We pulled more of the wall down, excavating a hole big enough to look through. There was about a foot of soft marrow behind it, and every inch of it was carpeted with corpse blooms and the things that liked to live in them: ants, beetles, creepy-crawlies.

“I’ve seen these flowers before,” Vivi said as she leaned her head into the wall, her phone flashlight revealing more of the wet space. “Growing on the dead dude who fell out of the ceiling.”

“They’re the same flowers they found in our hair when we came back,” I said. “The police tried to identify them but they couldn’t. I saw it in a file. They’re hybrids, pyrophytes.”

“Pyro-whats?” Tyler asked.

“Plants that have adapted to tolerate fire. Some of them even need fire to flourish.” I thought of the charred shell of the house in Edinburgh, the blaze so hot it left only the frame of the front door standing. The gunpowder heat of the bullet that grazed Vivi’s arm. The flames that engulfed Grey’s apartment. Heat and flame. Blood and fire. Was there a link?

Vivi pulled her head out of the wall and started rummaging in her backpack. “Here,” she said as she held out Grey’s journal, the one we’d found in her hidden apartment. We hadn’t handed these things over to the police. They felt too sacred, too personal. “The last photo and all of the sketches.”

I flicked to the middle of the journal, to the Polaroid photograph of a doorway in a ruined stone wall. It was covered in a carpet of white flowers.

Vivi pointed to the picture. “A door that used to lead somewhere,” she said as she turned the pages of the book, revealing page after page after page of sketches, each one of a different doorway, “but now leads somewhere else.”

The words felt like poetry, something I’d once known by heart but had long since forgotten. “How do I know that saying?” I asked. “What’s it from?”

“In Grey’s fairy tale, that was how you got to the . . . in-between place. The Halfway. Limbo. The land of the dead. Whatever. You walked through a door that used to lead somewhere else. A broken door.”

My memory reached for something. Yes, a story Grey had told us when we were younger. The place she spoke of was strange, broken. Time and space got snagged there, caught in snarls. “You don’t actually think that . . . she’s, what, somewhere . . . else?”

“What if the stories she told us when we were little were true?” I laughed and looked at Vivi, but she was serious. “It was a liminal world,” she said, her face close to the photograph from Bromley-by-Bow, studying the ruin. “A kind of accidental gutter. Like . . . the gap at the back of the couch that crumbs and coins fall into.” Vivi looked at me, her eyes hard as lead. “What if she’s there? What if she found a way back?”

“Vivi. Come on.”

“Yeah, I’m with . . .” Tyler glanced sideways at me. “The youngest Hollow . . . on this one.”

“Oh my God.” I narrowed my eyes at him. “You don’t even know my name!”

“We were never formally introduced!”

“It’s Iris. You dick.”

“Pleasure to make your acquaintance. You harpy.”

Vivi was ignoring us. “Do you remember what Grey used to say about missing people?” she said. “Some people go missing because they want to; some go missing because they’re taken. And then there are the others—those who go missing because they fall through a gap somewhere and can’t claw their way back.”

“The Halfway was a story,” I said.

“I know. That doesn’t mean it can’t be true.” Vivi shoved the journal back into her bag, then pulled out the brass key to Grey’s burned flat. “Something happened to us when we were kids, Iris. Something no one has been able to explain. I’m starting to think we fell through.”

“Fell through what?” I asked, but she was already striding away, toward the front door. “Vivi, fell through what?”

My sister turned and took me by the shoulders, a half-mad smile on her face. “A crack in the world.”

12

The smell of burning still drifted in the air, clinging to the tightly huddled buildings of Shoreditch. There were two piles of blackened furniture and debris stacked high on the sidewalk, covered by blue tarps and warning signs. Only the windows on Grey’s floor were boarded up, but there was blue-and-white POLICE LINE DO NOT CROSS tape across the front door. The whole building had been written off. That suited us just fine; it meant we had the place to ourselves.

We broke in through the same window we’d jumped from days before. We propped a charred but still-intact table against the wall and scrabbled up the rest of the way using some pipes as footholds. Vivi dislodged the board covering the window with a hard push. Then the three of us slipped inside like fish, Tyler protesting about the damage to his expensive clothes the whole time. The smell was stronger than I expected, the death stench overpowered now by the reek of burning chemicals, the taste of ash and poison.

It was pitch-dark with the windows boarded up. We used the flashlights on our phones to navigate what was left of the place. The bedroom, where the fire had started, was a charred shell, the skin of the room eaten away to reveal its wooden bones, now black and warped and blistered. No part of the space was recognizable. The bed frame, mattress, chair, everything had burned in the extreme heat, been reduced to shards. Much of the wall and roof plaster had been torn away by firefighters looking for any hidden snarls of flame still burning in the dark. The floor was spangled with debris.

But that wasn’t what we came here to see.

“Holy. Shit,” Vivi said as she swept her light across the space.

Everywhere, growing on almost every surface, were the death flowers, bursting from the ashes.

“What the ever-loving fuck is going on?” Tyler whispered as I plucked a bloom from where it had taken root in a withered wall beam. They clustered most thickly around the warped frame of Grey’s bedroom door, the door to the closet, the door to the en suite.