When private detective Agatha Raisin comes across a severed leg in a roadside hedge, it looks like she is about to become involved in a particularly gruesome murder. Looks, however, can be deceiving, as Agatha discovers when she is employed to investigate a case of industrial espionage at a factory where nothing is quite what it seems. The factory mystery soon turns to murder and a bad-tempered donkey turns Agatha into a national celebrity, before bringing her ridicule and shame.