How we cite our quotes:
Quote #7
"Nonsense. It's absurd. Colonel Arbuthnot is the last man in the world to be mixed up in a crime – especially a theatrical kind of crime like this." (2.15.165)
Christie gives us hint after hint that the reality we are presented with in the novel is not, in fact, reality. The word "theatrical" is a clue here
Quote #8
"That is all very fine," said M. Bouc. "But what have you to go upon?"
"I told you just now. We have the evidence of the passengers and the evidence of our own eyes."
"Pretty evidence – that of the passengers! It told us just nothing at all."
Poirot shook his head.
"I do not agree, my friend. The evidence of the passengers gave us several points of interest." (3.1.13-17)
While M. Bouc and Dr. Constantine remain puzzled, Poirot has made observations that suggest a simple solution to the mystery.
Quote #9
"I came to the conclusion that the whole business at twenty-three minutes to one was a comedy played for my benefit!" (3.9.50)
Christie's novel again suggests the theatricality of the crime here as Poirot likens the events to a comic play. Just like in a play, all of the people on the train are acting out roles.