Frank Gideon was a private investigator whose life was forever changed when he took a case from Professor Wilbur Hammington at Falcraft University to recover scrolls stolen from the university museum. He discovered they were taken by a cult, The Order of the Crescent Moon. They thought it would allow their high priest to become the avatar of the demon they worship, Darkmoon. Interrupting the ceremony Frank was bonded to the demon, who was slowly taking control of his body. Hammington tries to help him sever his connection to Darkmoon while the Order seeks to stop them so the demon can be free.