From the lighthouse logbook

Found in a lighthouse logbook. The keeper's entries have been copied as written.

3 Nov. Wind north-west, moderate. Visibility good. Lamp lit 16:40. A light seen at sea, about eight miles south. No ship expected. Logged and reported.

4 Nov. Wind dropping. The same light again at dusk. Closer, perhaps six miles. It does not move like a ship. It does not drift. It comes straight toward the rock and then stops.

5 Nov. Calm. The light at four miles. The radio says there is nothing out there. I have looked through the glass for an hour. It is a lamp, like ours, but the colour is wrong. Greener. I do not like it.

6 Nov. The light at two miles. It came up at the moment I lit our lamp, as if answering it. I tried keeping ours dark for ten minutes. It went dark too. When I lit ours again, it lit again. It is copying me.

7 Nov. One mile. In the glass I can see that it stands on something, tall and thin, rising out of the water where no rock is marked on any chart. I can see a gallery. I can see a figure on the gallery. It is looking at me through its own glass.

8 Nov. I waved. It waved. I stopped. It did not.

9 Nov. No light tonight. The sea is empty. I slept for the first time in five days.

10 Nov. Woke at 03:00. Our lamp was turning, though I had not lit it. The light was green. There are wet footprints on the stairs, coming up from the door, and the door is still bolted from the inside.

11 Nov. I looked through the glass toward the south. Eight miles out, there is a light. It is the right colour. Yellow, steady, warm. A proper lamp. I know that lamp. I have tended it for nineteen years.

There is someone on its gallery, waving.

There are no entries after 11 November. The relief keeper found the lighthouse empty and the logbook open on the table. The lamp was green.