Well that was a disappointment. They were all guilty, and they each took turns in stabbing the man.
I'm sorry but it just strikes me as unbelievable. A little foolish, especially as there were strangers such as Poirot on the train. I was also admittedly bored by the first ¾ of the book, and it only got interesting as Poirot started to make observations that felt truly meaningful. There wasn't enough action in the text, and I personally didn't find the scenes particularly descriptive. Overall, it doesn't entice me to read much more of Christie's work. Perhaps And Then There Were None will be more enjoyable for me.