European produced Western based on the novel by Friedrich Gerstäcker, set in the 19th century in a town on the banks of the Mississippi River. The area is plagued by a gang of pirates under the leadership of Captain Kelly, who live on an island in the river, from where they operate raids on passing steamboats and traders rafts, robbing them of their cargo and murdering the crews. Townspeople and settlers do their best to put an end to the crimes and rid themselves of the pirates and their daring leader.

A mysterious gunfighter named Django is employed by a local crooked political boss as a hangman to execute innocent locals framed by the boss, who wants their land. What the boss doesn't know is that Django isn't hanging the men at all, just making it look like he is, and using the men he saves from the gallows to build up his own "gang" in order to take revenge on the boss, who, with Django's former best friend, caused the death of his wife years before.