Hercule Poirot met his lifelong friend, Captain Arthur Hastings, and solved the first of his cases to be published, "The Mysterious Affair at Styles". It is clear that Hastings and Poirot are already friends when they meet in Chapter 2 of the novel, as Hastings tells Cynthia that he has not seen him for "some years". Particulars such as the date of 1916 for the case and that Hastings had met Poirot in Belgium, are given in "Curtain: Poirot's Last Case", Chapter 1. After that case, Poirot apparently came to the attention of the British secret service and undertook cases for the
Poirot Investigates clue. According to Poirot, Miss Marsh proved her superior intelligence by employing Poirot to solve the case. The American edition of the book, published one year later, featured an additional three stories which did not appear in book form in the UK until 1974 with the publication of "Poirot's Early Cases". The review in "The Times Literary Supplement" of 3 April 1924 began with a note of caution but then became more positive: "When in the first of M. Poirot's adventures, we find a famous diamond that has been the eye of a god and a cryptic message that it