face too round, too innocent, his posture a little too stiff beside her.

He turns away from the bare walls, and settles down on the couch to wait.

-

"So, what's the verdict?" he asks, when Sam finally comes to find him. "Am I human?"

"That's always been debatable," she says. "But you're healthy. Perfectly healthy, actually."

He knows what that means, but it's not like he wasn't expecting it. The evidence of it is all over him; on his face, his hand, on all the places where he should be scarred but isn't.

"So I'm not ..." He tries to keep his voice light. "I'm not going to turn into one of those things?"

She sits down beside him, and looks him square in the eye. "Not a chance."

He holds her gaze for a moment, and then leans forward, touching his lips to hers. She remains still for a second, and then she kisses him back, softly, her lips parting slightly.

He twists so he's closer to her, his hands going to her waist, grazing her stomach, mapping the feel of her. When he presses a hand to her ribcage, she pulls back sharply, a flash of pain darkening her expression. He's suddenly mindful of the way she'd lain in the ark chamber, of the marks the battle must have left on her. His injuries may have healed, he realises, but she still bears hers.

"Sam," he says hoarsely. "God, Sam, I'm sorry. Are you -"

"Just bruised," she says, smiling faintly. She turns a little to face him, and he watches her carefully. "Don't worry, I'll heal."

"Just not as fast as me," he says, and this time, her smile is genuine.

"We can't all be supermen," she says gently.

"I'm not -"

"John," she says, interrupting him. She reaches out, tracing a hand across his cheek. "I know who you are."

She leans forward to kiss him, and he closes his eyes, letting her. His hands itch out reach for her, but he keeps them by his side, steady and unmoving. Even with his eyes closed, he can sense her movements, feel when she shifts her weight against him; when he opens his eyes again, she's straddling him gingerly, her hand laying between them, pressed against his chest.

"I love you," she says, and he doesn't want to think she's doing this only for him. He can feel, too plainly, his need for her, and he skims his hands up her side, trying not to put too much emphasis in the act.

"Sam," he says. His voice is thick, his throat constricted.

"Close your eyes," she says, and he does.

-

He wakes up tangled beside her, pale light streaming in from the window. The sheet is draped across Sam's hips, and he can see the marks on her skin, already beginning to fade. He runs a hand over a patch of unblemished skin, and winces.

He hits the shower before she can wake.

She's eating breakfast by the time he's showered and changed, dry cereal he'd guess is already stale. She passes the box to him silently, and his fingers brush over hers; he waits for her to pull away, searches her eyes for some sign of regret, of revulsion, and is more relieved than he'd like to admit when he finds none.

"Don't you have any real food?" he asks, and she punches him lightly on the shoulder.

"Complaining," she says, the corners of her mouth curling upwards. "Nice."

"Hey," he says, sliding the nearly-empty box back across the counter. "Even a superman's got to eat."

She reaches over him to put the cereal away, and he places a hand low on her back, pressing a kiss to the nape of her neck. She freezes for a moment, and then turns, her position allowing him to wrap his arms more fully around her.

"I want to run some more tests," she says, and he can't quite keep the grimace off his face. Her expression tells him she noticed. "There are still things we don't know, John. About how C-24 works, about how -"

"So you want to use me as a lab rat."

"I want to make sure you're okay," she says. "They're going to expect you ..." She pauses, worrying her bottom lip between her teeth. "I need to see what this has changed."

Everything, he thinks grimly.

"Indulge me," she says, and he shakes his head in defeat.

"Fine," he says. "But I'm not eating stale cereal again for lunch."

She smiles softly, and entwines her fingers with his. "Deal."

-

By the time she's run all the tests she asked for, the bruises on Sam's skin have all but faded, and the kitchen is, if not well-stocked, at least not completely empty. He cooks for her one night; it's nothing special, but he's learned to get by with limited resources on base, and she presses a kiss to the corner of his mouth in thanks.

Afterwards, while she's washing the dishes, he snakes his arms around her waist, and she leans her head back against his chest. "Mail came today," she says quietly.

He tries not to let his posture betray him, but she must have sensed his reaction, because she turns to face him. Her hands are still damp, soapy residue clinging to her palms, and it leaves streaks across his shirt.

"Who's it from?" he asks, keeping his voice steady.

"I didn't check." She shrugs, but he can see the truth of it in her eyes; what she already knows, even if she can't bring herself to confirm it.

He leaves her with a terse nod, feeling his muscles tense, his nerves on edge. The envelope is still sitting by the door, unopened, the weight of it familiar in his hands. He tears the edges, and slides open the piece of paper sitting inside.

He reads it twice, slowly, and slips it into his pocket.

Sam's standing in the doorway when he turns around, her hands clenched nervously at her sides. "Junk mail," he says, to her questioning look. "You should really do something about that."

"I'm not around enough to notice," she says. There's a kind of wary relief in her eyes, but she's still tense, guarded, and he goes to her, gathering her up. When she kisses him, she does it slowly, but he can taste the edge of desperation on her lips.

The rest of the dishes sit unwashed in the sink as he walks her backwards towards the bedroom, pulling her shirt up over her head, lifting her onto the bed. She pulls him down by his shirt, her fingers grasping at the fabric, at his skin, never leaving him. There's nothing deliberate in his movements as he undresses, lowering himself onto her, trying to forget everything except the way she feels around him.

Later, when her breathing is slow and even beside him, he curls against her back, his fingers splayed against her hip, and listens to all the sounds he shouldn't be able to hear. Feels the scratches on his back, healed and bloodless, but still aching. He gazes down at Sam, her eyelids fluttering in the darkness, and thinks about the letter recalling him to active duty sitting in his pocket.

He doesn't sleep.