Clint Eastwood plays a quizzical, slightly bemused cowboy in this immensely enjoyable Don Siegel caper, saving nun Shirley MacLaine from a fate worse than death in the Mexican desert. The two leads are perfectly paired, and MacLaine in particular turns in a great comic performance as her ill-fitting habit begins to slip. Siegel keeps the tension and pace roaring along as he pitches his stars into the middle of the Mexican Revolution and all its attendant mayhem, though some may find the final, gory battle scene out of kilter with the light-hearted tone of the rest of the movie.

When a wandering mercenary named Hogan rescues a nun called Sister Sara from the unwanted attentions of a band of rogues on the Mexican plains, he has no idea what he has let himself in for. Their chance encounter results in the blowing up of a train and a French garrison, as well as igniting a spark between them that survives a shocking discovery.