Doctor Watson to Hercule Poirot's Sherlock Holmes, Captain Arthur Hastings OBE is an excruciatingly naive and quite stupid English retired military officer. He is an extremely good-hearted and trusting man, which Poirot never tires of making fun of from their earliest encounters throughout the rest of their shared life. Another thing Poirot mercilessly makes fun of Hastings for is the latter's predisposition to fall in love (or at least infatuation) with any auburn-haired girl he encounters.
Hastings marries Dulcie Duveen aka Cinderella at the conclusion of the story Murder on the Links. They emigrate to Argentina to run a ranch although Hastings returns from time to time, such as in the cases Dumb Witness and Curtain.