Disclaimer: Mutant Enemy owns them, not I…

Author's Note: Minor Spoilers for the Big Damned Movie. I just thought we missed out on a scene somewhere towards the beginning…

Simon's seemingly impetuous decision to leave Serenity sent ripples of confusion, disappointment, and grim satisfaction through the ship's crew. They'd all known the Tams were outsiders, unaccustomed to the harsh life of the rim, each member of the crew unsure that the siblings would ever really fit into their nomad life

But, their numbers having dwindled down to seven – including Simon's sister, who couldn't be counted as a member of the working crew, not really – the simple prospect of losing two more bodies already made the ship seem lonelier. Serenity's crew had originally been five, but had swelled to nine with their Ambassador renting her shuttle and the arrival of three strange passengers (well, technically two passengers as one had been stashed in a crate - but now wasn't a time to get all nitpicky).

At nine, the firefly had seemed more like a home, filled with extended family. But then Inara left. And Shepherd. And they were seven.

Kaylee missed her real, blood family sometimes, when the ship was quiet and her only company was the humming of her Good Girl's engine – her heart. As she swung in her hammock, though, listening to the steady whirring and thumping that was taking them closer and closer to further and further away, she was thinking on how much she'd miss the newest members of her family.

River had come to be like a little sister to Kaylee – difficult to understand sometimes, pretty troublesome, worrisome, a bit scary, and who got into all manner of mischief without realizing it. But, Kaylee thought that's what younger sisters were like, mostly.

Not knowing River before the Alliance took her and messed with her helped. It meant that Kaylee could accept River as she was. Always having been pretty intuitive herself, she suspected that's why River took to her so much, more than the other crew (except her brother, 'course). It was okay that the girl was strange. Kaylee'd still be her friend. Maybe River wasn't always so much trouble, so strange, so out of synch, having once been a talented genius. Simon said she hadn't been. Kaylee thought that maybe she had, though. Just in a different way. And that's what Simon was trying to get back. What his sister had been.

What she'd lost. What he'd lost.

When she stopped to really ponder on it, Kaylee wondered whether Simon wasn't trying to get back some of himself, too. River'd been having more good days than bad, of late. Many more. But, Simon, well.

Simon, he'd gone and –

"It ain't right." Kaylee told Serenity.

Simon was in his infirmary, tidying up. It mightn't have been His Infirmary anymore, in actual fact, but he wasn't about to leave it in disarray for the others, for the next ones who needed it. If someone was hurt before they could pick up another medic – and someone was bound to get hurt before they could pick up another medic, probably before they even left dock after dropping him off with River – they'd at least be able to find whatever they needed to patch up whomever, afflicted with whatever. Except a doctor. They wouldn't be able to find a competent doctor. Damn.

"There ain't no need to tidy up none, you know. You always keep this place plenty neat." Kaylee had appeared in his doorway, her hand on the doorjamb, steadying her as she leaned her head in to talk with him. Almost like she was holding herself back from coming inside.

"I just want anyone who needs something to be able to easily find what they're looking for." He returned his gaze to the drawer of tapes and weaves as he sorted them by size. Maybe he should also label what kind of wound each would be best for? No. Jayne would still figure out how to mess it up. Maybe if he made the labels with pictures of the wounds on them? Or pictures of the guns that could cause the wounds?

"Yeah, well. Don't put yourself out or nothin'. You know Jayne's just gonna mess it all up after you've left us." Her last words were spoken with a little more force than she'd probably intended, making Simon inwardly wince.

Kaylee was never good at hiding her feelings. It was one of the reasons he'd been drawn to her when he first came on board, even if he'd found the trait slightly confusing and pretty intimidating, to be perfectly honest. But it was one of the reasons she was his best friend on the ship, best friend anywhere; he knew she liked him for him, for Simon. Propriety or not (often in spite of it), crazy sister and all. It was freeing being around her, letting her easy smile and laughter and gentle, caring way coax him out of his shell. He loved telling her stories of his days in the Core, in Medacad, shocking her with schoolboy exploits that seemed so unlike him, stories about another life. He loved to listen to her tell him about her home, her family. He loved to hear the excitement in her voice when she talked about Serenity, her girl.

But, he couldn't afford to let that happen anymore. Not after Mal put River in danger the way he had. That job. The Reavers. God. If something had happened -

And if he stayed, he'd keep getting softer, more comfortable, more open. No, his shell had to be hard enough for both himself and for River. His sister had no shell, no protection from the outside world that had hurt her so badly for so long, maybe beyond repair. Hell, she barely even remembered to wear shoes to protect her feet from the metal decking. He had to take care of her. She was all he had.

"It ain't true." Kaylee said softly, but purposefully. Her voice hinted of anger and bitterness and betrayal.

"What isn't?" He'd forgotten his labeling system, but kept his eyes pointed down at the open drawer, not wanting to see that look she could give, the one where the light in her eyes dimmed and her mouth set into a straight line. The look she gave him when he'd done something or said something particularly idiotic. He had a feeling that she was giving him that look, now. That she knew what he was thinking, what he was feeling, and was disappointed in him.

