Western Australia 1928. Out on the Tolhurst farmstead Detective Constable Hartley is working on his very first assignment looking into reports of a mysterious prowler. Suddenly he is startled by three gunshots ringing out. Investigating the noise he discovers the corpse of family patriarch Fred O'Donnell shot in the chest - alone in a room that has been locked from the inside. The dead man was almost universally despised which doesn't help Hartley narrow down his pool of potential suspects. But fortunately for him chasing a tenuous clue leads him to meet one very useful man - a nameless mendicant friar with prior experience of solving crimes . . .