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
Hercule Poirot years "later" than it was published, and so must any of the cases that refer to it. One alternative would be that having failed to grow marrows once, Poirot is determined to have another go, but this is specifically denied by Poirot himself. Also, in "The Erymanthian Boar", a character is said to have been turned out of Austria by the Nazis, implying that the events of "The Labours of Hercules" took place after 1937. Another alternative would be to suggest that the Preface to the "Labours" takes place at one date but that the labours are completed over a