M. Bouc

Monsieur Bouc is Hercule Poirot's friend and fellow Belgian in Murder on the Orient Express, a director of the train operator Compagnie Internationale des Wagons-Lits. When the train is fully booked, he gets Poirot a berth, later gives him his own first-class space, and after the murder tells Poirot that Ratchett is dead and the killer is still aboard. He reviews the case with Poirot and Dr Constantine, and at the end the two of them decide that Poirot's first, simpler solution should be the one given to the police.