It is 1919, the Great War is over and Inspector Ian Rutledge returns to Scotland Yard to resume his career. But he is burdened with a secret: he is suffering from shell shock and constantly hears in his head the taunting voice of Hamish MacLeod, who was killed on the battlefield.
In a desperate gamble to salvage his sanity, Rutledge takes on his first assignment. But the case spells disaster no matter what the outcome. In a Warwickshire village, Colonel Harris, a respected army officer, has been shot dead, and the chief suspect is Captain Wilton, an equally popular and much-decorated war hero. As Rutledge digs into the lives of the villagers he realises that his reputation at the Yard and his last hope of avoiding the dark abyss that his only witness inhabits depend upon solving this case.