Poirot Investigates is a 1924 short story collection by the famed English mystery novelist Agatha Christie. The collection contains eleven stories all starring Christie's most famous creation, the detective Hercule Poirot.
"The Adventure of the Western Star" concerns an American film star named Miss Mary Marvell who receives a threatening letter demanding that she return her most prized diamond jewel to the eye of an idol where it was found. "The Tragedy at Marsdon Manor" is about an insurance agent who asks Poirot to investigate a man who dies of an internal hemorrhage just weeks after signing up for a hefty life insurance policy. "The Adventure of the Cheap Flat" concerns a rather trivial matter that escalates into a tale of murder and intrigue. Poirot becomes interested in the mystery of how some colleagues of his were able to obtain a much desired flat in a fancy part of town so cheaply.
"The Mystery of Hunter's Lodge" follows the son of a baronet and husband to a film actress who receives word that his uncle has been murdered. "The Million Dollar Bond Robbery" is about the theft of a million dollars worth of bonds and the efforts of Poirot to prove that his associate Philip Ridgeway is innocent of the crime. The real culprit is revealed to be Mr. Shaw, one of two managers of the bank entrusted with the bonds. "The Adventure of the Egyptian Tomb" describes the death of a famous Egyptologist of heart failure and the death of the Egyptologist's financier of blood poison. The deaths are suspicious for having taken place just a fortnight apart.
"The Jewel Robbery at the Grand Metropolitan" concerns the theft of expensive jewelry belonging to Mr. and Mrs. Opalsen while they are staying at the same fancy hotel as Poirot and his associate Hastings. "The Kidnapped Prime Minister" describes the attempted assassination and eventual kidnapping of the British Prime Minister while on his way to Versailles for a secret meeting that would end World War I. "The Disappearance of Mr. Davenheim" is about a bet Poirot makes that he can solve the mystery of the titular banker's disappearance within a week without even moving from his chair.
"The Adventure of the Italian Nobleman" is about the death of Count Foscatini whose head has been smashed by a marble statue. "The Case of the Missing Will" concerns a strange post-mortem ultimatum made of Miss Violet Marsh by her recently departed uncle that she must live in his old country manor for a month and "prove her wits" to receive her inheritance; otherwise the entire inheritance will be given to charity and she will be left with nothing.