I walk my housemates through the code. The first section, the blue-whale song, is an algorithm for decrypting the second section, which is the actual message. The third section provides phonetic clues that tell us the language used in that message: Bundeli, a derivation of Hindi, which happens to be my ancestral tongue and the native dialect of Captain Nemo.

“Wow.” Halimah nods appreciatively. “Nice work, Ana.”

“No kidding,” Virgil says. “I thought I was going to go crazy if we listened to that recording one more time. I wish I had your ear.”

I try not to feel too pleased with myself. “I just put together what you guys did. Jack, can you—?”

Jack’s mouth is full of peanut-butter sandwich, but he starts scribbling, translating the coded message into English.

He hands the notepad to Lee-Ann to read.

She clears her throat dramatically. “And the winner is…‘This is Lincoln Base. Identify. Five hours.’”

Halimah frowns. “That was a lot of work for a really short message.”

“Île Lincoln,” Gem chimes in. “That’s what Harding and Pencroft named the island where they were stranded.”

The Dolphins turn and stare at him.

“What?” he asks. “I read The Mysterious Island, too.”

I study the LOCUS display. It’s still riddled with purple blotches like the pattern from a shotgun blast. My nerves tingle. Our situation finally starts to feel real. We’re getting close to the island of Captain Nemo…. The place where my parents died.

“Identify.” Lee-Ann drums her fingers on the table. “That part is clear enough. They want to know who we are. Five hours…Is that our time to arrival?”

“It would be two hours now,” Gem says. “You guys were working on that code for three hours.”

That seems impossible. But according to the ship’s chronometer, Gem is right. It’s one in the afternoon. I remember the coordinates I got from the supersecret map in the captain’s stateroom. I do some quick calculations based on our current course and speed.

“It’s not our ETA,” I decide. “We shouldn’t arrive at the island until seven p.m. The five-hour thing is an ultimatum. We need to figure out how to answer this challenge. And we need to do it in the next two hours.”

Virgil gulps. “And if we don’t respond in time, or respond the right way?”

“Then,” I say, “I imagine our own secret base will blow us out of the water.”

Chapter Twenty-Four

But no pressure.

It’s one thing to decrypt a message. It’s much harder to figure out the correct answer and say it back in the same code. And we have less than two hours to do it.