What is the subtitle of the Agatha Christie novel "Curtain"?

"Curtain: Poirot's Last Case" is a work of detective fiction by British writer Agatha Christie, first published in the UK by the Collins Crime Club in September 1975 and in the US by Dodd, Mead and Company later in the same year. It is the last novel published by Christie before her death. "Sleeping Murder", published posthumously, is her final novel.

The novel features Hercule Poirot and Arthur Hastings in their final appearances in Christie's works. It is a country house novel, with all the characters and the murder set in one house. Not only does the novel return the characters to the setting of her first, The Mysterious Affair at Styles, but it reunites Poirot and Hastings, who last appeared together in Dumb Witness in 1937. The fictional detective dies at the end. It was adapted for television in 2013.

Dame Agatha Mary Clarissa Christie, Lady Mallowan (née Miller; 15 September 1890 – 12 January 1976) was an English writer known for her 66 detective novels and 14 short story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. She also wrote the world's longest-running play, the murder mystery The Mousetrap, which has been performed in the West End since 1952. A writer during the "Golden Age of Detective Fiction", Christie has been called the "Queen of Crime".