Further adventures of Agatha Christie's Belgian sleuth, Hercule Poirot. The four new cases are entitled: "The Chocolate Box," "The Underdog," "Yellow Iris" and "The Case of the Missing Will.""The Chocolate Box" deals with a Belgian government minister who dies after eating a chocolate from a gift box sent him by a friend. As an up-and-coming policeman, the young Poirot is close to identifying the killer when his superintendent orders him to back off. Now, 20 years later, the detective returns to Belgium to solve the case.
In "The Case of the Missing Will," an educator an Cambridge University, vehemently opposed to women's rights, changes his will, then is found murdered.
"The Underdog" involves a group of British businessmen which hopes to sell the formula to a new chemical compound to the Nazis on the eve of World War II.
In "The Yellow Iris," Poirot visits Buenos Aires, where a group of Englishmen hope to obtain an oil concession from an Argentine general planning a military coup. A woman named Iris, who inherited a large fortune, dies after drinking a toast.