A tramp is found murdered in the woods near Marshwood. Superintendent Ron Pringle (who is on the point of retirement) has a local poacher arrested and charged, and he is later convicted of the crime. But then there is a second murder, and Barnaby thinks Pringle has got it badly wrong. He intends to see matters straightened out. Then Pringle himself is killed in what seems at first to be a riding accident - but Barnaby rightly suspects foul play.