On Leck Island off the Atlantic coast of Ireland, Caitriona’s only worry is how she and her friends will spend the long school summer holidays ahead of her — and how to make an impression on the handsome Seamas, of course. After human remains are discovered by archaeologists at the coast guard station, a spooky night visit to the station causes them to remember a story about a man who disappeared without trace from the island one hundred years previously. It is all good fun, until something awful happens that puts the lives of Caitriona and her friends in dissarray.