‘Your class,’ I say. ‘Theoretical Marine Science. All the bizarre, dangerous tech you talked about. It isn’t theoretical at all, is it?’

He gives me that sad expression again. ‘Oh, my dear, I am so sorry.’

This apology scares me worse than anything he could have said. Andmy dear? He’s only ever called me Prefect Dakkar (my correct title), or Miss Dakkar (which I hate), or sometimeshey, youif he’s feeling particularly perky.

It seems dangerous to keep asking questions. It feels like I’m standing on the highest cliff I’ve ever dived from. I take the plunge anyway. ‘You said Jules Vernereporteda few things correctly. You didn’t say heforesaworimagined. Are you telling us the events in those novels actually happened?’

Hewett sets down his Leyden gun. His fingertips linger over the elaborate wiring on the barrel. ‘The age-old question: where do authors get their ideas? In the case of Verne, the answer was personal interviews. He heard rumours. He sought eyewitnesses.Those witnesses lied to him about certain details to protect themselves. Verne changed other facts to make his stories read like, well,stories. But yes, my dear, the bulk of those tales is true.’

A fragile silence descends on the bridge. The only sounds are the hum of the engines and the thump of waves breaking on the prow. The other prefects look dazed. When Hewett talks again, they lean in, as if trying to hear a voice from a century-old phonograph.

‘Since the school’s founding,’ he says, ‘we have been able to reproduce some of Nemo’s alt-tech. Much of it we still do not understand. The mission of Harding-Pencroft is to safeguard his legacy, keep his technology out of the hands of human society, and thwart Land Institute, which would use alt-tech to dominate the world. I’m afraid, as of today, the balance of power that has existed between our schools for nearly a hundred and fifty years has been broken. Land Institute is on the verge of final victory.’

I study Dr Hewett’s aggrieved expression. My nerves feel like a shoal of herring all swimming frantically in different directions. Finally, I can’t contain the chaos any more. I burst out laughing.

I must look like I’ve gone crazy. I can’t help it. My life has been upendedagain. I’ve lost my brother, my school, my future. I’ve been running on adrenalin for hours. And we’re talking about Captain Nemo!

I hug my ribs. I wheeze and blink away the tears. I’m pretty sure that when I stop laughing, I’ll cry myself to death. Franklin steps towards me. He must sense I’m near a breakdown. Even Gem and Tia look worried.

Hewett’s eyes remain as dark as squid ink. ‘I’m sorry, Miss Dakkar.’

‘Prefect,’ I correct him, though it’s hard to come across as serious when I’m wheezing hysterically.

Hewett frowns. ‘I wish we had more time. We spent almosta year slowly orienting your brother. He was being trained to lead, to take over where your parents left off. As much promise as he showed, the pressure nearly destroyed him. Now, I’m afraid I have to ask evenmoreof you. I wish –’

He’s interrupted by adingfrom his tablet computer. I’ve never heard it make any sound before, and despite the cheerful noise I can tell from Hewett’s expression it isn’t good news.

‘They’ve found us,’ he announces.

Gem’s hands gravitate to his sidearms. ‘Is it the thing I saw on your screen before? Whatwasthat?’

‘No time,’ Hewett says. ‘Alert the crew. We’re under attack!’

They literally erupt from the sea.

I have time to yell ‘Incoming!’ before scuba divers rocket to the surface on our starboard side, all on kickboard-size DPVs – diver propulsion vehicles – moving at twelve knots or more, faster than any I’ve ever seen. I register eight hostiles, some carrying strange silvery weapons that look like harpoon guns, others brandishing … Wait, are thosegrenade launchers?

Two fist-size metal canisters plunk onto our gangway and roll hissing and steaming across the deck.

‘Flash bangs!’ Gem yells.

I shut my eyes and cover my ears, but the explosions still leave my head ringing. For a moment, I can only stagger in a daze through plumes of blue smoke. By the time my crewmates and I have recovered from our confusion, our enemies have fastened grappling hooks to the starboard rail, discarded their DPVs and oxygen tanks, and begun climbing over our gunwale like they’ve been practising this assault for months.

Eloise and Cooper are the first to return fire. They spray our attackers with their M4A1s, but it’s like they’re shooting wax bullets. The rounds make smoking white impact points againstour enemies’ wetsuits, making them flinch but causing no visible damage.

Two hostiles fire their silver weapons. Miniature harpoons impale Eloise’s shoulder and Cooper’s leg. White arcs of electricity blossom from the projectiles, and both Sharks crumple.

I scream in rage. My friends closest to starboard, most still unarmed, charge the intruders. It’s a desperate move, but a melee with armed opponents is better than getting shot down one by one, and we seem to have numbers on our side. I want to join them – I want to take apart these attackers with my bare hands for the destruction of my school, for Dev – but Gem holds me back.

‘Fire if you see an opening.’ He hands me a Leyden gun. ‘Butstay behind me, please.’ I bristle at his demeaning orders but obey as he yells to his remaining housemates. ‘Dru, Kiya!’

He tosses them each a gun from his gold-level case like he’s Militia Santa Claus. ‘Point and shoot!’

Perfect instructions for a Shark.

Two more attackers are just climbing over the rail. Gem makes them pay for their late arrival by shooting both of them centre mass. They topple backwards, flickering like defective Christmas lights until they hit the water. Maybe their wetsuits will keep them afloat. Maybe they’ll come to before they drown. At the moment, that’s not my biggest concern.

Dru Cardenas shoots another intruder. Unfortunately, the electricity also arcs to Nelinha, who had been in the process of pummelling said intruder with a socket wrench. Both of them go down.