M is for... Master (8)

Quite how Missy survived her death at the hands of her earlier incarnation remains a mystery - but survive she did, to regenerate into another male form of South Asian appearance.

The Master infiltrated the British security service MI6 after killing one of their staff and assuming his identity. Codenamed "O" he gained a reputation as a bit of a loner, with his own idiosyncratic way of working, basing himself in the remote Australian Outback. He developed a keen interest in extra-terrestrial threats, and came into contact with the Doctor, who maintained regular communication with him.

The Doctor was called in by "C", head of MI6, when a number of agents around the world came under attack. They had been left in a comatose state, their genetic make-up drastically altered. "C" was then assassinated and the Doctor and her companions headed for Australia to seek "O"'s help. Together, they discovered that the beings behind the attacks were extra-dimensional - the Kasaavin. They seemed to be working with an IT entrepreneur named Daniel Barton, who had once worked for MI6.

On sneaking aboard Barton's private aircraft, the Doctor discovered that she and her companions had been lured into a trap. "O" revealed his true identity after giving himself away. He had claimed to be a poor sportsman, whereas the Doctor knew that "O" had won medals for running. His house had been his disguised TARDIS, which was shadowing them by remote control.

The Doctor was transported to the domain of the Kasaavin, but met there Ada Lovelace, the scientist daughter of Lord Byron. She helped the Doctor escape to Victorian London, but the Master followed. He had reverted to using his tissue compression weapon, which shrank its victims. The Doctor and Ada fled to Nazi-occupied Paris, but the Master followed - using a perception filter to look Caucasian and adopt the role of an SS officer.

Knowing that he would be hunting for her again, the Doctor broadcast a message based on the four beats of a Time Lords' heartbeat. The pair met atop the Eiffel Tower. He discussed his plan with her, revealing his intention of dropping the Kasaavin at the earliest opportunity to take control himself. 

The Doctor escaped after luring a squad of German soldiers to the Tower, and disabling the Master's perception filter. He was captured, and the Doctor stole his TARDIS to get Ada back to her time, and return to the 21st Century to find her companions. The Master's scheme had been, with Barton's help, to use his IT technology to rewrite human DNA - turning people into walking hard-drives for use by the Kasaavin. The Master reappeared, revealing that he had been stuck on Earth and forced to live through its history for the last seven decades. The Kasaavin arrived, but the Doctor had recorded the Master's comments atop the Eiffel Tower. With their scheme already wrecked through the Doctor's sabotage, Barton fled, but the Master was captured by the Kasaavin and dragged off to their extra-dimensional domain, where he would remain trapped.

Back in her TARDIS, the Doctor discovered a holographic message left by the Master. He revealed that he had discovered some great secret of the Time Lords - one so terrible that it had driven him to destroy Gallifrey. The Doctor travelled to her home planet and found the Capitol a lifeless ruin. The Master had been telling her the truth...

Some time later, the Doctor became involved in the Cyberwar. By this stage, she had encountered an incarnation of herself which seemed to predate that of her earliest memory - one who worked for a shadowy militaristic organisation operating out of Gallifrey, but who had run away.

The Cybermen had a new leader named Ashad, who still retained human emotions after being only partially converted. Under his leadership, the Cybermen had over-run the galaxy and almost wiped out the human race.

On an obscure planet, a man named Ko Sharmus was helping the survivors escape to worlds which were free of the Cyberman threat. The Doctor and her companions arrived there along with a handful of survivors, and learned that Ko Sharmus oversaw a strange space-time portal. When it opened, the Doctor was amazed to see Gallifrey beyond it. The Master suddenly appeared through the portal, and forced the Doctor to accompany him to her ruined homeworld.

He took her to the remains of the Panopticon where he captured her in a forcefield, and then proceeded to explain what he had discovered - and why he had destroyed Gallifrey. Hidden deep within the Matrix he had found a secret history which had been withheld from their people for millennia. The Doctor was really a being from another universe, who had been found as a child by an early Gallifreyan explorer and scientist - Tecteun. She had brought her back to her home planet, where she later witnessed the child's apparent death in an accident. However, the child had regenerated and survived, adopting a new male body in the process. After years of experimentation, Tecteun was able to reverse engineer this regeneration process for her own people. The Time Lords owed their ability to regenerate to the Doctor, who wasn't a native Gallifreyan at all, but a being from an unknown dimension - one who was actually immortal.

The Master could not stand the truth that he owed his very existence to his old enemy, and loathed the way the Time Lords had lied to their people all these years.

He then decided to draw the Cybermen through the portal, contacting Ashad and offering him his help.

