In order to get rid of his troublesome son François, Maître Gérane manages to have him committed to a mental hospital owned by Dr. Varmont, a supporter of traditional treatments, in constant conflict with Dr. Emery, whose therapy takes the psychology of patients into account. François soon makes friends with Heurtevent, a sweet epileptic, and both decide to escape from the place. Their attempt is a failure and Heurtevent, unable to get over what he considers a return to hell, commits suicide. But rebellious François tries again and this time around he is successful. He finds shelter at his friend Stephanie's home...