Rufus King: 30 books

Ann Lebrick cheerfully accepted an assignment to photograph the ocelots of Miss Estelle Marlow. On arrival at the Marlow estate, Black Tor, where she was to stay for a week, she found herself in a brooding atmosphere of great wealth, guarded isolation from the rest of mankind, and black clouds of suspicion....

The story of two stepbrothers and the $3 million that came between them. It is also in the pure tradition of the inverted detective story: told from two opposing viewpoints, one the murderer's, the other the detective's (in this case, Stuff Driscoll). It's also scrupulously fair to the reader.