The legendary Nero Wolfe is hired by a despicable millionaire named Otis Jarrell who is trying to prove that his daughter-in-law is an information-leaking, double-crossing snake. In spite of Wolfe’s reluctance, his assistant Archie brashly agrees to perform as Jarrell’s personal secretary - under an assumed identity - to gather information about the possible misdeeds of said daughter-in-law. Everything turns serious when one of the detectives' associates is found shot dead - and the evidence points to Jarrell’s own missing revolver.