“Ahead slow,” I say. “Course corrections at your discretion.”

“Aye.” Halimah turns a lever ever so slightly.

As soon as we reach the tunnel, a tremor rattles the bridge. Bubbles cascade over the forward windows.

I grip my armrests. “What was—?”

“Explosion!” Gem yells, a little louder than necessary. “N-not close, though. That was about…” He fiddles with his controls and his holosphere changes to a deep purple color. “Whoa, that’s cool.”

“Something about an explosion?” I prompt.

“Right, sorry. There was a detonation against the north rim of the atoll, about a kilometer away. Torpedo, maybe?”

“Massive shock wave for a torpedo,” Virgil says.

“The Aronnax,” Ester says.

That name is more unsettling than the organ’s diminished chord.

I want to believe that Luca and Ophelia blew our enemies out of the water, but I know we couldn’t be that lucky. More likely the Aronnax was sending a warning shot, letting Lincoln Base know they mean business. At least the cave hasn’t collapsed on top of us yet.

“Steady as she goes,” I say.

Halimah takes us into the tunnel.

Outside the windows, the constellations of phytoplankton disappear. Only a meter above our heads, the ceiling of the lava tube slithers past, glistening in the purple glow of the bridge. Of course Nemo would make his lighting purple, I realize. The longest light waves, blue and purple, are the last colors to disappear underwater. I wonder if the Nautilus has purple headlights. Or ye olde windshield wipers.

The holospheres at all the stations suddenly flicker and die.

“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 the Aronnax?” 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. “The Nautilus feels good,” she tells me. “I think she’s excited.”

That makes one of us.