There isn't really an adventure at all. After about five chapters, with the world's longest traveling train, Hercule Poirot is given a deal with an American named Samuel Ratchett, and in the first night, there are a few weird noises that aren't really definable, and in the morning, this man has been stabbed in the chest, not once, but a dozen or so times. No footprints are in the snow, so Poirot and his helper go with the conclusion that whoever is the murderer is still on the train. I didn't like that part, knowing there are other ways to get off a train through a window. THere's also a handkerchief, a pipe, a note, and a few other things too that won't lead to anything without interviews with the passengers. Each of these folks are special characters with so much to say about themselves, that Agatha Christie put a chart of each person in the book, before the story. Act 2 goes through a day of finding a hundred different things about everyone, which will consume a lot of patience if you have to read it for a book report like I had to.
This book is an oldie, and the problem that I had with that wasn't that it was too long, it was brief enough, but some of these ideas Poirot had about solving the mystery were obnoxious, expecting people to have a personality based on their culture, like how we Canadians say Sorry a lot, or how in France, kids call their teachers by their first names. The ones in these though, express Americans and British in an even more bizarre way, like how he says that when he arrived, there was a group that had a discussion with their first names, which according to him, meant they were in love. Still, it's a very edgy way of telling the mystery, and it's not all about that. There's also some parts in the mystery that are super clever, like when Poirot reveals that he told a man about a note, he muttered, "But surely," showing that he knew about the note and it was meant to be destroyed. So who killed Samuel Ratchett and was stupid enough to stab him a dozen times? No way am I revealing it, but you'll feel, "Why didn't I think of that?" at the end.