Kate and Betty Hadley team up, again, with Boston police detectives, Joe Talbot and Casey Roach, to find out how a valuable, antique document got into an old copy of a popular book. Who does the document belong to and why did it get there? Not being detectives, the socialite sisters use their spunk, social contacts, and the daily newspaper, to find their way through a maze of plausible owners before finding the real one.