The German Keller family pays a visit to their Croatian friends who live in a small village on the banks of the Cetina river. Inspired by the stories told to them by their fathers about the history of the area being used as the filming ground for the cinematic adaptations of German author Karl May's seminal Winnetou series of western novels, the children decide to play Cowboys and Indians. However, what they don't know is that the canyon they've picked as their play area, serves as the hiding spot of three ruthless Serbian chetniks, who had recently escaped from the nearby prison.