On the Scottish Hebridean Island of Islay, five corpses are dug up by a peat-cutter. All of them have been shot in the back of the head, execution style.
Sent across from the mainland to investigate, Inspector Angus Blue and his team slowly piece together the little evidence they have, and discover the men were killed on a wartime base, over 70 years ago.
But there are still secrets worth protecting, and even killing for. Who can Inspector Blue trust?