Count Armand de la Rochefour

Not to be confused with Armand, the Comte de la Roche (The Mystery of the Blue Train)

Count Armand de la Rochefour is a suitor of Flossie Carrington, the daughter of the wealthy American steel tycoon Ebenezer Halliday. Poirot described Rochefour as "Un bien mauvais sujet". He was an adventurer pure and simple, who knew how to appeal to a romantic young girl. Some years before the events in the story, he had met Flossie in Paris and attempted to win her favour. Halliday noted this and took Flossie back to America in a hurry.

However, shortly before Flossie died, she had received a letter from the count which suggested that they were rekindling their affair. Halliday suspected Rochefour of killing his daughter more than he suspected her estranged husband Rupert Carrington. Nonetheless, Poirot did not consider Rochefour a plausible suspect. It was clear that he was only interested in money. Therefore why did he bother to kill Flossie? Why not simply take the jewels? Poirot knew that Flossie would never denounce him. She had once loved him. She would rather suffer her loss in silence. The count, whom Poirot believed understood the psychology of women just as well, knew this also.

Portrayals
Count Armand de la Rochefour was played by Alfredo Michelson in the film adaptation of The Plymouth Express in Series 3 of ITV's Agatha Christie's Poirot. While the count did not have a speaking part in the original story, his role is considerably enlarged here. He is seen arriving in London at the beginning of the episode. Halliday actually engages Poirot to try to keep him away from Flossie. Poirot undertakes this task reluctantly and he and Hastings observe the Count and Flossie at a meal in a restaurant. The Count is also involved in some other shady dealings. He started a rumour in Paris that a survey on one of Halliday's mining concessions would shortly issue a negative report. This caused the price of Halliday's mining stock to fall drastically. Rochefour then bought a large quantity of the shares with instructions to sell them again when the price went up (which it would once the rumour was found to be untrue). Japp arrested Rochefour when he was trying to board a train to depart England. He was carrying a large quantity of bearer bonds. Rochefour claimed that he had done nothing wrong and his share transaction was a routine piece of speculative investment. However Japp told him this was something the financial regulators would decide.

In NHK's anime adaptation The Plymouth Express, the Count is seen only in a number of flashbacks and he does not have any lines.