With a last glance around, I hurried out on to the 161spiral staircase and looked up at the lantern room. I’d never been brave enough to go up there before, but now I ran quickly up the staircase, right to the top. I was suddenly very glad it was dark because this room had gigantic, triple-height, plate-glass windows. There were a couple of large, circular mirrors lying on the floor, and a huge, three-and-a-half-metre optic dominated the centre of the room, pulsing out a blindingly bright light at intervals. A metal gantry ran round the walls above – I guessed so that keepers and maintenance crew could reach the lantern. But there was no sign of Rosie anywhere.

I made my way back down the tower, checking each room and calling her name as I went. Finally I slipped out through the trapdoor and ran downstairs to where Dad, Kate and Charlie were playing cards at the kitchen table.

“Do you know where Rosie is?” I asked. “I can’t find her.”

“I haven’t seen her,” Dad replied. “Did she go outside for some air?”

I looked out of the window. For a moment, I thought I saw the imprint of white hands pressed 162against the glass, but then I blinked and there was nothing but fog. A wave of dizziness hit me and I clenched my hands together tightly. What the hell was going on?

“It’s really foggy outside,” Kate said. “She shouldn’t be out in this – she might lose sight of the path. Hey, are you OK? You look a bit pale.”

“I’m fine. I’m just worried about Rosie.”

Dad and Kate both got up and said they’d help me look for her.

“Can I come too?” Charlie asked.

“No, wait here,” Kate told him. “We’ll be right back.”

I hurried to the front door, and when I stepped outside the fog was like a blanket that immediately wrapped itself around me, making it hard to breathe.

“Rosie?” I called.

There was nothing but silence. Even the birds and the flies were quiet. I realized I couldn’t even hear the sea. The fog had smothered everything.

“Rosie!” I called again.

“I’m sure she’s just round the corner,” Dad said from beside me. “Why don’t you go back inside, and Kate and I will find her?” 163

I shook Dad off, switched on my phone’s torch and began to walk round the lighthouse. “You two go the other way,” I called over my shoulder. “Then we won’t miss her.”

The weak beam from the torch didn’t help much with the fog, and I couldn’t see any sign of Rosie. When I got about halfway round, I expected to run into Dad and Kate coming from the other direction, but – to my surprise – they never appeared. Soon enough, I was right back where I’d started, beside the front door.

“Rosie!” I called again.