‘Halimah?’ I ask, alarmed.

‘It’s okay.’ Her left hand stays steady on the lever. Her right flits from control to control as if she’s used this console her whole life. ‘I was anticipating that.’

‘The walls of the lava tube have an exceptionally dense metal content,’ Lee-Ann tells me. ‘They’re messing with our LOCUS. We’ll have to use physical readouts until we reach the other side.’

Halimah doesn’t reply. She’s a little busy trying to keep us in one piece.

‘Tactical is down, too,’ Gem says. ‘I can’t tell what’s going on out there.’

‘Did you get a position on theAronnax?’ I ask.

‘Nothing. Maybe they’re camouflaged.’

‘That could be good,’ Ester says, feeding a bit of scone to Top. ‘Maybe they won’t be able to see us, either.’

Speaking of which …

‘Engine room, report,’ I say. ‘How are we looking?’

‘Well,’ Nelinha says, ‘the glowing things are still glowing. The humming things are still humming. I think we’re good.’

‘If we have dynamic camouflage, now would be a good time to activate it.’

‘Uh … yeah. Stand by.’

Our passage through the tunnel seems to take forever. Sweat trickles down my back. My shirt sticks to the fine Italian seaweed leather.

No one speaks. Even Top is quiet, sitting patiently at Ester’s side, waiting for more pastry bites.

Ester rests her hand on the back of my chair. ‘TheNautilusfeels good,’ she tells me. ‘I think she’s excited.’

That makes one of us.

Jack returns, out of breath from his run through the ship. ‘No problems,’ he reports.

Nelinha announces over the intercom: ‘Camouflage active, babe. I mean Captain. Captain babe.’

A moment later, the LOCUS displays flicker to life again.

‘We’re out,’ Halimah sighs.

‘Yes!’ Lee-Ann gives her a round of applause. Jack whoops and pumps his fist. From the hallway behind us, I hear the echoes of cheers from the rest of the crew.

Our enthusiasm doesn’t last.

‘Ana!’ Gem shouts, forgetting the whole ‘Captain’ thing. ‘I’ve pinpointed theAronnax.’ He turns, his expression grim. ‘That explosion? It didn’t justhitthe north side of the atoll. The north side of the atoll is gone.’

Gem flips a switch. His tactical holosphere expands, showing us a 3-D view of Lincoln Base. The main island rises from the lagoon, ringed by the atoll that used to be an almost perfect concentric circle. Now, in addition to the channel theVarunanavigated through a few days ago, there’s a much larger break in the northern rim. A section of beach and brambles the size of a soccer field has simply disappeared into the sea.

The purple blip of theNautilusglows at the southern edge of the display. Directly opposite us, to the north of the broken atoll, floats a second purple dot: theAronnax.

Weapons fire traces like shooting stars across the holosphere, back and forth between theAronnaxand the turrets along what’s left of the atoll. One after another, the island’s defences go dark.

My mouth feels full of wet sand. ‘Gem, can you zoom in on the attacker?’

He fiddles with another knob. Suddenly I am seeing theAronnaxup close and personal – or at least her holographic image.

As we saw on Dr Hewett’s fuzzy drone footage, the ship is shaped like an arrowhead – as if Land Institute retrofitted astealth bomber for underwater use. Surrounding its hull is a fuzzy violet halo that seems to be soaking up the discharges from the base’s defences.