Hastings, while being no great detective himself, serves Poirot in many ways. A former British Army officer in World War I, he is brave. He has courage and is often used by Poirot for physical duties such as catching and subduing a criminal. Poirot likes to tease Hastings about being dim-witted at times, but he clearly enjoys the Captain's company. In "The Mysterious Affair at Styles" and "The A.B.C. Murders", Hastings plays a prominent role in the resolution of the mystery, with a casual observation that leads Poirot to the guilty party: In case of the former, by mentioning that Poirot had to straighten some spill holders and ornaments in Styles, he prompts Poirot to realise that someone had moved them, causing Poirot to discover a crucial piece of evidence. In the case of the latter, he suggests that the error in recipient address of a letter by the murderer was deliberate, thus causing Poirot to realise the murderer had attached greater importance to that particular murder.