This French thriller begins at a small boarding school for boys. The principal is a difficult man who is married to a wealthy but frail teacher, and his mistress is another one of the teachers. Because he has been awful and abusive to both of the they befriend each other and devise a plan to kill him. They lure him away from school and eventually drown him in a bathtub. They go back to the school and dispose of the body in the murky pool. The deed is done and they are both apprehensive, especially the frail wife. When the pool is finally drained there is no body! This and other strange occurrences further frighten the wife and she becomes sickly. However, she could never expect what she saw one night that led her to die of fright. The twist at the end of the film is good. It is rumored that Hitchcock tried to get the rights to this story. He would just have to settle for making Psycho instead. What a shame.