In Murder on the Orient Express by Agatha Christie, M. Bouc is an executive at the railway company that operates the Orient Express train. He is also an old friend of Hercule Poirot. When the book opens, we see M. Bouc give up his compartment to Poirot, which places Poirot in the same car where a murder will be committed.

After the murder occurs, M. Bouc asks Poirot for his help. He tells Poirot “And now a passenger lies dead in his berth—stabbed.” M. Bouc spoke with a kind of calm desperation.” Fortunately, Poirot agrees to investigate. In chapter 8, Poirot updates M. Bouc on the case. He tells M. Bouc:

“I have discovered the identity of the victim. I know why it was imperative he should leave America… Do you remember reading of the Armstrong baby? This is the man who murdered little Daisy Armstrong. Cassetti.”

“I recall it now. A shocking affair—though I cannot remember the details.”

Bouc clearly regards the story of Daisy Armstrong with shock and disgust as well as sadness for little Daisy’s family and friends. Poirot relates the story in its entirety. Daisy’s father, Colonel Armstrong, was an Englishman who lived in America with his wife—the daughter of a famous actress—and their daughter Daisy “whom they idolized.”

When Daisy was three years old, she was kidnapped and ultimately found murdered. This tragedy resulted in the death of the entire Armstrong family, as Mrs. Armstrong “gave birth prematurely to a dead child, and herself died. Her broken-hearted husband shot himself.” In addition, a nursemaid who was falsely accused committed suicide. She was subsequently found “absolutely innocent of any complicity in the crime.”

Upon hearing these details, Bouc says, “Mon Dieu, what a tragedy. I remember now.” Then, upon learning that the man who was murdered on the train, Cassetti, is the kidnapper and murderer of little Daisy Armstrong, Bouc exclaims,“Ah! quel animal!” M. Bouc’s tone was redolent of heartfelt disgust. “I cannot regret that he is dead—not at all!”

At the end of the book, Poirot presents two solutions to the crime. One solution clearly shows that Daisy Armstrong’s friends and relatives killed Casseti. The other solution acquits them of the crime. It is clear that M. Bouc has no sympathy for the dead man and can understand what motivated his murder. Poirot says to Bouc:

“You are a director of the company, M. Bouc,” he said. “What do you say?”

Bouc cleared his throat.

“In my opinion, M. Poirot,” he said, “the first theory you put forward was the correct one— decidedly so. I suggest that that is the solution we offer to the Jugo-Slavian police when they arrive.”