This novel is actually a collection of short stories involving four villains that seem to come straight from a James Bond movie. The group is known as "The Big Four" (funny title for the 5th Poirot novel) and Poirot has the help of the not-so-intelligent Hastings to figure out who is who and defeat the evil organisation.

I understand why people do not enjoy this novel as much as the others, but I also understand that Christie wanted to try and write something different. She is not great with short stories, so it is not surprising that this collection turned novel is not her best work. I have to give it to her for trying different story lines though.