The bottom line: the film is good, but the book is better.
Renowned Belgian detective Hercule Poirot is traveling on the Orient Express when a murder occurs. He quickly determines that the victim, an American, was traveling under an assumed name and was really the infamous gangster Cassetti, responsible for the murder of an infant in America years earlier. With the train stopped due to an avalanche, Poirot has a captive group of suspects–each more suspicious than the last–and begins to interview them, methodically as is his custom, to determine which among them is the murderer.
While enjoyable, the film was not a stand-out. The cast is star-studded (and it’s convenient to have Johnny Depp in a role where you’re supposed to hate him) but ultimately, the film stepped a bit too far over the line toward melodrama. I blame Branagh. What I love from an Agatha Christie mystery is the suspense drawn out through carefully plotted revelations, perfectly dropped clues, and an overabundance of sinister characters to suspect. This was all certainly present in the film, and the acting was good. But we really didn’t need a gunfight. Just sayin’.