Except for the first book, which contains thirteen, all the books contain ten mini-mysteries similar to the "Encyclopedia Brown" books. Each mystery ends with a question to answer, and a picture of the checklist from the game is provided to assist with solving. The answer is printed upside-down on the next page, providing an explanation of how the criminal was foiled, or how the victim (if there was one) survived. The first nine mysteries typically involve some sort of competition between the guests (in which case readers must deduce who won), a guest attempting to murder another guest, or some sort of rare treasure of Mr Boddy's that has been stolen. Deduction of the guilty party is done by tracking particular oddities given specific to the mystery, such as the guests all trying on specific scents of perfume or a note that some are wearing a particular style or color of clothing. The guests also have very distinct, exaggerated personalities that betray their identities to the reader when they are not directly named.