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 accepted Lane's strictures about what would be published by them, but by the time of "Poirot Investigates" Christie insisted that their suggested title of "The Grey Cells of Monsieur Poirot" was not to her liking and that the book was to be included in the tally of six books within her contract. The Bodley Head opposed this because the stories had already been printed in "The Sketch". Christie held out and won her case. This was the first Christie book to carry no dedication. The dustjacket front flap of the first edition carried no specially written blurb. Instead it carried