Ashad had planned to turn the Cybermen into purely robotic creatures - finally removing all trace of their humanoid origins. To this end, he had developed a weapon which could disintegrate organic matter - the Death Particle. When he learned that Ashad held this weapon within his own body, the Master used his TCE to destroy him - shrinking him whilst managing to keep the Particle intact.

Ashad had also held the Cyberium within himself - the artificial intelligence which was the source of all their knowledge and strategy. It needed a host to function, and transferred into the Master.

He then put his plan into action. He had retained a number of Time Lord bodies when he destroyed their cities, keeping them stored near the Panopticon. These he would combine with Cyber-technology to create a new race of Cybermen - ones with the ability to regenerate. These he named Cyber-Masters, and thanks to the Cyberium they would be loyal only to him.

The Doctor was able to obtain the corpse of Ashad with its Death Particle and threatened to detonate it after the Cyber-Masters had been created, sacrificing herself to do so. The Master doubted she would do this, whilst she suspected that he now had some kind of death wish. At the last moment, Ko Sharmus took her place and detonated the Particle.

However, the Master had managed to escape in a TARDIS with a number of Cyber-Masters. He then embarked on his most audacious scheme - to become the Doctor himself.

He inveigled his way into the Imperial household of Tsarist Russia by posing as a priest with special powers - Rasputin. This provided him with a base - the Winter Palace - from which to organise his scheme. This involved allying himself once again with the Daleks, who were to destroy the Earth by triggering many volcanic eruptions simultaneously across the globe. He attacked a meeting of leading seismologists and killed them with his TCE to prevent them interfering with this part of his plan. He then allowed himself to be captured by UNIT - attracting their attention after adapting a number of famous paintings with his own features. This was a ruse to gain access to UNIT's new HQ. His TCE could grow things as well as shrink them, and he had cloned Ashad and used him as a Passenger Form. Within was a whole army of Cybermen, who quickly over-ran the HQ.

The Cyber-Masters, meanwhile, had abducted a powerful alien Qurunx in order to harness its energies to power a Cyber-converted planetoid - and which would allow him to transfer himself into the Doctor's body via a process known as forced regeneration.

The Doctor was captured by the Daleks and handed over to the Master at the Winter Palace, and the transfer process initiated. The Master became the Doctor as she was forced to regenerate into him, whilst her personality was left in his old body, slowly being compressed out of existence. One of his aims was to destroy the Doctor's reputation by carrying out evil deeds in her new form. Her companion Yaz was forced to become his companion instead. He stopped a war between two planets by simply destroying them both, and ensured that this was observed by other races. He adopted an outfit based on a mix of earlier Doctor's costumes, as well as of her most recent incarnation. Yaz and another friend of the Doctor - Vinder - were able to capture the Master, helped by a hologram of the Doctor's hitherto unknown earlier incarnation. He was forced back into his transfer machine and the Doctor and he swapped back again, powered by regeneration energy from the defeated Cyber-Masters. He had revealed a great self-loathing - not wishing to revert to his old self. 

The Doctor then travelled to the Cyber-planet to free the captured Qurunx powering it. She encouraged it to destroy the Cyber-planet instead. The Master followed, dying from the reversal of the forced regeneration process. He was able to divert the Qurunx's destructive energies to strike the Doctor - mortally wounding her - claiming that if he could not be the Doctor then no-one would.

The Master appeared to perish as the Cyber-planet was destroyed...

Played by: Sacha Dhawan. Appearances: Spyfall (I & II), Ascension of the Cybermen / The Timeless Child (2020), The Power of the Doctor (2022).

• Dhawan, who was born in Stockport in 1984, came to fame as one of The History Boys - the school-set play by Alan Bennett which has produced a number of stars. It was turned into a movie, featuring most of the original stage cast.
• His partner is Anjli Mohindra - Rani in The Sarah Jane Adventures and the Skithra Queen in Nikola Tesla's Night of Terror.
• In 2013 he portrayed Doctor Who's very first director Waris Hussein in the 50th Anniversary drama An Adventure in Space and Time.
• He had previously worked with Jodie Whittaker in a 2008 TV series called Wired.
• He has guest starred in Sherlock, Dracula and Being Human, and was a regular on the Marvel series Iron Fist.
• This incarnation of the Master differs from others in that he seems to harbour a death wish, untroubled by being destroyed though only if the Doctor shares the fate. He is more openly jealous of the Doctor, and unhappy at his own existence.
• As the Master-Doctor his costume included elements from the Fourth, Fifth, Seventh and Tenth Doctors' outfits. He also plays a recorder like the Second incarnation.
• The Master had been seen to dance in his Harold Saxon incarnation. In The Power of the Daleks he dances to Boney M's Rasputin - to the surprise of the Daleks and Cybermen. Dhawan ad-libbed the dance moves himself.