“Exactly,” I said. “Unless you’re the ninth sister, and have the secret to immortality. It was her all along,” I said. “I’m sure of it.”

“I thought we already crossed her off,” Anya said slowly, the pages of the book fanning open as she loosened her grip. “The ninth sister died. That’s why she hid the secret. You went to her headstone.”

“Maybe she never died.”

Anya frowned. “Then why would she have a headstone?”

“I don’t know, but everything else matches up. She was alive in the early 1700s, during the time of the Nine Sisters. She was incredibly smart, had ties to the Royal Victoria, and to salt water, from her later research in water and lakes. It fits, it all fits.”

I watched Anya work it all out in her head. When she looked up at me, her eyes were wide with wonder. “It could be. So now what?”

“We figure out where she would have hidden the first part of the riddle.”

“How?”

“She probably hid it in a place that was important to her, right? So all we need to do is find out more about Ophelia’s life.”

“But how?” Anya said, exasperated. “She could still be alive. Where do we even start?”

My mind skipped back to the last time I’d heard about Ophelia Hart. “Noah.”

We ran outside, through the snowy campus toward the boys’ dormitory. Asking one of the boys on the stoop which room was Noah’s, we raced upstairs, winding through the maze of hallways that were arranged exactly as ours were, except the wallpaper was brown. When we reached his door, I smoothed out my hair and took a breath before knocking.

“Renée?” Noah said, adjusting his glasses as his tall body filled the doorway. “I—I’m sort of busy right now—”

“I know you probably don’t want to see me right now,” I cut in. “I don’t blame you. But we found her,” I whispered. “We found the ninth sister. And we need your help.”

Noah went rigid as he took in what I had just said. And glancing over my shoulder at Anya, he pushed his door open. “Come in.”

And just like that, we became friends again.

Noah’s father had an office in the history building at the university. “There’s an entire library of archives in the basement; I go down there with my dad when I help him do research. They have stuff going all the way back to the founding of Montreal.”

So the three of us piled into a taxi and set off. I turned around and stared out the rear window as we wound through the city, my eyes glued to the sidewalks, searching for any sign of the Undead. Even though the streets were empty and motionless, something about the pressure of the air made me nervous.

The university campus was white and slushy as we ran through it, the quadrangles peppered with statues sculpted out of a dark bronze.

“Do you feel that?” I said, slowing to a jog as a prickling sensation climbed up my legs, as though a cool wisp had wrapped itself around me.

“It was probably just the specimens in the biology lab,” Noah said, glancing at the building to our right. “Come on.”

But it wasn’t just the biology lab. It was a familiar feeling; the kind of chill that made the air seem thinner, staler, as if it were rearranging itself into a path.

“Come on,” Noah said. “We’re almost there.”

But just as I started walking, I saw a flash of white. And then again.

“There,” I said, pointing to the thicket of trees. “They were right there.”

If Anya and Noah heard me, they didn’t let on.

I slowed, letting them walk ahead, and quietly, I approached the statue. “Dante?” I whispered, hoping it was him I had felt, though the cold, odorless air told me it wasn’t. I blinked into the night.

Someone laughed behind me; a child. I whipped around, but no one was there.

“Renée?” Noah shouted from up the path.

Before I could respond, two boys, short and pale, emerged from the trees, their faces round and chubby. They ran toward me from either side, their bodies so light they didn’t even sink into the snow. “No,” I whispered, but the words never left my mouth. And then they were touching me, grabbing at my legs, my skirt, my coat.

Jerking around, I flung them off, the shadows parted, and a thin figure stepped through the air, his face a streak of white against the sky. My breath got caught in my lungs as I fell backward, staring at his limbs, long and stiff like a scarecrow’s.

I tried to stand up, but the two boys were grasping at my arms, pressing me deeper into the snow. But as I struggled, my fingers digging into the ice, all I could think of was Dante; of how I wished I could see him one last time.

And then I heard a girl’s voice whisper in Latin. It was so soft, I could barely hear it, but slowly, the Undead around me seemed to become calm, their grips weakening until they slinked back, retreating into the shadows.

“Go,” she said to me, in a voice I recognized.

“Anya?” I whispered, as she pulled me up.

“Go!”

