If "Rue Morgue" was the first true detective story in English, the title of the first full-length detective novel is more hotly contested. Two books by Wilkie Collins--The Woman in White (1859) and The Moonstone (1868)--are often given that honor, with the latter showing many of the features that came to identify the genre: a locked-room murder in an English country house; bungling local detectives outmatched by a brilliant amateur...