My sister, the stranger.

She was everywhere. She would always be everywhere.

It seemed unfair that Grey got to live and Tyler had to die and everyone just accepted that’s that the way it was—but maybe it didn’t have to be.

That’s why I was here.

The idea that I’d missed something kept niggling at me. I came here after school sometimes and wandered the grounds, trying to find a way down to the basement. In the end, a private tour seemed like the only option to get to where I wanted to go.

I checked the time on my phone. Almost sunset. “Any chance we could see the basement?” I asked our guide.

“Oh, no. Unfortunately the basement isn’t part of the tour. There are protected Saxon ruins beneath the foundations of the mill.”

I sighed. It would be so easy to reach out and rest my finger on her lips and have her do exactly what I wanted her to. “That’s okay. Actually, I really have to pee. Where are the bathrooms?”

“Back the way we came,” she said. “Second right, then your first left. Do you want me to show you the—”

“No, that’s fine. I’ll find my way back. Vivi?”

“Oh,” Vivi said. “Yeah, I’m also suddenly busting for a wee.”

“Okay, I’ll wait here for you both. We still have the Clock Mill and the Miller’s House to get through.”

“Literally cannot wait,” Vivi said.

We turned and started walking. If everything went according to plan, the guide would be waiting for us for a very long time. Days. Weeks, maybe.

“I happen to think tidal mills are very interesting, I’ll have you know,” I said to my sister as we backtracked.

Vivi rolled her eyes. “Of course you would.”

The spiral staircase that led to the basement was easy to find, tucked away behind a door that read STAFF ONLY BEYOND THIS POINT. We headed down into the dark. It was cool and damp here beneath the mill. I turned on my phone flashlight and swept the beam across the space. The walls were brick. The ground was dust. And there, in the center, was a freestanding door. A ruin leftover from Saxon times. A door that used to lead somewhere, but now lead somewhere else.

I texted my mother.

Are you sure you’re okay with this? We could be gone for a while.

Her response dinged into my phone almost immediately, as was her way. Do what you need to do to make things right. You can go anywhere you want—as long as you promise to keep coming back.

We promise.

Okay. I’ll try not to die of worry. I love you.

I love you too. See you . . . soon.

I put my palm against the stone and counted down the seconds until sunset.

On the other side of this door, in another world, I had left a message for a boy carved into a tree: WAIT FOR ME HERE.

I kept thinking back to the moment Grey had tried to put his soul back in his body, to bring him home the same way she had brought us home. How I had seen a shadow of movement at the edge of a clearing and had been certain, for half a heartbeat, that he had been there.

Maybe something of Tyler still remained in that place.

Maybe, if he was there, I could find him.

Maybe, if he was there, I could bring him back.

The seconds ticked over. Somewhere outside, the last of the sun sank below the horizon. The basement smelled suddenly of smoke and decay. The dead began to whisper.

“Ready?” I asked my sister.

“I picked a hell of a day to quit smoking,” she replied.

We held hands. For a moment, a door between this world and the next opened.

We stepped through.