I’d had more than enough of this weird place, so I slipped back down the spiral staircase and hurried to close the trapdoor. I didn’t move quite fast enough, though. There were footsteps behind me and I turned to see Rosie emerging from our bedroom doorway.

“What’s this?” she said, staring. “Did you find a way into the tower? I thought it was chained up.”

I gestured at her to be quiet and then ushered her back into our bedroom. “Don’t tell anyone,” I said. “Will was here last night. He wanted to read the logbooks upstairs, so he cut the chain. Dad will be furious if he finds out.”

I was worried that Rosie might ask why Will was so interested in the lighthouse. I certainly wasn’t going to tell her the truth. Much as she loved ghost stories, she preferred them to be very old – like a missing keeper who’d disappeared a hundred years ago or a Victorian lady spotted beside a crumbling gravestone. Ever since her illness, she’d been especially sensitive to any real-life stories involving teenage girls dying before their time. Hearing about things like that could send her into a dark place for days 121and weeks on end sometimes. Fortunately she was too interested in the lighthouse itself to ask about Will’s reasons for being there.

“And you weren’t going to tell me?” she said, incredulous. “There must be the most amazing photo opportunities up there!”

She grabbed her camera from our room and then headed over to the spiral staircase. I knew it was useless trying to stop her – I’d seen that look on her face too many times before. She went straight up the stairs to the trapdoor, ignoring my hissed instruction to wait, and disappeared through it. My instinct was to follow, but I was worried that Dad might come looking for us, so I made myself hurry back downstairs to tell him that Rosie and I wanted some fresh air and were going for a walk. Luckily Dad and Kate were still preoccupied with how difficult Charlie was being, so they barely looked up to acknowledge what I’d said.

I left them to it and hurried back to the trapdoor, pulling it into place behind me before chasing after my sister. I hoped she might have started with the bottom rooms and that I’d find her fairly quickly, but there was no sign of her and I guessed she’d headed 122straight for the top of the tower. I gritted my teeth as I followed. With every step on the tightly wound spiral stairs, my knees became shakier and I could feel my palms growing sweaty as my vertigo kicked in.