Daughter of the Deep(38)

I’m about to protest that they are being impossibly morbid, when the fireworks explode overhead …

I wake in my bunk. Judging from the angle of the sunlight through the windows, I’ve slept through the whole evening and night.

My whole body aches, and my skull is throbbing. Ester and Nelinha are nowhere to be seen. They must have wanted to give me the chance to sleep in.

Dying is nothing to be embarrassed about. It happens to everyone.

Oh, Mom …

I couldn’t even honour her wish. We had no ashes to sprinkle in any lake. Now I have nothing but my mother’s pearl. Even getting that back was a miracle. It was delivered to us by the school, with deepest condolences – the only thing they could retrieve after the ‘accident’.

I’m tempted to lie in my bed and wallow in misery, but I know that would only make things worse. I’ve found out the hard way that with grief, like with menstrual cramps, I just need to keep moving. And today’s the day we’re supposed to reach the secret base. If there is such a thing …

I get myself cleaned up and dressed. No shower. We’re rationing water. Breakfast is a seaweed protein bar. We’re rationing food, too.

Finally, I arrive on the bridge.

Nobody gives me a hard time for showing up late. Still, I feel guilty. With our supplies dwindling, the tension on board is as charged as a Leyden gun. For the sake of the crew, I need to be operating at a hundred percent. Or at least to pretend that I am.

Our challenge arrives at 10:00 a.m., sharp.

The LOCUS display lights up with a swarm of purple splotches.

‘Aircraft!’ yells Jack Wu. ‘Wait. No … What are those?’

The purple blobs flicker in and out, changing shape and intensity. On the LOCUS, they appear to be aerial objects, hovering directly in front of the Varuna, but when I look out of the forward windows, there’s nothing but open water all the way to the horizon.

Jack senses the answer before I do. He’s the best in House Dolphin at this kind of thing.

‘Those aren’t physical objects,’ he realizes. ‘See how the blobs are flattening into waves?’

I nod. ‘Clever.’

‘What?’ Dru Cardenas demands, his voice jumpy. ‘Are we under attack?’

He looks like he desperately wants to shoot something with his shiny new Leyden cannon. Even by Shark standards, Dru is trigger-happy. I decide I should give him a task that does not involve weapons.

‘There’s no attack,’ I assure him. ‘At least, not yet. Would you round up the other Dolphins and bring them to the bridge, please? We’ve got a code to break.’

A few minutes later, Virgil stumbles in, groggy and squinting from working the graveyard shift. Lee-Ann and Halimah follow on his heels. By the time all five of us are together, Jack and I have identified the break where the pattern starts repeating. We have also discovered how to feed the LOCUS’s electrical impulses into the bridge’s speakers, converting the glowing purple squiggles into sounds.

Halimah tilts her head. ‘Blue whale?’

‘Partly,’ I say. ‘But it’s more complicated than that. Keep listening.’

HP has used blue-whale song as a code for years. The pitches, sweeps and lengths of tone can be pegged to components of human languages, making a multilayered form of encryption that is almost impossible to break if you don’t know the key.

But this code is more complicated still.

After a few seconds, the pattern changes. A series of clicks like a dolphin coda overlays the whale song. Two seconds later, the clicks and song are replaced by tones like wind through a conch horn.

Then the pattern repeats.

‘The sender knows HP encryption methods,’ Jack ventures. ‘They must assume we have a LOCUS to receive their transmission.’

‘That’s good, right?’ Lee-Ann says. ‘It must be from our base.’

‘Unless it’s a trap,’ Virgil says. ‘If this is from the Aronnax, and we reply …’

That’s a fun thought.

I find myself shaking my head. ‘No. This must be the base. We were expecting a challenge –’

‘We were?’ asks Halimah.

I tell them about Ester’s warning from last night. ‘So if this is the challenge, and we don’t respond, that will not be good. Either way, we need to decipher the code. Then we can decide what to do.’

My housemates visibly relax. Deciphering a code … that is a challenge we can tackle. It’s what Dolphins train for.

‘Let’s assume the first part is blue whale.’ Jack whips out his pencil and notepad. He starts sketching the purple blobs and waves. He says he thinks better when he’s working by hand, and since he’s our best codebreaker I never argue. ‘That second part, with the clicks … Can we slow that down?’

‘Uh …’ I’m no Cephalopod, but after a few minutes of tinkering, I manage to replay the transmission at one-quarter speed, which makes the pattern clear. ‘That’s five by five.’

I don’t realize Gem is standing behind me until he asks, ‘What’s five by five?’

I almost jump out of my socks. Seriously, I’m going to have to put bells on his holsters so he can’t sneak up on me like that.

‘It’s like Morse code,’ I explain. ‘But different. In the Vietnam War, prisoners of war used it to tap out messages to one another.’