This is the first Agatha Christie novel I read, and the second mystery author I've been introduced to, and it's going to be adapted into a new movie! 
 Hercule Poirot, our novel's detective, travels for an assignment aboard the Orient Express which runs from Paris to Istanbul. Some of his fellow passengers were the Director of the Compagnie Internationale des Wagons-Lits (the company owning the train), who is an old friend, a strange millionaire called Samuel Ratchett and his entourage, and a couple of foreigners of various nationalities - English, Swedish, American, Italian, Hungarian, etc. Ratchett asks a favor from Poirot, which the latter doesn't do, as he does not like the millionaire's face. Then one night, there was a heavy snow storm which halted the train's travel, and Ratchett is found dead. 
 Fun fact: Christie's inspirations for her books come from her own personal experiences and real events. She actually did ride the Orient Express, and some of the incidents were based from a true crime. 
 Like in a Sherlock Holmes story I've read, Agatha Christie emphasized on another form of Justice in "Murder of the Orient Express". (I won't tell why, because it would ruin the excitement.) As I read the book, I was looking for clues as to what happened, and then the two Big Reveals: the identity of the victim (because in detective stories, knowing the victim means knowing also the murderer) and the solution to the mystery. To be honest, when I read this the first time, I got impatient and skipped to the end. Not because it was so boring, but because Christie cleverly hid things until the very end, and I want to know already. That's how good she is. 
 This remains to be one of my favorite Christie novels, and I've been told by a professor in my Literature subject that this was the best and the most memorable mystery Christie penned. And it really is. (The other one that was equally devious and brilliant was And Then There Were None, but that's for another time.)