In an isolated hut not far from the sleepy country town of Merino, stockman George Kendall is found dead and it looks very much like murder. Six weeks later, when the murderer is still at large, another stockman turns up in the township and, as a first move, provokes the local sergeant to lock him up. This particular stockman is Detective-Inspector Napolean Bonaparte, and there's method in his seeming madness. While serving a semi-detention sentence and being made to paint the police station, he wears the best of all possible disguises for a policeman on the trail of a ruthless and single-minded killer.