M is for... Master (7) - Missy

The Doctor's next encounter with the Master, after he had thwarted Rassilon's attempt to draw Gallifrey out of the Time War, came in his Twelfth incarnation when he was accompanied by Clara Oswald. She had been in a female form since his Eleventh incarnation at least - as it had been as a woman that she had brought the two together. Calling herself "Master" was no longer appropriate to her new gender, so she retitled herself Missy - for Mistress.

Clara had rung an IT helpline, and Missy had given her the number for the TARDIS phone.

Still in male form - his "Harold Saxon" incarnation - the Master had been forced to leave Gallifrey. He took a piece of Time Lord technology with him - a Matrix Data Slice. This created and maintained an artificial environment within itself. After becoming stranded on a colony spaceship from the planet Mondas, the Master had encountered Missy - the future version of himself - and the two had attacked each other. Dying, he made it back to his TARDIS but regenerated into the very incarnation who had just "killed" him.

The trauma of this event somehow caused her to forget the circumstances of her regeneration.

Having been shunned by the Time Lords, Missy sought to forge a new relationship with the Doctor. 

Her plan involved monitoring the Doctor's activities for some time, whilst uploading the minds of those who died as a result of his adventures into the Matrix environment, which she named the Nethersphere. She and an AI called Seb welcomed them to what they claimed was the afterlife.

When Clara's boyfriend Danny Pink was killed in a road traffic accident, she attempted to force the Doctor to change history and bring him back. He refused, but decided to see if the TARDIS could locate where he had gone. Clara would link with the ship's telepathic circuits to take them to him.

They arrived not in "heaven" but in the 3W Institute - a huge funerary complex. Missy appeared, pretending to be an AI interface. Like the Doctor she had a Scottish accent. The Doctor recognised the Time Lord technology, however.

The 3W Institute proved to be full of Cybermen. Missy was downloading the minds of the recently deceased from the Nethersphere into their bodies, creating a new army of Cybermen loyal only to her.

She revealed her true identity to him, but was then captured by Kate Stewart and Osgood of UNIT.

Whilst being transported on UNIT's command aircraft, Missy escaped and murdered Osgood before having the 'plane attacked and destroyed by Cybermen.

When the Doctor confronted her in a graveyard in England, Missy unveiled her scheme. She had created the Cyber-army as a present for him - so that he could use it to help him fight injustice throughout the universe. He would no longer have to struggle alone.

The Doctor rejected the gift, and an unconverted Danny took charge of the Cyberman army, ordering it to destroy itself. The Doctor stopped Clara from killing Missy, but she was apparently destroyed by a surviving Cyberman - one which contained the mind of Kate's father. Just before this, as a means to save herself, Missy had claimed to know the location of Gallifrey - but when the Doctor went there he found that she had lied.

Missy had not been killed, however, having managed to teleport herself away at the last moment. She reappeared some months later, when she used a stasis device to suspend time for every aircraft in the skies above the planet. This was simply her way of attracting the attention of Clara, who had gone to UNIT when the event took place. The Doctor had recently disappeared. He had left his Confession Dial with Missy, and she wanted Clara's help in tracking him down. This Dial contained a Time Lord's final thoughts, and was operated only when its owner expected to die. Also seeking the Doctor at this time was Davros, who had sent his security chief, the serpentine Colony Sarff, to seek him out.

Missy had been traced to a Mediterranean island, and UNIT transported Clara there. UNIT were able to trace the Doctor to medieval England, and Missy took Clara there using a Vortex Manipulator.

The Doctor has been hiding here, delaying his inevitable confrontation with the creator of the Daleks.

Colony Sarff traces them due to a Dalek agent at the castle where the Doctor has been staying. 

All three were captured and transported to Skaro. Missy was, once again, apparently destroyed by the Daleks - but she had simply transported herself out of the Dalek city with Clara at the last minute. Missy was using Clara as a means to protect herself from traps - pushing her into danger before herself. They decided to break back into the city via its sewer system. Daleks flushed the dying members of their race down here. Missy arranged for a Dalek guard to be overpowered by the still living remains, and had Clara hide inside the empty shell to gain access to the city.

The Doctor managed to defeat Davros' scheme to steal his regeneration energy. Missy tried to get him to destroy the Dalek containing Clara - claiming it had killed his companion - but he was able to spot the ruse and free her. As the city was destroyed, Missy attempted to ally herself with the surviving Daleks. The Doctor and Clara fled the planet, leaving her behind.

