Media franchises tend to cross over from their original media to other forms. Literary franchises are often transported to film, such as Sherlock Holmes, Miss Marple, and other popular detectives, as well as Superman, Spider-Man, and other popular comic book superheroes. Television and film franchises are often expanded upon in novels, particularly those in the fantasy and science fiction genres, such as Star Trek, Doctor Who and Star Wars. Similarly, fantasy, science fiction films and television shows are frequently adapted into an animated television series or a video game, or both.