Mystery of the Blue Train

This novel has a reputation for being on the list of "worst Agathas". Unfortunately, this is my only exposure to Agatha Christie's written work. I've been familiar with the more popular stories through TV, film and radio, it was nice to be read a story I've not seen or heard before. However where I expect to be able to follow clues, and deduce the crime along with the protagonist, I don't feel like I can, and the revelation at the end of the book feels like it's been plucked almost from thin air. The relationships of the cast are interesting, more interesting than the crime, but since there's a crime to solve, solved it must be.