The show follows Guy Anatole, fresh out of law school and positioned for a bright future at a white-shoe firm in New York. He is approached and recruited by a mysterious woman who is a senior member of the Talamasca, a secretive organization devoted to surveilling the supernatural. As Guy is drawn further into this unknown world, he realizes he's been enlisted for a singular and perilous purpose: to go undercover into the Talamasca's London Motherhouse and unmask an agent who may be working with dangerous forces to bring down the entire organization from within, threatening the safety of the entire mortal world.