Pertwee portrays the Third Doctor as a dapper man of action in stark contrast to his wily but less action-orientated predecessors. While previous Doctors' stories had all involved time and space travel, for production reasons Pertwee's stories initially depicted the Doctor stranded on Earth in exile, where he worked as a scientific advisor to the international military group UNIT. Within the story, the Third Doctor came into existence as part of a punishment from his own race, the Time Lords, who forced him to regenerate and also disabled his TARDIS. Eventually, this restriction is lifted and the Third Doctor embarks on more traditional time travel and space exploration stories.