Madeleine, a young nurse, makes a fatal mistake that costs the life of the patient Léopold Sicard. She leaves the hospital after her colleague, Dr. Senez, writes a damning report against her. Some time later, the young psychologist Paul Forest receives at the end of one of his lectures a visit from his childhood friend, Roger, who tells him of his fears about the strange behavior of his wife, who is none other than Madeleine.