Hercule Poirot sort of obsessive-compulsive" in Poirot. As mentioned in "Curtain" and "The Clocks", he is fond of classical music, particularly Mozart and Bach. In "The Mysterious Affair at Styles", Poirot operates as a fairly conventional, clue-based and logical detective; reflected in his vocabulary by two common phrases: his use of "the little grey cells" and "order and method". Hastings is irritated by the fact that Poirot sometimes conceals important details of his plans, as in "The Big Four". In this novel, Hastings is kept in the dark throughout the climax. This aspect of Poirot is less evident in the later novels,
Hercule Poirot allowed the murderer to escape justice through suicide and then withheld the truth to spare the feelings of the murderer's relatives. In "The Augean Stables", he helped the government to cover up vast corruption. In "Murder on the Orient Express", Poirot allowed the murderers to go free after discovering that twelve different people participated in the murder. The victim had been responsible for a disgusting crime which had led to the deaths of no fewer than five people. There was no question of his guilt, but he had been acquitted in America in a miscarriage of justice. Considering it poetic