Mr. and Mrs. Barry Langmore were murdered in their home. Their daughter, Margaret, and Mary Billings, a servant, were the only people known to be in the house with the Langmore's. Margaret is suspected. Raymond Case, who was in love with Margaret, enlists the aid of Adam Adams, the detective, to solve the case."Chester K. Steele" was a pseudonym used by the Stratemeyer Syndicate, the company which created and wrote many series books including The Hardy Boys and Nancy Drew. This book, the first in the series, was actually written by Edward Stratemeyer, the head and owner of the syndicate, himself.