The engineers used the transportation from one of those old cities—a romantic system of canals and boats called gondolas—as a model for our public transit down here. Of course, our gondolas are modernized—they have engines and run on tracks through dry concrete canals. The people of Atlantia love the gondolas although they require constant maintenance. Even though workers repair the gondolas each night after curfew, it’s not uncommon to see a boat beached off its track during the day, machinists swarming around like mermaids gathering about the hulls of shipwrecks in pre-Divide illustrations.

My mother found the architecture of Atlantia fascinating, and she loved the trees and the gondolas almost as much as she loved the temple. “Flourishes in the face of death,” she told Bay and me once as we looked at the diagrams. “The engineers left their signature in every working of Atlantia. They made the city useful and beautiful.”

“It’s a second kind of immortality,” Bay said. “They live on in heaven, and in Atlantia herself.”

My mother looked over at Bay, and their love of the city was so palpable that I felt left out. I loved Atlantia, but not the way they did.

These lower areas have less embellishment and look more utilitarian than some of the other parts of Atlantia. Here, the rivets are clearly visible on the walls, and the sky is lower. Up at the temple, the soaring rises inside the building echo the high arches of the false sky outside.

I pass by one of the stalls that sells masks. They aren’t the air masks we carry strapped over our backs—the ones we’re told to keep with us at all times in case of a breach in Atlantia’s walls. The masks sold in the deepmarket are designed to be worn for fun, so you can pretend to be someone else. I feign interest in them, touching the faces of fantastic creatures that used to live in the Above—lions, tigers, horses—all of them known to me only from pictures in books. There are also more fanciful masks—a variety of sea witches, some with green faces, some blue.

Children delight in telling one another stories about the sea witches. We talked about them at school and when we played together in the plazas. Once, when my mother wanted me to come with her to the temple for a late service and I didn’t want to go, I tried to use what I’d heard as an excuse. “If I go out near the dimming time a sea witch might get me,” I told my mother. “Or a siren.”

“Sea witches are an old superstition,” my mother said. She didn’t deny the existence of sirens—people, usually women, who can use their voices to convince others to do their bidding—because everyone knows sirens exist. They were the first miracle that came about after the Divide. They were born to the younger generation of those who came Below, and they have been serving Atlantia ever since.

I am a siren.

It is a secret my mother decided to keep because sirens’ lives are consecrated to the service of Atlantia, and siren children are given to the Council to raise. My mother didn’t want to give me up.

“Sea witches are real,” I told my mother. “They have names.” Maybe, I thought, people know when they’re sea witches, but they keep it a secret, the way I keep my secret about being a siren. The thought thrilled me.

“And what are the witches’ names?” my mother asked in the amused voice I loved, the one that meant she was willing to go along with my game.

“Maire,” I said, thinking of a story I’d heard the day before at school. “One of them is named Maire.”

“What did you say?” My mother sounded shocked.

“Maire,” I said. “She’s a sea witch and a siren. She has magic, more than just her voice. She gets what she wants from you and then she turns you into sea foam before your family even has a chance to bring your body to the floodgates.” One of the girls at school told me that Maire drank the foam, but I decided to spare my mother this gory detail since her hands had gone to her mouth and her eyes were wide. Too wide. She wasn’t pretending to be horrified. She was horrified, and my mother was not easily shocked.

“Don’t tell that story anymore,” she said. Her voice trembled and I felt sorry. Perhaps I’d used too much of my voice in telling the story. I hadn’t meant to frighten her.

“I won’t,” I said. “I promise.”

Some people said that sirens didn’t have souls, and so I asked my mother if that were true of Maire. “No,” my mother said. “Every living thing has a soul. Maire has a soul.” And of course, my mother knew what I was really asking. “You have a soul, Rio,” she told me. “Never doubt that.”

It wasn’t until later that our mother told us the truth—that the siren Maire was her sister. Our aunt. “But we no longer speak to each other,” my mother said, a great sorrow in her voice, and Bay and I looked at each other, terrified. How could sisters grow so far apart?

“Don’t worry,” my mother said, seeing our expressions. “It won’t happen to you. They came and took Maire away when they found out she was a siren, and we weren’t raised together. We grew apart. You see? It’s one of the reasons we have to keep Rio’s secret. We don’t want her to be separated from us. We don’t want to lose her.”

Bay and I nodded. We understood perfectly.

And this was an enormous secret for my mother to keep from the Council, especially later when she became Minister. She was supposed to report to the other Council members and work with them closely. She was not supposed to have secrets from them.

But she did have secrets. At least one, and maybe more.

It was on Maire’s doorstep that they found my mother the night she died. She went to see her sister, but I don’t know why.

I’ve made it to the edge of the deepmarket, where they keep the swimming lanes—several heavy cement canals once used for the gondolas. Years ago, some enterprising group hauled the lanes down here and set them up for racing. It must have been difficult to move something so heavy.

Aldo, the man who organizes the races, nods to me as I approach. “I heard your sister went Above,” he calls out. “I’m sorry to hear that.” Aldo is a few years older than Bay and me. Even though his blue eyes and dark curly hair and smooth features should make him handsome, they don’t.

“Thank you.” Those two words are all I can manage to say without emotion when people offer me their condolences.