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Murder on the Orient Express

Agatha Christie

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Murder on the Orient Express | Part 3, Chapter 7 : Poirot Sits Back and Thinks (The Identity of Mary Debenham) | Summary



When Mary Debenham arrives in the dining car, she makes eye contact with Colonel Arbuthnot before speaking to Hercule Poirot. He asks why she lied earlier that day, and she readily admits she lived in America and worked for Daisy Armstrong's family. She explains she lied to avoid publicity, as she feared media reports she had been detained in relation to a murder would hinder her ability to find decent governess posts. Poirot says he would have been the better judge of that and points out she could have identified Countess Andrenyi as Sonia Armstrong's younger sister. Debenham denies recognizing her, even though she had thought she looked familiar.

Despite Poirot's gentle coaxing, Debenham steadfastly refuses to reveal her secret and explain the conversation Poirot overheard. She bursts out crying, and Colonel Arbuthnot threatens Poirot. After Debenham regains her composure, she rushes out of the dining car. Arbuthnot proclaims her innocence and says if Poirot interferes with Debenham again, he'll "have [Arbuthnot] to deal with."

M. Bouc and Dr. Constantine compliment Poirot on "another miraculous guess." Poirot confesses it was not a guess, but information revealed by the countess. She had described her governess as a tall, middle-aged, red-haired woman named Miss Freebody. When Poirot asked for her name, the countess invented one on the spot, using a name from a store in London, Debenham and Freebody. Bouc asks if everybody on the train tells lies, and Poirot responds, "That is what we are going to find out."


Mary Debenham knows the jig is up the minute she exchanges a look with Colonel Arbuthnot. So Hercule Poirot's ploy does work, and she immediately admits her lie. She gives a skillful explanation, but it sounds staged. So does her claim that she didn't recognize Countess Andrenyi.

Colonel Arbuthnot's threats are out of character for a man who claims to have just met a woman three days earlier. Thus there is another lie to be uncovered to identify their true relationship. Poirot is amused by his outburst because his emotions confirm their relationship is much deeper than they are letting on.

Once again Poirot uses a seemingly minor fact to ferret out the truth. When he asks the countess the name of the governess, he most likely doesn't expect her to tell the truth. Yet he persists because the answer could be valuable. It is. The countess reacts to the surprise question by making a word association with something she is familiar with and thus gives away more than she intends to.

While Poirot is finally making headway in identifying the false information, he still has not learned Debenham's secret. Her refusal to divulge it suggests it may indicate a bigger motive for murder than being the Armstrongs' governess.

Bouc's and Poirot's comments at the end of the chapter seem like mere chatter. They are not insignificant observations, however, in the hands of Christie. After reading the entire novel, one can review these comments—and many similar ones—in hindsight and see Christie giving notice of what is to come. Bouc wonders if everyone on the train is lying and Poirot says they are going to find out. How would it change things if everyone were lying? What would motivate the passengers and conductors to lie? And

because Poirot has stipulated he could identify the murderer through a process of elimination, how can he eliminate suspects if everyone is lying?

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