Sir Waffey (Charles Laughton), a famous criminal defense lawyer in London, received treatment for heart disease, but his body was still weak. On the first day of recuperation at home, the nurse strictly supervised him to take medicine and stopped smoking and drinking. In order to facilitate going upstairs, the housekeeper specially built an elevator for him. However, all kinds of care and concern did not work for this unruly and sharp-tongued barrister. Instead, a lawsuit made him excited. Lawyer Mayhew and client Wall (Tyrone Power) visited him and asked him to go out to fight the lawsuit. It turned out that Wall met a rich woman and the two met happily. Although the servants were full of contempt for the egg beater he invented, the rich woman was full of love for him and even modified her will for him, leaving him 80,000 pounds. However, the rich woman was killed. So Wall became the police's number one suspect. His only witness is his wife Christine (Marlene Dietrich), but the latter's indifference and calmness when she came to visit made Sir Waffey suspect that there was something else going on. Behind the confusing case, there are many interlocking and unspeakable secrets... This film is adapted from Agatha Christie's novel of the same name.