Original vintage Australian Daybill movie poster with Norman McMurray artwork. X The Unknown is a British science fiction horror film made by the Hammer Film Productions company released in 1956. It stars Dean Jagger, Edward Chapman,Leo McKern and was written by Jimmy Sangster. The film was directed by Leslie Norman. The film is significant in that "it firmly established Hammer's transition from B-movie thrillers to out-and-out horror/science fiction.