Unbound Master

A version of the Master from a parallel universe was a Time Lord exiled on Earth.

Biography
Having had his TARDIS placed beyond his reach, the Master spent his time stuck on Earth through the 1970s right through to 1997 when the Doctor was sent to Earth by the Time Lords. He worked for the United Nations and then defected to China after being sent there to assist against alien parasites. He turned the parasites into a way of brainwashing political prisoners into zombie-like soldiers organised into Ke Le Divisions.

Losing favour with the new Chinese government in 1997, he fled to Hong Kong to allegedly defect back to the West. He regenerated when he crashed an experimental cloaked plane on Hong Kong, and tried to gain the last of the parasites. He was rescued by Adam, but the Master then proceded to kill and steal his garments, including an Union Jack tie. China intended to wash their hands of the Ke Le Divisions by destroying the other parasites. The Master realised this would cause the Divisions to go insane under the weight of their returned memories; with the last parasite, he intended to seize control of the Divisions and the country ("I'll save the world from anarchy overnight").

When the Doctor arrived, the Master showed a genuine bitterness at having to live on an Earth where the Doctor hadn't been present for thirty years; he brought up scores of atrocities that the Doctor had failed to stop, accusing him of letting entire cultures and races die from missing the big picture, choosing the wrong sides, and simply not turning up. Eventually, he agreed to help the Doctor and UNIT destroy the last parasite - allowing them to believe nothing bad would happen - in return for being taken off Earth in the TARDIS, while secretly planning to betray everyone. Unfortunately for him, the Doctor had anticipated this and tricked the Master into being left in Hong Kong as the TARDIS departed.

In a desperate attempt to be evacuated from the city, he admitted to UNIT's Colonel Brimmicombe-Wood that the Ke Le Divisions would go insane once the last parasite was destroyed. By this point it was too late, and the Master was last heard giggling as the Divisions massacred Hong Kong. (AUDIO: Sympathy for the Devil)

The Doctor heard his voice when he was captured by the Library. (AUDIO: The Library in the Body) He posed as the Manager of the shop at the Gateway to the universe. He created a lottery which had a prize to get out of this universe. He knew that Bernice Summerfield didn't belong to his universe and paid attention to her. He wanted to send Benny back to her universe in order to create a permanent bridge between their universe to send everyone in the universe. In fact he was using the energy of the people in the universe to allow himself to go through the universe. (AUDIO: The Emporium at the End)

Behind the scenes

 * The character is called "Ke Le" on the case.
 * This version of the Master was played by Mark Gatiss, using the anagrammatic pseudonym "Sam Kisgart". This was a reference to the use of anagrams to hide Anthony Ainley's appearances in several stories in the 1980s.
 * Mark Gatiss also portrayed an incarnation of The Doctor who appears in the comedy sketch The Web of Caves. Along with Derek Jacobi, this makes Gatiss one of only two actors to have portrayed both the Master and the Doctor in licensed, although not canonical, appearances.
 * Jonathan Clements, author of Sympathy for the Devil, voiced the dying previous incarnation of the Master in that story.