Mr. Shaitana, a wealthy collector of objets d'art, has an unusual idea for a dinner party after a chance meeting with Hercule Poirot in an art gallery. He invites to dinner four detectives plus four people he suspects may have gotten away with murder.
Along with Poirot are two detectives we have met in earlier Christie works: Colonel Race, the trouble-shooter from the Foreign Office, and Superintendent Battle of Scotland Yard. Introduced in this book is Mrs. Ariadne Oliver, a best-selling mystery writer, who has been compared to Christie herself. Like Mrs. Christie, Mrs. Oliver eats large quantities of apples while writing and Mrs. Oliver's books are about a quirky Finn who is not unlike Mrs. Christie's quirky Belgian. Mrs. Oliver will return in six additional novels.
The other four guests that evening are: Dr. Roberts, a successful physician; Mrs. Lorrimer, an affluent widow who loves to play bridge; Major Despard, an African and South American explorer and guide; and Miss Anne Meredith, a young lady Shaitana met in Switzerland.
After dinner, a game of bridge is arranged. Shaitana directs the four detectives to one room while the other four guests play in a separate room. The host says he does not like the game so sits and dozes by the fire in the room where the four possible murderers are playing. When the guests prepare to leave later, it is discovered that Shaitana has been fatally stabbed at some point in the evening.
All four detectives tackle this case in their own way. Bridge players will delight in the way Poirot handles the case. He concentrates on the game itself, the hands that were dealt, and the method of scoring. If you pay attention to the game, you just might guess the murderer.
This is one of Christie's classic surprise endings and, in my opinion, one of her best works.