Sparkling Cyanide is a work of detective fiction by British writer Agatha Christie, first published in the US by Dodd, Mead and Company in February 1945 under the title of Remembered Death and in UK by the Collins Crime Club in the December of the same year under Christie's original title. The US edition retailed at $2.00 and the UK edition at eight shillings and sixpence (8/6).
The novel features the recurring character of Colonel Race for his last appearance to solve the mysterious deaths of a married couple, exactly one year apart. The plot of this novel expands the plot of a short story, "Yellow Iris".
Plot summary
One year earlier, seven people sat down to dinner at the Luxembourg restaurant. One, Rosemary Barton, never got up; instead she collapsed and died. The coroner ruled her death suicide by poisoning, due to post-flu depression. However, each of the guests had reason to want her dead: Iris, Rosemary's sister, had recently learned that she was the sole beneficiary of her sister's will. George, Rosemary's husband, had discovered her love letter to another man and her plans to leave her marriage. Anthony Browne was a friend of Rosemary who she had accidentally discovered had served time in prison. He was also briefly infatuated with her before becoming attracted to Iris. Stephen Farraday had had an affair with Rosemary, but later grew to resent her attachment to him and feared she would destroy his career and his marriage. Sandra, Stephen's wife, had learned of the affair and worried her husband would leave her for Rosemary. Ruth Lessing, George's secretary, would have been free to marry him with his wife out of the way. She secretly hated Rosemary.
After Rosemary's death, her aunt Lucilla Drake moves in with George and Iris. She shows blind loyalty to her son, Victor, who is constantly requesting money from the family. Anthony returns to town from travel and forms a friendship with Iris. Six months later, George receives anonymous letters saying that Rosemary was murdered. George investigates and decides to repeat the dinner at the same restaurant, with the same guests, plus an actress who looks like his late wife, and who is meant to arrive late and startle the murderer into making a confession. A few days after the one-year anniversary of Rosemary's death, the dinner is held, ostensibly to celebrate Iris's eighteenth birthday. The actress does not arrive and George dies at the table – poisoned, like his wife, by cyanide in his champagne. His death might have been judged as suicide, but George shared his concerns and some of his plan with his friend Colonel Race.
Stephen is interrogated by the police, who suspect him of the two murders. However, Colonel Race suspects that Anthony killed Rosemary to silence her and is now pursuing Iris for her wealth, inherited from Rosemary. However, upon meeting him he realizes Anthony is not a criminal at all, but is really a government agent. Iris confesses to Anthony that after George's death, she discovered cyanide in her purse, making it appear that the murderer was attempting to frame her.
After more investigating, Race incorrectly presumes the murderer to be Iris, but Anthony (after a trick with Race’s, Anthony’s and Chief Inspector Kemp’s drinks) has figured it all out.
Anthony realizes that Iris was the intended victim, not George, and Ruth was conspiring with Victor Drake (who she hoped to marry) to ensure he would inherit the family money. After the entertainment, George proposed a toast to Iris, when all sip champagne except her. When the group left the table to dance, Iris dropped her bag; a young waiter, retrieving it, misplaces it at the seat adjacent to hers. When, in the dark, the group returned to the table, Iris sat next to her original seat because of the misplaced bag. Everyone else therefore sat one seat away from where they were. George sat at Iris's original seat and drank the poisoned champagne. The anonymous letters to George were sent by Ruth, who then encouraged him to re-stage the dinner at the Luxembourg so that Victor and Ruth could kill Iris, as they killed Rosemary. To support a decision of suicide, Ruth had planted a packet of cyanide in Iris's bag, which packet dropped to the floor when she pulled her handkerchief out, without touching it (no fingerprints on it). Victor acted as a waiter, to drop the poison in the champagne during the show.