Symptoms

The good days had become fewer, and Xavier had started keeping track of them the way Rachel had once tracked a countdown on a strip of tape — a private tally, unspoken, that told him more than he wanted to know about the shape of what was happening to him.

He'd had three good days out of the last eleven. Good meaning steady hands, meaning a mind that stayed where he put it, meaning he could walk the length of the courtyard without the world tilting sideways in a way that made him grab for a wall he didn't actually need until, suddenly, he did. The other eight days had ranged from merely difficult to the kind of frightening that he'd stopped trying to hide from the others, because hiding it had become, somewhere in the last week, simply beyond his capacity.

"You're doing the thing again," William said, gently, finding him gripping the edge of a doorway with more force than the doorway required. "Talk to me."

"Dizzy. It'll pass." It usually did, eventually, though eventually had started stretching longer each time, minutes becoming something closer to an hour, an hour becoming most of a morning. "I don't want to make a production of it."

"You're allowed to make a production of it, Xavier. That's what we're here for." William's voice had lost, entirely, the dry humor that used to be his default setting around hard things, replaced now by a rawness he didn't bother disguising anymore. "Sit down. Please. Before you fall down and make me feel worse about not catching you."

Xavier sat, and let William's hand rest on his shoulder, steady, grounding, and waited out the tilt of the world with his eyes closed, breathing slow, the way the medical staff had taught him, the way that helped less and less each time he tried it.

The technicians had a name for it now, or something close to a name — not a diagnosis exactly, Ar had been careful to explain, but a working classification built from the sparse historical fragments and the accumulating data of Xavier's own case, the first living example anyone in four million years had actually been able to study. Temporal dissonance syndrome, rendered as close as the translation allowed. The body, and more specifically the deepest structures of the nervous system, apparently experiencing an ongoing, worsening difficulty reconciling itself to a timeline it had not organically lived through.

"It's accelerating," the lead technician told them, three days after the courtyard conversation about the Silex Sxar, in a small consultation room that had started to feel, to Xavier, disturbingly familiar. "I want to be honest with you about that, because I think honesty serves you better than false comfort at this stage. The tremors, the disorientation, the episodes of confusion — six weeks ago these were occasional. They are now near-daily, and their severity has increased in a pattern that concerns me."

"Is there anything you haven't tried?" Rachel asked, leaning forward. "Anything from the archive, anything theoretical, even if it's untested. I don't care how experimental."

The technician exchanged a glance with Ar before answering, careful. "There are theoretical interventions. Stabilization approaches drawn from unrelated medical disciplines, adapted speculatively to a condition none of them were designed for. I want to be honest that attempting them carries its own risk — we would, in effect, be experimenting on the only living case we have ever had the opportunity to study, with no way to predict how his body will respond to techniques built for entirely different problems." She looked at Xavier directly, something gentle and apologetic in her expression. "I would not recommend this path unless the alternative becomes clearly worse. I say that as someone who wants very much to help you, not as someone withholding options out of caution for its own sake."

"What happens if it keeps accelerating," Darrell asked, and Xavier heard, underneath the careful, level captain's voice, something close to real fear.

The technician hesitated, glancing at Ar, who translated the hesitation itself along with the words that eventually followed. "We don't fully know. We have theoretical models, extrapolated from what little the archive preserves and what we've observed in Xavier directly, but no confirmed precedent for how this condition resolves, because no one has survived long enough with it, historically, for anyone to document an endpoint." A pause. "I would rather not speculate further than that, out of respect for accuracy. I can tell you that we are trying everything within our current understanding to slow the progression. I can also tell you that our current understanding is limited, and that I do not want to promise you a solution I cannot currently see a path toward."

Xavier sat very still through all of it, watching the faces of the people he loved absorb, piece by piece, a truth he'd already half-suspected on his own, alone, in the dark, on the nights the dizziness kept him from sleeping.

He was running out of time. Not abstractly. Actually.

Rachel found him afterward, alone in the courtyard, staring up at a sky he still hadn't fully learned to read, and sat down beside him without asking permission, which he'd come, over the past weeks, to understand as its own kind of kindness — nobody asking if he wanted company anymore, just quietly providing it and letting him decide whether to use it.

"I keep thinking about the Silex Sxar," he said, before she could say anything. "Doing the math on it. Months, Rachel. That's what you said. And I don't know if I have months, the way this is going."

"Don't do that to yourself," Rachel said, gently. "You don't know that either. Nobody does."

"I know enough." He looked at his own hands, steady for the moment, though he'd learned not to trust the steadiness anymore, not to believe it would hold. "I keep thinking, if the window comes and I'm not — if I can't make it, if this gets bad enough that I'm not able to travel, not able to survive whatever the trip actually does to a body — I don't want to be the reason the rest of you don't get to go. If you want to go. If that's what you decide."

"Xavier."

