Ian Carew is a mild-mannered teacher at the primary school in Mirebury, a quiet town lost in the moors. Six years after leaving London, he's still considered a newcomer, but his elderly neighbour, Mary Hopkins, treats him like a son, and the local butcher, Jack Fuller, is his best friend. All that's missing from Ian’s life is a touch of romance and a dash of adventure. Little does he know, he's about to get a taste of both. When Mary Hopkins opens her letterbox and makes a gruesome discovery, Mirebury is thrown into a state of shock and outrage. At first, the townsfolk assume it was a random act, but the horrible deliveries continue and they're forced to acknowledge they have become the target of a campaign of terror - and nobody’s letterbox is safe.

Is the Postman one of them, or an outsider? Tensions grow as suspicion and accusations tear the town apart. Neighbour is pitted against neighbour and tempers flare. The Postman only strikes at night and moves through the fog like a ghost. Catching him seems impossible, but Mirebury fights back, and in the end, the fate of the town will come down to one man.