The mutiny of the prisoners against the unhuman methods used by the director of prison.
Lots of men are squashed in the cell of an American prison. The bald Billy cannot sleep; he is horrified to death at the thought of the things to come. He silently wakes up a friend who recollects how little it takes the sadistic prison director to take a prisoner outside the building and kill him. Billy has already won his disfavour when he interrupted his yelling at the line up by playing harmonica. The worries are justified. The director makes him muster and Billy disappears for ever. His friend lets his co-prisoners know about it after the reveille by playing Billy’s melody on an imaginary harmonica. Some of them join him after a while by imitating other musical instruments. The smooth director shaves and is captivated at the sight of a bloodstain from his slightly cut face on his hand. The strain of the prisoners culminates in their demolishing the modest furnishings. The guards call for the director who crushes the rebellion. Only Billy’s friend keeps playing the “harmonica”, the others do not dare any more. It is clear now who is going to be the next target of the director’s cruel revenge.