This is one of the few book club books that I finished reading. (Some day I'll go back and finish A Passage to India.) I had never read any of Agatha Christie's books though I am very fond of the BBC productions of Miss Marple and Hercule Poirot.
I was surprised that this book from the 1920s was just as easy to read -- and just as "modern" -- as many of the contemporary mystery novels I read. It was a bit short, but I think that's also typical of the time. I was willing to accuse different characters at different times. I was surprised that once "cleared" a character would wind up being suspected again. I think that was the twist that kept everyone on their toes.