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
Parker Pyne Investigates comprises twelve of her fourteen stories featuring detective James Parker Pyne; the two remaining stories, "Problem at Pollensa Bay" and "The Regatta Mystery" were later collected in "The Regatta Mystery" in 1939 in the US and in "Problem at Pollensa Bay" in the UK in 1991 although these were originally stories featuring Hercule Poirot when they were first published in the "Strand Magazine" in 1935 and 1936 respectively. The book also features the first appearance of the characters of Ariadne Oliver, and Miss Felicity Lemon, both of whom would go on to have working relationships with Hercule Poirot in later