Hercule Poirot's quiet supper in a London coffeehouse is interrupted when a young woman confides to him that she is about to be murdered. She is terrified - but begs Poirot not to find and punish her killer. Once she is dead, she insists, justice will have been done. Later that night, Poirot learns that three guests at a fashionable London Hotel have been murdered, and a cufflink has been placed in each one’s mouth. Could there be a connection with the frightened woman?

It’s December 19, 1931. Hercule Poirot and Inspector Edward Catchpool are looking forward to a much-needed, restful Christmas holiday, when they are called upon to investigate the murder of a man in a Norfolk hospital ward. Cynthia Catchpool, Edward’s mother, insists that Poirot stay with her in a crumbling mansion by the coast, so that they can all be together for the festive period while he solves the case.

Mr. Shaitana is famous as a flamboyant party host. Nevertheless, he is a man of whom everybody is a little afraid. So when he boasts to Hercule Poirot that he considers murder an art form, the detective has some reservations about accepting a party invitation to view Shaitana's "private collection". Indeed, what begins as an absorbing evening of bridge is to turn into a more dangerous game altogether.

Mrs. Packington felt alone, helpless, and utterly forlorn. But her life changed when she stumbled upon an advertisement in the Times that read: "Are you happy? If not, consult Mr. Parker Pyne." Equally adept at putting together the fragments of a murder mystery or the pieces of a broken marriage, Mr. Parker Pyne is possibly the world's most unconventional private investigator. Armed with just his intuitive knowledge of human nature, he is an Englishman abroad, traveling the globe to solve and undo crime and misdemeanor.

This mystery novel follows Anthony Cade, a man who unknowingly finds himself in the middle of an international conspiracy and a murder investigation after accepting a simple delivery job from an old friend. As Cade slowly begins to realize his predicament has potentially put him in danger, he begins his own investigation into the strange series of events just as Inspector Battle of Scotland Yard begins the main, official investigation.