Peter Lovesey 
False Inspector Dew [EPUB ebook] 

It is 1921, and Alma Webster, a reader of romances, is passionately in love with her dentist, Walter Baranov. There is only one foreseeable outcome: the murder of his wife. Inspired by the real-life Dr Crippen case, they plot a way to achieve it perfectly aboard the ocean liner, Mauretania. With a fine sense of irony, Baranov takes the identity of Inspector Dew, Crippen’s nemesis. But when a murder is reported aboard the ship and 'Inspector Dew’ is invited to investigate, the complications begin.Listed in The Times’ 100 Best Crime Novels of the Twentieth Century.