Sparkling Cyanide
Agatha Christie
 One year ago on 2 November, seven people sat down to dinner at the restaurant "Luxembourg". One of them, Rosemary Barton, never got up. She was thought to have committed suicide due to post-flu depression. Her husband, George Barton, received anonymous letters saying that Rosemary did not kill herself but was murdered. George started to investigate and decided to reconstruct the dinner at the same restaurant, inviting the same people as well as an actress that looked like his late wife. The actress did not arrive and that night George died at the table - poisoned, like his wife, by cyanide in his glass. His death would have been dismissed as suicide as well if not for the investigation of his friend Colonel Race. During the investigation it is revealed that the intended victim was Rosemary's young sister Iris. Due to a stipulation of her uncle's will as Rosemary died childless her inherited fortune passed to her teenage sister when she died. If Iris had died at the table as intended the money in turn would have passed to her aunt Mrs. Drake. Mrs. Drake is very much at the mercy of her lazy son Victor, who often threatens to commit suicide when he needs money from his mother. Colonel Race and Iris's suitor, Anthony Browne, discover that Victor had planned the murder together with his lover Ruth Lessing, who was also George's secretary. The plan failed because when the group went to dance Iris dropped her bag and the waiter that retrieved it placed it a seat away from where she was before she went to dance. When the companions returned to the table, George sat at Iris's original place and drank the poisoned champagne. In order to confirm the suicidal nature of the death Ruth had planted a pack of cyanide in Iris's bag and Victor had disguised himself as a waiter in order to poison the sparkling wine. When this failed, Ruth then attempted to run down Iris with a car. Eventually, Colonel Race together with the police and Anthony Browne unravel the truth and save Iris from being gassed to death by Ruth, who had knocked her out, trying to stage her "suicide'. The anonymous letters to George were sent by Ruth in order to convince him to re-stage the dinner at Luxembourg so that Victor and Ruth could try to kill Iris.