"I mean it. I've been turning it over, and I don't have an answer yet, about what I actually want. Some days I think about Priya, about never knowing, about dying four million years and one impossible distance from ever finding out if I have a kid somewhere in the world, and I want to fight for every scrap of time I've got left to try to get back and find out. Other days—" He stopped, throat tight. "Other days I think about how tired I am, Rachel. How much of what's left of me is just managing fear now, managing the next dizzy spell, the next bad hand, and I wonder if the kindest thing might just be to stop fighting the not-knowing and let myself rest, wherever I end up resting."

Rachel didn't say anything for a long moment, and when she did, her voice had gone rough. "You don't have to decide that today. You don't have to decide it alone, either, whenever you do."

"I know." He managed something that wasn't quite a smile. "Doesn't make the thinking about it stop, though."

"For what it's worth," Rachel said, "I don't think wanting to rest makes you weaker than wanting to fight. I think both of those are just honest. I think you're allowed to feel both in the same afternoon and not owe anybody a tidy answer about which one wins."

"That's generous of you."

"It's not generosity. It's just true." She looked over at him, steady. "I've watched you carry this since the observation module, ninety-three days into a mission none of us knew was about to become this. You've never once made it about anyone but yourself needing to know, needing an answer, needing to finish something you started. I don't think that's selfish. I think that's just what it looks like to love somebody you might never get the chance to meet."

Xavier felt something in his chest loosen, slightly, at that — not comfort exactly, but the specific relief of being seen clearly by someone who wasn't trying to fix him, only to sit beside him in the not-knowing.

That night, the episode came harder than any before it.

He woke William first, the way he always did now, some instinct pulling him toward the person who slept lightest and reacted fastest, and by the time William had gotten the lights up, Xavier's whole left side had gone numb in a way none of the previous episodes had matched, his vision swimming, his words, when he tried to speak, coming out slurred and wrong in his own ears.

"Darrell!" William's voice, sharp, frightened in a way Xavier had never heard from him before, not even in the airlock, not even standing over the skull. "Darrell, now, I need you now—"

The room filled quickly after that — Darrell first, then Rachel, then Ar, summoned somehow in the space of minutes that Xavier experienced only in fragments, the world tilting and swimming and refusing to hold still, voices arriving distorted and distant even as hands, familiar hands, steadied him, held him, kept him from the floor.

"Stay with us," Darrell was saying, close to his ear, his voice cracking with an urgency Xavier had only ever heard him direct at instruments, at systems, never before at a person. "Xavier, stay with me, you hear me? Stay with us."

He wanted to answer. He understood, distantly, that he was trying to answer, that some part of his mind was forming words even as his mouth failed to produce them, and the last clear thought he managed to hold onto, before the room finally, mercifully, went dark around the edges, was Priya's voice, warped and distant across four million years and one unfinished sentence — I might already— — followed, close behind it, by his own quiet, desperate hope that whatever came next, he'd get the chance to find out how that sentence ended.

He woke in the medical facility, hours later by the light through the window, to the sight of all three of them still there — Darrell asleep upright in a chair that clearly hadn't been built for sleeping in, William sitting close by the bed with his head in his hands, Rachel standing at the window, watching the sky with an exhaustion that told Xavier she hadn't slept at all.

"Hey," he managed, his voice a rough whisper.

William's head came up fast, and something in his face broke open with relief so total it was almost painful to watch. "Hey yourself," he said, voice thick. "You scared the hell out of us. Don't do that again."

"I'll work on it." The words came easier than he expected, though his left hand, resting on the blanket, still carried a faint tremor that hadn't fully released him. "What did they say?"

Darrell was awake now too, leaning forward, his face carrying the specific exhaustion of a man who'd spent hours bracing for the worst. "They're calling it an escalation event. Their words, not mine. They stabilized you, but Xavier — they're recommending you don't leave this facility again without close monitoring. Not until they understand more about what's happening."

"How long was I out?"

"Almost six hours," William said, quiet. "Longest one yet. Longer than anything before it by a wide margin." He didn't try to soften it, and Xavier found himself grateful for that, for the plain, unflinching honesty of a friend who'd apparently decided somewhere in those six hours that comforting lies weren't going to help either of them anymore.

Xavier absorbed that in silence, understanding, without needing anyone to say it plainly, what it actually meant — that whatever time he had left to make his own choices, to weigh his own future, had just gotten narrower, faster than he'd braced for."Rachel," he said, quietly. "The Silex Sxar. If the window comes and I can't travel—"

"We're not having that conversation right now," Rachel said, firm, though her voice shook slightly on the words. "Right now you're going to rest, and we're going to be here, and whatever decisions need making, we'll make them together, when we have to and not a moment before."

Xavier nodded, too tired to argue, and closed his eyes again, listening to the quiet, worried breathing of the three people who had, somewhere across ninety-three days and one impossible jump through time, become the only family he had left in any world he currently occupied.

He thought about Priya, and the sentence that never finished, and understood, drifting back toward sleep, that whatever came next — however much time he actually had, however the choice eventually resolved itself — he wasn't going to spend what was left of it pretending he wasn't afraid.

He was afraid. He let himself be afraid, finally, without trying to manage it into something smaller.

It didn't fix anything. But it felt, somehow, like the first honest thing he'd done in days.