Five 1920s scenarios for Call of Cthulhu, each set in or around a large building. - Mr. Corbitt - The Plantation - The Crack'd and Crook'd Manse - The Sanatorium - Mansion of Madness From the back cover: MANSIONS OF MADNESS is a new collection of five independent tales set in the 1920s. Of varying length and complexity, these adventures can be planted into an ongoing campaign as the keeper sees fit. Some can be played in a single night; others will require several nights to complete. They can readily be used as plot twists, interesting diversions, or red herrings.