This book is considered by many people to be one of the best mysteries ever published. In my opinion it ranks right up there with Conan-Doyle's Hound of the Baskervilles, as a mystery. Agatha Christie relied on the convolutions of unraveling a mystery to motivate and pull a plot, along with a great many red-herrings.In this Mystery she employes one of the cleverest and rather subtle red-herring ever in a mystery.I warmly recomend this mystery. Its well written, well paced and exceptionally clever.The ending will shock you.