“I need to go back,” I say.

“They’ll kill you, too,” True says. “We have to trust Maire and do what she said.”

“I don’t know if I can.”

“You have to,” True says. “It’s what she wanted. If you go back, you betray her. You need to let Maire save you.” He moves a little, readjusting his position, and then he says, his voice almost angry, “Why did you try to go up through the floodgates if Maire told you she could take you up a different way? You could have died.”

“Some of us don’t have the luxury of knowing when Maire is telling the truth.”

“But you could have trusted me,” True says. “You could have told me what you planned to do.”

“You would have tried to talk me out of it,” I say. “You might have even turned me in to the Council to try to save my life.”

True’s silent.

“I need to go back,” I say again. It is all I can do to keep my real voice from breaking through. I have to save it. Maire told me so.

Did she use her voice on me to convince me to leave her with the other sirens? Could it be that she’s done all of this just to get me to the surface?

She gave me a shell, one that holds my mother’s voice.

What if it tells me something that I desperately need to know?

I want to hear my mother speak. It has been more than a year without her, and I am afraid and Above.

I hold up the shell. I clutched it tight in my hand the whole time we swam, and suddenly I worry that time will have taken away her voice, that there will be nothing left but the sound of water and wind.

“I have to listen to this,” I tell True. “I can only hear it once.”

He looks at me like he did back at the lanes in the deepmarket, as if he doesn’t understand but is with me anyway, and nods.

I put the shell to one ear.

And then I hear her voice and my hands start to shake. True puts his hand over mine to help me hold the shell steady, but he turns his face away to let me listen in privacy.

So, she says. This is everything I have learned about the sirens and the Divide and our gods.

It’s her. It’s really her. She must have told this to Maire, and Maire saved it. How did Maire know she would need it?

The Divide did not happen exactly the way we were taught, my mother says. Her voice is not the one she used over the pulpit. It is low, urgent, intimate, the voice she used with someone she loved. Someone she trusted. Some of it happened the way we’ve been told: People were chosen for the Above and the Below. Everyone Above had someone Below who they cared about so they would keep the Below alive.

But the rest of it, the religion, came later.

The temple, the gods, all of it, was a facade, a conceit. It was a way to make things beautiful Below while evoking the old cultures of the Above. No one believed in the gods as gods. They thought they were gargoyles. Decorations.

But then the miracles began to happen.

First the sirens, and then the bats.

And then the people came to believe. They built their religion around the miracles.

You know all this.

Thank you for unlocking the door to the Council’s secret library for me. Thank you for making it so that I could read the papers. So that I could hold the evidence in my hands.

I’m sorry that I couldn’t believe in your voices in the walls.

You were right.

I should have listened to you.

Because now it may be too late.

I read other things in those papers.

Did you also know that the air Above became clean enough to live in years ago? Though still polluted, it is much more safe to live there now. But by the time this happened, the Above wanted nothing to do with us. They hated us for our sirens but loved us for the ore we could deliver. So they reached a conclusion—they would keep us alive as long as the mines kept producing.

But the mines are running out of ore.

The Council of the Below decided that the Minister always had to be a true believer, which is part of the reason they selected me. How else could I convince the people if I didn’t believe myself? And the people Below had to be convinced, had to believe their lives were wonderful and safe, so they could keep mining and keep Atlantia running so that we wouldn’t be cut off. The people of the Above have no desire to live or work in Atlantia. They think it’s dirty, broken. They think we as a people are dirty and broken, too.

We are not the only Above, and not the only Below. We are an outpost, one among many, strewn across the great islands of the sea. The cities Below were where the fortunate once lived and worked, but now the roles have been reversed.

Sirens have appeared in all the Belows. Our mines have lasted longer than anyone else. And the other Aboves have—and I cannot bear to say this—

The other Aboves have killed all their sirens. They found that it was very easy to do, because even if some of the sirens escaped the drowning of their cities, even if no one catches or kills them, they can’t survive for more than a few days Above. They belong to the Below.

What? I am so shocked that I pull the shell away from my ear, forgetting that I will lose her voice. I pull it back fast, to listen again. My heart pounds hard inside my chest.

I can’t live without the Below. I can’t live here Above. And everyone like me has been or will be killed.

I push my hand, hard, into my mouth so that I won’t scream.

We have the last sirens, my mother says, and it is a matter of time before the Above tells our Council to get rid of our sirens, too. And our Council will listen, because if they don’t, they will die. Everything they’ve done to deceive us has been to save themselves when the time comes.

So we have to save the sirens. We have to appeal to the people of the Above and the Below, so that they will see that this is wrong.

We have to save Atlantia, too. They let us send up our child-ren once a year on the anniversary of the Divide, but I don’t know how many more people the Above will allow to come up. I don’t think they care about saving all of Atlantia. Though survival is possible in the Above, the people there see us as drains on their resources, as parasites. Which we were, for many years. But as things are right now, the sirens cannot live for long outside Atlantia. They can’t last without the water above them.

Will you help me? I have to save you, and I have to save—

My mother stops. She doesn’t say my name, but I wonder if that is when Maire realized that I could be a siren. If, when I spoke in the temple, it was the confirmation of something she’d already guessed.