Okay, I think this one is pretty well-known: Murder on the Orient Express, by Agatha Christie. Hercule Poirot, a Belgian detective who works in London, has just finished solving a case for the French Army in Syria, and is now on his way back home, though he plans to spend a few days sight-seeing in Istanbul. In Istanbul, he receives a telegram that a case in London that’s been on the backburner has just had a big breakthrough and he needs to hurry back.
He books a ticket on the Orient Express, and is surprised to find all the sleeping car is filled. This is unusual because it’s deep winter, when the train is usually not full. Even his friend, Monsieur Bouc, an official in the train company who happens to be riding with him, is not able to get him a sleeping berth. Only when a passenger doesn’t show up at the last minute is Poirot able to secure a place.
It’s an unusual collection of people riding, from all over–Americans, English, Italians, Swedes–all of whom coincidentally wanted to take the train at the same time. After Poirot goes to sleep, he hears a shout and a muffled thump against the door. He looks in the passageway and sees only a woman in a scarlet kimono (though he can’t see her face) and the conductor for the sleeping car, who seems to be taking care of matters. Later, Poirot realizes the train has stopped and hasn’t moved for some time.
In the morning, he wakens to discover first that the train is stuck in a snowdrift in the mountains in Yugoslavia–it could be days before they get moving again, and second, that one of the passengers has been murdered. The murderer must still be on the train. At Monsieur Bouc’s urging, Poirot agrees to take the case, and begins searching for clues and interviewing the passengers. Of course, it would be nice to find the murderer, in case he (or she) plans to strike again….
This is one I’d never read, although of course I knew the famous ending ahead of time. (I won’t give it away for those who might not have heard.) Still, the twists to get there were well worth reading, with plenty of false leads and clues hidden in plain sight. Monsieur Poirot specializes in psychological analysis, and the way he gets the truth out of those who might wish to hide it is ingenious. All in all, a fun novel with a lot of style.