Some time later, when the Doctor was now travelling with a young woman named Bill Potts, he was summoned to an obscure alien planet to witness the execution of Missy. As the only other living Time Lord in the universe (Gallifrey being stranded in a pocket of time at the end of the universe), the Doctor found that he had to act as her executioner. He agreed to stand guard over her tomb for a period of one thousand years. However, he sabotaged the execution so that she was merely rendered temporarily comatose. The Doctor would still honour his promise, but would now be guarding her prison rather than her tomb for a millennium. He had the vault installed in the basement of St Luke's University in Bristol, where he based himself as a lecturer, with Nardole as his servant. He was an ex-husband of River Song, and the Doctor had provided him with a new body after he had lost his head to a giant robot.

Earth was invaded by a race of mysterious Monks who altered people's memory of history to make themselves a constant part of it - benevolent helpers of the human race over the millennia. Bill had allowed them to take over, in exchange for them restoring the Doctor's sight. Seeking a way to overthrow them, the Doctor, Nardole and Bill entered the vault to consult with Missy. She revealed that she had encountered them before, and the only way to break their mental hold was to kill the person who had given them permission to invade. This is what she had done - pushing a child into a volcano.

Bill used powerful memories of her dead mother to overpower the Monks' control instead, and they were forced to flee the Earth.

The Doctor and Bill were later stranded on Mars in Victorian times, and Nardole took the decision to free Missy so that she could pilot the TARDIS to come and rescue them.

The Doctor then decided to try to rehabilitate Missy whilst she remained his captive. This involved her confronting the actions and behaviours of the humans whom she had frequently sought to destroy or conquer, so that she might better understand them - and why the Doctor loved them so much.

The Doctor's programme saw him allowing Missy to take charge of the TARDIS and go exploring, with Bill and Nardole as her companions. He would accompany them, but remain on the ship and observe only. However, after landing on a massive colony ship beached on the edge of a Black Hole, Bill was mortally wounded. The Doctor had to intervene. Missy identified that the ship had originated on the planet Mondas, home of the Cybermen. Bill had been cared for by a man named Razor, in a section of the ship which was moving at a much faster timeframe than the control room where the TARDIS had materialised. Razor travelled up to this level and met with Missy - revealing himself to be her previous incarnation in disguise.

United with her former self, he quickly began to undermine all the work which the Doctor had done to rehabilitate Missy - reminding her of her true nature.

She quickly reverted to her old ways, helping the Master attempt to kill the Doctor. When he sought their help in defending a community of humans from attack by Cybermen, both rejected him. Missy gave the Master a spare dematerialisation circuit to replace his damaged one - the result of a memory of her having advised him to carry one. This would allow him to repair his TARDIS so that they could both escape the colony ship together. However, neither trusted the other. Missy had taken on board some of what the Doctor had taught her, and was wavering in her decision to run away. She had also come to hate her former self. He, in turn, hated what the Doctor had done to his future incarnation, and determined that it should never happen. Their distrust of each other resulted in them attacking and mortally wounding each other. The Master had attacked Missy in such a way that she would be unable to regenerate this time...

Played by: Michelle Gomez. Appearances: Deep Breath, Into The Dalek, The Caretaker, Flatline, In The Forest of the Night, Dark Water / Death in Heaven (2014), The Magician's Apprentice / The Witch's Familiar (2015), Extremis, The Lie of the Land, Empress of Mars, Eaters of Light, World Enough And Time / The Doctor Falls (2017).

• Michelle Gomez was an old friend of Peter Capaldi, having grown up in Glasgow as he had.
• Her surname comes from her Portuguese father. He was born on Montserrat.
• Her earliest TV roles, which brought her to the public's attention, were comedic (such as the hospital-set Green Wing).
• She is married to actor Jack Davenport (of The Pirates of the Caribbean fame).
• Steven Moffat decided to sow Missy's presence throughout the whole of Series 8, with a few short coda scenes where she would encounter someone who had been killed in the preceding adventure. In The Caretaker, she simply passes through a scene involving Seb and a dead policeman, and in In the Forest of the Night, she is observing what the Doctor and Clara are up to.
• When we learn of her real plan, we have to wonder how the robot Knights and the Half-Face Man fit, if they have no human minds to upload to the Nethersphere.
• When she first meets the Doctor, pretending to be a hologram, Moffat teases the viewers by having her call herself a Random Access Neural Integrator - R.A.N.I.
• Clara mentions a woman on an IT helpline, who gives her the Doctor's phone number, back in The Bells of St. John. Fans at the time assumed this to refer to River Song.
• It transpires that it was Missy who also put the adverts in the newspaper which brought the newly regenerated Doctor and Clara back together in Victorian London in Deep Breath.
• Missy mentions a few events to Clara relating to her past and that of the Doctor, but it is difficult to know which, if any are true. It isn't clear either which incarnation she is talking about - such as claiming to have a daughter.