Young Jean Berlot’s mother has died in the lunatic asylum at Charenton. On his way home from the funeral he spends a night at a roadside inn. There he has a vivid dream ‚ the same dream he always has in times of stress, in which two hospital orderlies in white coats try to force him into a straitjacket. After a violent struggle, Berlot always wakes up to find that the room has been completely demolished. Another guest at the inn, the Marquis, witnesses the nightmare and its results. He pays for the damage and invites Berlot to his castle. On the way he hears Berlot’s story: when his father died his mother, who was much younger, went mad with grief. Since then Jean, who takes after her, has been haunted by the idea that he too will end up in an asylum ‚ hence the nightmares. But the staying at the Marquis’ castle will be therapeutic. After witnessing a blasphemous orgy and an unorthodox funeral, the Marquis helps him conquer his fears and takes his guest to an asylum where the patients have complete freedom and the staff are locked up behind bars.