Any list of all-time great mystery novels will probably include Agatha Christie's 1933 novel,"Murder on the Orient Express". The novel was written when Agatha Christie was at her prime and it featured her famous fictional detective, Hercule Poirot.
Most people, I would suppose, are more familiar with this story as a result of the 1974 movie version of this story. This movie was directed by Sidney Lumet, and it starred Albert Finney as Poirot, a role for which he was nominated for the Best Actor Oscar, and an all-star cast that included Ingrid Bergman, who won the Oscar for Best Supporting Actress for her role in this movie.
In the story, Poirot finds himself a passenger on a filled to capacity passenger coach on the Istanbul-to-Calais Orient Express on a three day trip across Europe. On the first might out, two significant events take place. The train hits a snowdrift and and is stranded somewhere in the middle of the Balkans, and one of the passengers is brutally murdered in his compartment, which is right next to Poirot's compartment.
The murdered man's compartment is locked from the inside, the victim's watch is broken so the time of death can be firmly established, a pipe cleaner is found on the floor of the compartment, as is a conductor's uniform button, but no one on the Calais Coach had any motive or reason to murder the dead man. Or did they? A railroad official also traveling on the train asks Poirot to take on the case and determine a solution before the tracks are cleared and the local police can reach the train.
The solution to the mystery is what has made this one of Christie's most famous books and why it occupies so many "Best Mysteries" lists. However, this may be one case where the movie that was made from this novel actually outshines the book. I have read this book several times over the years, but it has probably been at least thirty-five or so years since I last read it, and what I read this time did not hold up to my memory of my enjoyment of the book the first time that I read (which I did well before the movie was produced). How Poirot reached his conclusions involved some seemingly incomprehensible leaps of reasoning at times. I also thought that the phrasing sometimes seemed arcane, and Poirot's frequent use of French phrases was a bit annoying.
If you have neither read this book nor seen the movie, I would highly recommend that you do both, but read the book first. For someone who knows only the 1974 film version of this story, the book might prove to be a disappointment.