The second in a quartet of exquisitely haunting ghost stories set in the wilds of Scotland.

The Isle of Stroma, 1896. Tom Torrance has been sent to oversee the completion of a new lighthouse, which will guide ships through one of the most dangerous stretches of water in the United Kingdom. The construction so far has been plagued by difficulties, giving rise to superstitious whisperings amongst the men, but Tom is a man of sense and science. He will not be cowed by stories of hauntings and bad omens.

Yet Tom is unprepared for the conditions on the island: the isolation and delirium of the endless summer nights. He soon learns that the real dangers on the island have nothing to do with the wild waves. There are some problems that science cannot answer, and some threats so ancient and strange, that nothing can keep them at bay.