As an erstwhile devotee to the works of Agatha Christie, one thing became very apparent very quickly: the sheer body of work is enormous and very difficult to navigate, not only because most of the books are quite old, but because of the range of different characters. We have the better-known Hercule Poirot, Miss Marple and so on, but if one of Christie's characters is your favourite how on Earth do you go about locating them in order? This book is...