I try to process this information. I can recall several times over the last two years when Dev seemed inexplicably angry.Then again, we’d lost our parents. I wasn’t a happy camper, either.

I have no trouble imagining Dev being impatient to see theNautilus. The idea that he would listen to reason and go quietly off to college, though … that’s a little harder to picture. Sure, he acted excited about graduating. He was looking forward to college. But, now that I know about theNautilus, I wonder if Dev was secretly chafing about those extra four years of waiting.

I wish I could have talked to him about it. Now it’s too late.

‘You should play,’ Ester suggests. ‘I think the ship would like that.’

Like another language …

Still standing, I place my fingers on the lowest keyboard. The keys are as cold as air-conditioner vents.

It’s been years since I played … since just after my parents died, when our house was sold, and the old piano was rolled away. Do I even remember any songs?

I decide to try Bach’s Fugue in D Minor. That was written for the organ. I used to play it every Halloween, because it was so creepy. Played at a slow pace, it’s also plaintive and sad, and the composition is so old Nemo might have known it. He might have even played it on this organ.

I peck out the first measure. The notes sound flat, but they resonate through the ship.

Second measure: I miss a beat, hit a D-natural by mistake, but I keep playing. The arpeggio brings me to the first full chord. I let it play out, shaking the floor. I lift my hands. I am trying to recall the next measure when Nelinha says, ‘Ana.’

I turn. Luca and Ophelia are staring in amazement at the lights that have come to life on the bridge. The control panels are all illuminated. Four LOCUS holographic displays float above the control stations like a line of ghostly planets. Thegreat eyes of the prow are lit purple around the borders. The captain’s chair has similar mood lighting around the base.

TheNautilus, it seems, likes Bach.

‘Ana Dakkar,’ Luca says in a reverent tone, ‘today is going to be a wonderful day.’

When Luca sayswonderful, he meansso busy you will never sit down.

The rest of the morning, I lead tours of theNautilusfor my classmates, taking only a few at a time. Before each visit, I talk to theNautilusto let her know what’s up. Ester serves as submarine interpreter, warning everyone to be considerate of the ship’s feelings. I’m not sure what our classmates think of this, but they are willing to humour us. Top tags along, sniffing everything.

By lunchtime, the entire freshman class has been on board at least once. We’re all left smelling faintly of mildew and vanilla air freshener. On the plus side, no one has been killed by electrical discharges or mould allergies. I consider that a win.

We all gather to eat in the dining room of Lincoln Base, but I’m so frazzled I can barely enjoy Jupiter’s excellent macroalgae-cheese soufflé. Most of my classmates seem to be in great spirits, though. They feel safe, shielded from the outside world by our HP mentors and lots of alt-tech gadgetry. They’ve had a few good meals. TheNautiluswoke up more easily than anyone anticipated. What’s not to feel happy about?

The crew even feels excited about Luca’s plans to put us towork after lunch. Twenty people can clean a lot faster than one or two. If theNautiluslets us, we will immediately start hauling out the mouldy furniture, un-gooping the internal wiring and ductwork, and scrubbing … well, everything. To me, it feels like that scene inTom Sawyerwhere Tom convinces all his friends to pay him for the fun and privilege of painting his fence, but I guess it’ll get the job done.

The news from the sickbay is also encouraging. Though Dr Hewett remains comatose, his condition has stabilized thanks to experimental medicines Ophelia reverse-engineered from theNautilus’s own laboratory.

I ask her privately if she has anything for menstrual cramps. Mine have passed for now, but periods are like General Douglas MacArthur in World War II:They shall return.

Ophelia sighs. ‘If Nemo had been a woman? That would have been thefirstthing he invented. But, alas, no. Just general pain-relief medication. Once the submarine is back to full operations, we will ask her to help us engineer something more specific, yes?’

During lunch, the only person who looks unhappy is Gemini Twain. He sits across from me at the dining table, glumly poking his soufflé with a fork.

‘Okay, there, Spidey?’ Nelinha asks him.

Gem frowns. ‘You all shouldn’t have gone on board the sub without me this morning. What if something bad had happened?’

‘Well,’ Nelinha says, ‘I’m sure you would have shot the submarine right between the eyes like a true hero! Fortunately, we survived fine without you.’

Gem stares at the table, as if he’s saying a prayer for patience. ‘I’m going to check on Dr Hewett.’

He stands and marches off.

I put a hand on Nelinha’s wrist. ‘We don’t need to be sniping at one another.’

She looks surprised. ‘Whatsniping?’

I sigh, get up and follow Gem.