‘It doesn’t matter right now,’ I say. ‘In less than a minute, they’ll have a direct line of fire. I need options.’

‘There’s the skiff,’ Gem says. ‘I could pilot it out, maybe draw their fire and buy you time. If I can get close enough to theAronnaxwith conventional weapons –’

‘No, that’s suicide,’ I tell him. ‘Do we have any shieldy things?’

‘Shieldy things …’ Gem frowns at his console. ‘Um, I don’t –’

‘Nautilus.’ The voice booms from our speakers so loudly I jump. ‘THIS IS THEARONNAX.SURRENDER OR BE DESTROYED.’

I recognize that voice. It’s our old friend/interrogation subject Caleb South.

‘How is this guy back?’ Gem grumbles. ‘I thought Land Institute punished failure.’

‘He must have come up with a really good lie,’ Lee-Ann speculates. ‘Maybe put all the blame on his classmates.’

‘Bah,’ Gem says. ‘I should’ve poked holes in his pink-ducky water wings.’

‘YOU’RE MOTIONLESS AND DEFENCELESS IN THAT PIECE OF JUNK,’ Caleb continues. ‘GIVE UP NOW, AND WE’LL SPARE YOUR BASE.’

TheNautilusshudders. I don’t think she likes being called junk.

‘Can we turn off his voice?’ I ask. ‘How is he even broadcasting over our comm?’

‘I – I’m looking,’ Virgil says, frantically turning dials.

Caleb’s tirade continues at a lower volume: ‘All we want is theNautilusand Ana Dakkar. None of you will be harmed. We’ll treat you better than you treated me.’

‘They’re closing,’ Gem tells me. ‘One kilometre out now.’

The island’s defences continue to fire, trying to draw theAronnax’s attention. Our enemy ignores the barrage. They are locked on us, almost as if …

A cramp hits my gut, folding my insides into various origami shapes.

‘They were never tracking theVaruna,’ I realize. ‘They were trackingme.’

‘How?’ asks Lee-Ann. ‘Is your DNA radioactive or something?’

Over the comm, Nelinha says, ‘Captain, we’ve got an idea. You’re going to hate it, but –’

‘If you don’t trust me,’ Caleb South interrupts, ‘listen to our captain.’

I shoot to my feet. ‘Shut off that stupid transmission!’ I yell at Virgil.

Then the enemy captain’s voice comes over the intercom and knocks me right back into my chair.

‘Hey, sis,’ says Dev. ‘You did a great job. But now it’s time to give up.’

I remember the first time I got nitrogen narcosis.

My instructor took me below a hundred feet with regular air tanks, just to show me what ‘rapture of the deep’ felt like. My vision started to tunnel. I couldn’t do simple calculations on my dive computer. I was filled with a strange mixture of euphoria and terror. I knew the beautiful blue void would kill me if I swam any deeper, but that’s exactly what I wanted to do.

Hearing Dev’s voice makes me feel the same way.

My thoughts turn to syrup. My brother is alive. My brother is a traitor.

I’m relieved. I’m horrified. I’m spiralling into a blue abyss.

‘This is impossible,’ I say.