The Heads of Cerberus is a dystopian science fiction novel by Francis Stevens (pseudonym for Gertrude B. Bennett)," The woman who invented dark fantasy ". One of the first dystopian novels, the book features a "grey dust from a silver phial" which transports anyone who inhales it to a totalitarian Philadelphia of 2118 AD. A vial of dust sends three unsuspecting friends to a dystopian Philadelphia, set in the twenty-second century. The novel was originally serialized as a five-part serial in the pulp magazine The Thrill Book from August 15 to October 15, 1919, and was first published in book form in 1952. A scholarly reprint edition was issued in 1978, and a mass market paperback by in 1984. Gertrude Barrows Bennett (1883–1948) was the first major female writer of fantasy and science fiction in the United States, publishing her stories under the pseudonym Francis Stevens. Bennett wrote a number of highly acclaimed fantasies between 1917 and 1923 and has been called " the woman who invented dark fantasy ". Her most famous books include Claimed! (which Augustus T. Swift, in a letter to The Argosy called "One of the strangest and most compelling science fantasy novels you will ever read") and the lost world novel The Citadel of Fear. Bennett has been credited as having "the best claim at creating the new genre of dark fantasy". It has been said that Bennett's writings influenced both H. P. Lovecraft and A. Merritt, both of whom "emulated Bennett's earlier style and themes".