The Big Four (Hercule Poirot #5)

Agatha Christie's beloved detective Hercule Poirot takes on an international gang of super-criminals and introduces the world to his identical twin, Achille Poirot.

When a series of apparently unconnected murders attracts the attention of Hercule Poirot, one small detail stands out: the mysterious recurrence of the number four. Poirot travels from London to Paris and from Belgium to Italy, solving one mystery after another but always remaining a step behind the shadowy foursome he suspects are responsible. A final daring confrontation puts the eccentric detective's life on the line--until his twin brother, Achille Poirot, comes to the rescue.