To be honest I could have put almost any Christie novel in this list, because for me the pleasure in reading them is pretty consistent. I love her for all the reasons that other people dislike her: the artificiality of her characters, the mechanical nature of the plots and the circumscribed world in which they take place. To me, detective fiction is all about creating a beautiful machine: you switch it on on page one, and it keeps working till the end. I don’t want extraneous nonsense like character development and moral ambiguity; I can get that elsewhere. So while I like Ngaio Marsh, Dorothy Sayers et al, Christie will always be the queen. I chose The Body in the Library because a) it was the first Christie I read and loved, b) it features Miss Marple who is one of my favourite fictional characters of all time and c) well, how could I resist a murder mystery set in a library?