I pushed harder at the door, throwing all my weight against it, and this time it opened. Only it wasn’t Rosie in the Strangers’ Room. There were birds. Dozens and dozens of them forming a white carpet across the floor. The window was open, and I guessed they’d got into the room by mistake, but rather than flapping about in a panic, squawking 192and shrieking, they were standing completely silent and motionless, all looking up into the curved mirror. I could see their beady little eyes watching me from the warped old glass.

My mind flew back to the last letter I’d found on the back of Charlie’s drawing.

It’s not an illness like we first thought

– it’s the lighthouse…

The birds that get inside the building go mad… It was like they’d been staring into the mirror for so long that they’d forgotten they were birds at all…

How was the window even open? I was sure I’d closed it when I’d been up here earlier. There must have been fifty birds in the room. After the disturbing things I’d read about them in those old letters, I felt nervous about getting too close, but they couldn’t stay in the lighthouse. So I came into the room, shut the door behind me so they couldn’t get to the stairwell, and then began shouting and waving my arms at them.

This seemed to shock them back to themselves, and suddenly they were behaving like ordinary birds 193again, flapping about, screeching, looking for the exit. It was a large window, and to my relief it wasn’t too difficult to usher them back outside. Soon the room was empty again, the only sign of the birds the occasional stray feather, some smears of guano on the floor, and of course their dreadful stink.

I closed the window firmly and then went back down to the room with the photos. They were all still scattered about on the floor where I’d left them, and the writing on the walls seemed to scream out a warning at me – a warning that I had heeded too late.

Could this have happened before? To one of the lighthouse keepers? Perhaps that was why some of them had been thought mad. Perhaps they alone had remembered a person that everyone else had forgotten. Later that afternoon, I was going to track down Will and make him tell me everything he knew about the lighthouse and what exactly had happened to his sister, but for now I had the logbooks to read. 194Surely something in there might help me work out how to get Rosie back.

I quickly realized, though, that it was a daunting task. There had been dozens of lighthouse keepers at Bird Rock over the years – even more than you might expect because so many had requested transfers and ended their terms early.