The Second Confession — Rex Stout

When a millionaire businessman hires Nero Wolfe to probe the background of his daughter's boyfriend, it seems like just another case of an overprotective father. But when a powerful gangland boss "counsels" the detective to drop the matter, Wolfe realizes it's much more than that. Unwilling to take a hint, Wolfe receives a warning: a burst of machine-gun fire through the windows of his orchid room. Then the lawyer boyfriend turns up dead, leaving Archie the number one suspect. Throw in drugged drinks, two man killing debutantes, and officials of a highly un-American party and Wolfe finds himself involved in a case where he must quickly solve one murder to prevent another: his own.