Set in rural Pennyslvania in the 1760s, this tale of horror and mystery is based on an actual case of a New York farmer who murdered his family. The author employs Gothic devices and sensational features such as spontaneous combustion, ventriloquism, and religious fanaticism. Fiendish Carwin uses his influence over Clara Wieland and her family, destroying the order and authority of the small community in which they live. The novel examines some fundamental issues crucial to the survival of democracy in the new American republic. The unfinished sequel, Memoirs of Carwin the Biloquist, traces Carwin's career as a follower of the utopist Ludloe.