Before I knew it, I was running, Noah by my side.

“What about Anya?” I said, looking wildly behind me, but Noah pulled me on.

“She’s fine,” he said. “She’s taking care of it.” Grabbing my wrist, he led me off the campus to the street, where he hailed a taxi. It screeched to the curb.

“We can’t just leave her,” I said, but Noah took my hand and pulled me in, slamming the door behind us.

“Drive,” Noah said over the front seat.

“What are you doing?” I demanded. “Anya is back there, alone.”

“She’s fine.”

“How do you know?” I said, incredulous. “Haven’t you seen her in class? She can’t take them on her own.”

“She can,” Noah said firmly. “She’s a Whisperer. A rare kind of Monitor. One that can speak to the Undead; persuade them, manipulate them.”

“What?” I said, confused.

“Didn’t you hear her just now? She was speaking to them. She has it under control. They’re looking for you, anyway, not her. We can lead them away from her. So focus. Where should we go?”

I glanced out the rear window at the pale children in the distance. “Île des Soeurs,” I blurted out, before I realized what I was saying. The taxi slowed, and with a jolt, we made a sharp right turn.

As we wound through the Montreal streets, I wiped the water and dirt from my face and caught my breath. Every so often I glanced through the rearview mirror, expecting to see flashes of white trailing behind us, but the streets were empty. I don’t know why I had an impulse to go to the Île des Soeurs. Maybe it was because the convent on the island was the one place the Undead feared, though I hadn’t thought of that till after. No, it was a feeling I had, a feeling I hoped I could trust.

We drove until we reached a long bridge leading over the St. Lawrence River. On the other side was a tiny island pinpricked with trees.

“Can you drop us at the convent?” I said to the driver. He nodded beneath his cap.

Île des Soeurs was a small island with neat rows of houses, the glow of televisions flickering through the windows. Driving through the streets, I felt somehow calmed, as if everything here were visible. The driver parked in front of a gated building that looked like a junkyard. The sidewalk was covered with loose trash and scraps.

“This is it?” I said as a gray cat darted out from behind a garbage bin and scampered across the road.

“Yep,” the man said.

We paid him, and the rumble of his car’s muffler faded away into the distance. Behind us, the setting sun was bleeding red all over the St. Lawrence River. Pulling up my scarf, I ran toward the plain rectangular building looming behind the iron gates. It was cream with brown trim and thin bars over the windows.

Parked in its driveway, hidden in the shadows, was a gray Peugeot.

“It can’t be,” I said. “It’s the same one I saw Miss LaBarge in a few months ago.”

“Come on,” Noah said, and led me to the tall gates. The iron bars twisted and coiled toward the center to form the words: couvent des soeurs. In the middle of the gates, the bars were lashed together with a chain, and locked.

“Do you think she’s in there?” I said.

As if in answer to my question, a light turned on in one of the windows on the third floor. I jumped, bumping into Noah, who caught my arm.

“There’s only one way to find out,” he said.

Before I knew what was happening, Noah grabbed the top rung, and in an elegant swoop, lifted himself up and over the gate, landing on the other side.

Wiping his hands on his pants, he let out a breath and stood up. “Now you.”

He braced himself to help me climb up, but instead, I grabbed the bars and stuck one leg through, and then another, contorting my body until I had squeezed through to the other side.

There were stray cats everywhere. Creeping between the crevices of the foundation, crouching beneath the bushes, peering out from underneath the front stoop as we approached the front door.

“Are you just going to knock on the door?” I asked.

“Do you have a better idea?”

I didn’t, but something about it made me feel uneasy. A cat darted across the lawn in front of my feet. I covered my mouth before the gasp came out.

Noah took my hand and squeezed it, and together we climbed up the steps. I braced myself against the railing as Noah pressed the bell.

Somewhere inside, a chime sounded, but no one came to the door. A calico cat rubbed its head against my ankle; I nudged it away. Just as Noah held his finger up to the buzzer again, we heard footsteps thud inside. The sound of locks being unlatched. And then the knob turning.

The door opened a crack, and a woman appeared, peeking through the chain bolt. She was holding a shovel, its tip pointed at us through the gap. The foyer behind her was dark.

When I saw her face, I froze. “Miss LaBarge?”