"It ain't true you and River ain't got nobody but each other. It ain't true that River can't take care of herself none. It ain't true that Cap'n don't care about you. Or River. He does. He cares about you just the same as he cares about the rest of us. You're crew, you're family. I bet he cares about'cha more'n he cares 'bout Jayne, even. Seeing as Jayne can hold his own and can be real stupid sometimes. But you're bein' more dumb than Jayne, right now. Leavin'. It ain't true you can't rely on us. On Serenity. You can. You got Cap'n, you got Wash n' Zoe. You know Zoe'd never let anything happen, even when Cap'n gets all hotheaded. You even got Jayne, though he's got a funny way of showin' it, sometimes – all the time." Her words came faster, though her voice never rose in pitch or volume. It remained steady, quiet, and thoughtful. "You got me, Simon. You know you got me. You n' River both."

She sounded like she was in pain as she told him, in her own way, that he was being a stubborn ass. The fear and hurt in her voice prompted him to pluck up the courage to look at her, wanting to help her understand, to ease her pain as best he could.

"Kaylee, I know that. I know I have you. I know I can count on Serenity. I can't - I can't thank you enough for the way you accepted us. Me. The way you accepted me from the beginning. And River. Even when – even when she scared you." Kaylee dropped her gaze quickly, and he wasn't sure if it was because she was embarrassed at having once been so shaken by River, or whether it was Something Else.

When she looked up, her eyes were brighter than he normally saw them (and he had made a long, careful study of her eyes), their corners glistening. She had let go of the door and had taken a step inside, her arms hanging loosely at her sides, her breath ragged. She sniffled.

Something Else, then.

Damnit. Did she think this was easy for him? Taking his sister away from this place she thought of as home? Taking her away from these people she thought of as family? Did she think it was easy for him to leave this ship, this crew, these people that he cared about without a doctor? Without someone to get them through, as whole and healthy as possible, from one job to the next?

Did she think it was so goddamned easy for him to leave her? The only real friend, besides his sister, he'd ever known? Would probably ever know? He hadn't been able to give her the kind of love that she'd wanted. The kind of love that he'd wanted. Not with River the way she was. He'd been, probably always would be, a Brother first, a doctor second, and Simon Tam third. But that didn't mean this was easy for him. No, it was hard. Really hard. A hard decision from months of hard thinking. It had been a final announcement made in the heat of a moment. But, he'd been thinking about it for longer than he'd wanted to admit. And it had been Really. Damned. Hard.

"Kaylee." He walked toward her until she was just close enough for him to, just this once, take a chance at operating on instinct and grab her hand – their interlaced fingers helping to close the chasm between them. "Kaylee, I have to. I just - I just have to. I wish I didn't. I wish for a lot of things. But, I have to. Please. Understand."

"Oh." Her voice was small, now; her eyes were closed against the tears.

Simon had never been good with people. Not healthy people, anyway. He was bad at sensing moods, at putting his thoughts into appropriate words. He was bad at guessing what people needed to hear, to feel from him. At the hospital, he'd hated talking to patients' families. Even those of the ones he'd saved. And he'd saved most of them. Whatever triumph or joy or sadness or regret or sympathy he felt, it had always somehow translated into clinical speech and halting dialogue. Here, though, now, he sensed that his friend, this bright, beautiful girl he loved, he hadn't had the chance to love, needed to say goodbye. She needed to feel protected, insulated from what was to come. And she needed to feel, at least once, the depth of feeling he had for her, even if he hadn't ever been able to express it.

Their hands still joined, fingers intertwined, he gently tugged her forward and pulled her to him.

And he hugged her. There was no passion, only comfort and not a little longing.

And she broke.

As she cried into his shoulder, he simply held her, his arms crossed so tightly around her back that he held her narrow waist with his hands.

Kaylee felt Simon's lips brush her temple as he kissed her head and laid his cheek on the crown of her hair, as she'd seen him comfort River. She could feel him shaking as he held her, though, clutching tight, not wanting to let go, but forced to by circumstance and choice. He didn't tremble when he held River. She sobbed freely, for the first time in a long while, not caring for the moment if anyone came in and saw her, grasping at some little comfort while her heart broke.

Cap'n and the others had known she'd been taken with Simon – crushed on him pretty bad when he'd first come on board. And she was a tireless flirt. She still joked about it sometimes, complaining to Cap'n 'bout how lonely she was getting' and how Simon'd never play Doctor with her. But they didn't really know. Not really. They didn't know how much she cared for him – thought of him differently than the rest of 'em.

She'd never let on that Simon, when he wasn't too busy stickin' his foot in his mouth, made her feel smart and pretty and funny and interesting, made her feel like she was worth more to somebody she fancied than a roll in the hay, or engine, or wherever. Simon never gave in to her teasing, poking, prodding, suggestions. And he'd still made her feel loved in his own quiet, clumsy way. Maybe more this way. She didn't know. Their friendship was special. Simon was special. Her feelings for him were special. A little confused, maybe, but still special.

When they broke apart, after a lifetime, a moment, of just being together, Simon's eyes were moist with his own, unshed sadness. His shirt was soaked at the shoulder, and Kaylee gave him a tiny, rueful smile.

"Your pretty shirt…"

She knew that when the time came to really say goodbye, she'd probably be strong enough to get through it, to get by. He'd been able to give her that, at least. She'd had her moment and it would be time to move on, soon. But, if she had to lose him, she'd protect what they had together.

She might joke, and she might pout, and she might whine, and she might even shed a few tears. But, she'd never let the others know. It was hers, his, theirs. And she'd never, not ever, tell Mal what he'd truly cost her.