From the publisher's Site: The 40th Anniversary edition of the Call of Cthulhu Keeper Rulebook contains the core rules, background, guidance, spells, and monsters of the game. It is everything you need for Call of Cthulhu at your fingertips. The 40th Anniversary edition of the Call of Cthulhu Keeper Rulebook is presented in a pristine black leatherette cover, with red embossed sigils and designs. In addition to the rules, the book includes: A never-before-printed collection of essays, forwards, and musings from a wealth of Call of Cthulhu writers including Penelope Love, Lynne Hardy, Mike Mason, Mark Morrison, Paul Fricker, and more. The classic scenario The Haunting, in which the players are recruited to investigate a supposedly haunted house in 1920s Boston.