Freiheit in Fesseln: The carpenter Franz Aigner, a kind-hearted but strong and irascible fellow, has beaten a man to death in an argument and is sentenced to prison with a three-year suspended sentence. One of the jurors gets him a job as a bargeman on a Spree barge. There, Franz falls in love with Marie, the bargeman's daughter. But the brutal second bargeman, Paul, also has his eye on Marie and tries everything to provoke Franz into another fight. But it is only when Paul tries to rape Marie that a fight breaks out between Franz and Paul.