For Christmas, aging millionaire Simeon Lee decided to gather his entire extended family for a last-minute celebration. But the festivities were unexpectedly interrupted by a furniture crash, followed by a terrifying scream. The family, who had rushed to the scene, discovered the head of the family lying in a pool of blood in the middle of his study. Inspector Sugden, who, by a lucky coincidence, was staying with the incomparable detective Hercule Poirot, was called to the crime scene. Naturally, he also arrived at Lee's house, where he discovered an atmosphere of general suspicion. The millionaire could have been murdered by anyone, for the entire family secretly hated this family tyrant. There were numerous clues, but none of them pointed to any of those present. Here was a real case for the great Belgian's 'little gray cells'...