While this incarnation spent most of his time exiled on Earth, where he grudgingly worked as UNIT's scientific advisor, he would occasionally be sent on covert missions by the Time Lords, where he would often act as a reluctant mediator. Even though he developed a fondness for Earthlings with whom he worked (such as Liz Shaw and Jo Grant), he would jump at any chance to return to the stars with the enthusiasm of a far younger man than himself. If this Doctor had a somewhat patrician and authoritarian air, he was just as quick to criticise authority too—having little patience with self-inflated bureaucrats, parochially-narrow ministers, knee-jerk militarists or red tape in general. His courageousness could easily turn to waspish indignation. It is thus no surprise that a common catchphrase of his was, "Now listen to me."
Despite his arrogance, the Third Doctor genuinely cared for his companions in a paternal fashion, and even held a thinly-veiled but grudging admiration for his nemesis, the Master, and for UNIT's leader, Brigadier Lethbridge-Stewart, with whom he eventually became friends. In fact, even when his much resented exile was lifted, the highly moral and dashing Third Doctor continued to help UNIT protect the Earth from all manner of alien threats.
Colour Magic and ExileEdit
The Third Doctor stories were the first to be broadcast in colour. The early ones were set on Earth due to cost constraints on the series. To explain this, the Second Doctor was banished to Earth by his race the Time Lords, and forced to regenerate. On Earth he worked with the Brigadier and the rest of the UNIT team. However, as his tenure progressed he had reasons to leave Earth, on occasions being sent on missions by the Time Lords. Eventually, after his defeat of the renegade Omega in The Three Doctors he was granted complete freedom by the Time Lords in gratitude for saving Gallifrey.