Italian horror written and directed by Dario Argento. Peter Neal (Anthony Franciosa) is a mystery writer in Rome to promote his new novel. His stay is disturbed by a crazed maniac who begins a terrifying murder spree, stuffing his victims' mouths with pages from Neal's books. With the death toll continuing to rise and the police struggling to find any leads, Neal and his assistant Anne (Daria Nicolodi) begin an investigation of their own. The cast also includes John Saxon, Guiliano Gemma and Christian Borromeo.