Whose Body? by Dorothy Sayers
If Claire de Witt is a New Age detective, Lord Peter Wimsey is an old-fashioned one—a futsy, upperclass Englishman who also solves crimes. Sayers became famous for her later novels featuring Wimsey and Harriet Vane. Whose Body? is her debut effort and a good way to see what a master of mystery was like before she got famous (and, some would say, before she got really good).