The Mysterious & Unknown series walks a fine line, presenting information that a student could use to write a report without throwing too much cold water on good old-fashioned, shivery stories. They end up leaning more on the side of stories, although they do cite where the information comes from in chapter notes. Prophecies and Soothsayers discusses the people who try to predict the future from animal entrails in Roman times all the way up to modern-day doomsday prophets. Its coverage of biblical prophets is a weak spot, with almost all of the attention devoted to retelling Revelations. Each book includes drawings, etchings, photographs, and other artwork, though the sidebars and boxes sometimes repeat information from the main text rather than extend it.