He gave a single chuckle. ‘I probably could.’

We sat quietly, again. ‘Out with it,’ I said. ‘Whatever it is.’

Chikondi exhaled. ‘Do you think it’s right for us to be here?’

‘Elaborate.’

He nodded at the rats. ‘We’re annoyed with them because they’re in our way. But they’re in their element. This is their niche, not ours.’

‘Species migrate,’ I said. ‘Most of evolutionary history can be summed up as chance encounters between species that hadn’t crossed paths before.’

‘We’re not migrating, we’re sticking our noses in. We’re not here because we need food or territory. We’re here because we want to be. We’re flipping over rocks because we’re curious.’

‘You’ve always been a guy who likes flipping over rocks.’

‘Yes, I like it. The animals underneath do not. Say there are worms under the rock. Worms hate sunlight. It hurts them. Is it fair to the worms, to cause them pain so that I can know more about them?’

‘You always put the rock back. We always put the rocks back.’

‘It still hurts before we do so. Is that a fair trade, their pain for our knowledge?’

‘If that knowledge means we can do right by the general population of these figurative worms? That we can alter our behaviours and practices so that everything in an ecosystem, worms included, won’t be harmed in the future? Yes, I think that’s a very fair trade. A sacrifice on behalf of one, or a few, to benefit the many.’

‘You can only call it sacrifice if it’s consensual. Nobody asked the worms under the rock what they thought about the whole thing.’

‘If we don’t hurt a few worms, we won’t know that worms can be hurt. That path’s got far more potential for destruction.’

‘You think so?’

‘You don’t?’

He thought silently. ‘I probably do,’ he said at last. ‘But I don’t know right now.’

I watched him as he watched the rats. ‘What are you looking forward to most about going home?’

He blinked. ‘What?’

‘Where’s the first place you’re going to go, once we’re out of quarantine?’

I’d thrown him off of his mental track, and I could see him struggling to shift gears. ‘A cafe,’ he said.

‘Huh,’ I said. ‘Any particular cafe?’

‘No,’ he said. ‘I don’t care which.’ He looked at me; I was still waiting. ‘The sort that looks like they cleaned out their grandmother’s garage and put everything they found on the walls. Comfortable chairs. Good music, but not too loud. I want a cold drink and a dessert that looks ridiculous, and I want to sit in a corner and read a book and listen to conversations I don’t understand between people I don’t know.’

I instantly understood the appeal of his last point, and did not take offense. ‘What kind of book?’

‘I . . . I don’t know.’

‘Sure you do. Come on.’

He considered. A little smile pushed at his cheeks. ‘Something with a heist.’

I laughed. ‘Since when do you read heists?’

He shrugged. ‘I don’t. Just seems like the sort of thing you read at a cafe while eating dessert.’

‘Okay,’ I said. ‘And where is this cafe? Back in Lusaka, or near campus, or someplace you’ve never been?’

‘I really don’t care,’ he said. ‘Cafes are pretty much the same wherever you go.’

‘I’d—’

My answer was cut short by the scream of a rat. Chikondi and I jumped. The sound died down within a few seconds, but Chikondi remained shaken. I looked down at the sheet and saw it gripped between his fingers, as if he might fall. I’d gotten five cumulative hours of sleep the night before; how had he fared?

I took his clenched hand within mine. He relaxed, just a touch.

Where do you want to go?

Home, I thought. But where was that, now? The Merian had fit that bill for years, but she no longer felt like home, just a machine we were trapped inside. Did I want my parents’ apartment, the one I’d grown up in? Someone else owned it now, surely, if it hadn’t been torn down. The latter was the more likely scenario, I figured. I imagined the walls of my childhood room, such a sturdy, immutable fortress then. I imagined them being torn apart by construction equipment, cheerful paint giving way to raw wood and bent nails and weary insulation, a space within a space, an impermanent dimension in the place that had been an eternal refuge.

A new home, then. I forced myself to entertain the thought, despite the headache I could not shake, a product of both the steady noise and my growing malnutrition. What kind of home did I want? A city apartment? A rural house? Did I want a place of my own, a place to set roots and settle, or would I be content to rent furnished rooms, bouncing from country to country as whim or opportunity suggested?

The rats shrieked. Thunder growled. Choppy waves smacked the hull. I gave up on the questions. I couldn’t cosy up in the future. The present was far too loud.

Please let me sleep, I thought. It was a wretched plea, transmitted in no direction in particular but asked from the bottom of my heart all the same. Please, please let me sleep.

I did not.

Elena ducked her head out of the guts of the water filtration system, a wrench in her gloved hand. ‘Do you think they could come through the hull?’ she asked.

I blinked, lowering my flashlight. ‘The hull that can withstand micrometeoroids at half the speed of light.’

‘A single impact is different than something scratching all day, every day. Could they erode the outer plating?’

‘No,’ I said, but now I didn’t know. Could they? The notion seemed ridiculous.

. . . but could they?

‘They won’t get inside,’ I reassured her, despite my lack of certainty. ‘I’m sure of it.’

‘Okay, that’s good,’ Elena said. She paused in thought. ‘Even if they don’t get in, could they damage the hull in such a way that might compromise our safety in flight?’

I stared at her. I hadn’t considered this. ‘I doubt it.’

‘But is it possible?’

‘I—’ My mind itched now, wondering what other dangerous possibilities I hadn’t thought to examine. ‘I’ll have to think about it.’

She nodded, glad that I was taking her question seriously. She continued to inspect every pipe, every wire. We’d done a full inspection like this four times in the past two months. A strange part of me wanted to find something wrong, something that would tell Elena her gut feeling had been right, something was amiss, but hey, our diligence paid off. We solved a problem before it happened. We prevented catastrophe.

Instead, we found nothing. Again.

The more nothing we found, the less she trusted it.

I had no reason to join Jack in the data lab, and would have kept walking, were it not for one muttered word:

‘Idiot.’

I stepped back and ducked my head in the door. ‘Who is?’

He hadn’t realised I was there, his expression said. He shook his head and gestured at the monitor. ‘Cubesats finished mapping the sea floor.’