An influential banker informs the police that he is being blackmailed by Madame Hilary La Salle, operator of a very classy brothel. Apparently, she has been keeping a little black book — her "trick book" — containing details of all her clients. When Madame DeSalle is found murdered and the "trick book" goes missing, Pepper Anderson and Bill Crowley are called in to investigate. (thetvdb.com)