I have finished reading Agatha Christie's novel, Murder on the Orient Express, and I did not expect that ending at all. It ended with Mr. Poirot, the detective, stating two possible scenarios. One of those was the proposal that someone else had entered the train through the door that was left open, but no one really agreed with that and I didn't either. I was convinced it was somebody already on the train. His second answer, which blew my mind, came along by Mr. Poirot thinking that America was the only other place people of all
ethnicities could come together. He then began to guess that everyone on that train was connected to the Armstrong family. ALL of them had stabbed Ratchett. This completely blew my mind.
As for symbols and themes in the novel, there were definitely a few. A theme is Justice by Jury. Colonel Arbuthnot was a strong believer in the jury system, and this explains how they killed him. There were 12 attackers, 12 stab wounds, and there are 12 people on a jury. Technically, they all gave him his "justice" by sentencing him to death.

A symbol is Samuel E. Ratchett. He represents pure evil in the book, since he killed little Daisy Armstrong, who is the symbol of good and innocence.
Overall, I really enjoyed this book. I would definitely recommend it to anyone searching for a puzzling and gripping novel that keeps them on the end of their seat.