3W Institute Affair

The 3W Institute Affair (PROSE: Missy on Trial) was the incident in which used the 3W Institute to create an army of Cybermen intended for the Twelfth Doctor.

Background
Though had escaped the Last Great Time War, (TV: Utopia)  returned to Gallifrey on the final day of the war after being embroiled in 's Ultimate Sanction. (TV: The End of Time) This last day ultimately ended when the planet, whilst besieged by the Daleks, was transported to a another dimension by the first thirteen incarnations of the Doctor. (TV: The Day of the Doctor) After being cured of his "little condition", the Master left Gallifrey in a "mutual kicking me out", eventually ending up on a Mondasian colony ship where he encountered his next incarnation,, in the company of the Twelfth Doctor. Refusing to allow Missy to stand with the Doctor as he defended the Mondasians from the Cybermen, the Master killed Missy after he himself was mortally wounded by her. Forced to regenerate, the Master returned to his TARDIS aware that he would lose most of his memory of this encounter. (TV: The Doctor Falls)

Missy decided to maneuver Clara Oswald into becoming the Doctor's companion, believing that Clara was just the right companion to attract the Doctor's interest and make it easier for Missy to emotionally manipulate him, (TV: Death in Heaven) showing him "the friend inside the enemy, [and] the enemy inside the friend." (TV: The Witch's Familiar) Ashildr believed that Missy placed the two together so that that the Doctor and Clara in tandem would become the Hybrid of Gallifreyan myth. (TV: Hell Bent) In 2013, Missy gave Clara the Doctor's phone number, claiming that it was a tech support line, leading Clara to meet the Eleventh Doctor. (TV: The Bells of Saint John, Death in Heaven) She then kept the Doctor and Clara together into the Doctor's twelfth incarnation by placing an ad in a newspaper for Mancini's Family Restaurant. (TV: Deep Breath, Death in Heaven)

Missy also founded the 3W Institute in order to create an army of Cybermen from the dead, (TV: Dark Water) whom she called her "Cyberdears", (PROSE: Meet Missy!) Needing to collect matrix slices that she had acquired in her previous incarnation, Missy travelled to London to receive them from her former wife, Lucy Saxon. (PROSE: The Unwanted Gift of Prophecy) Missy used the matrix data slices to create the Nethersphere, also known as Heaven and the Promised Land, where she uploaded dying minds to. This reality changed and rewrote the minds, removing their emotions before re-downloading them into their Cyber-converted bodies. (TV: Dark Water) Incidentally, the Doctor discovered that a ship of 29th century robots that had crashed in Nottingham of about 1190 had a programmed destination of "the promised land". (TV: Robot of Sherwood)

Missy went along the Doctor's timeline and greeted people who died in connection with him, (TV: Death in Heaven) such as the Half-Face Man, who had sought to enter the Promised Land, (TV: Deep Breath) and Gretchen Carlisle. (TV: Into the Dalek) Finding this made her "a bit busy", Missy had Seb, an artificial intelligence, greet new people (TV: The Caretaker) whilst she secretly monitored the Twelfth Doctor and Clara, (TV: Flatline) as she did when Earth was saved from a solar flare by a forest that grew overnight. (TV: In the Forest of the Night)

The incident
to be added

Aftermath
Following the destruction of the Cyber-Army, the Doctor went to where Gallifrey would have been in his universe as Missy had promised only to find nothing, much to his dismay. Two weeks following the incident, Clara was contacted by Danny, who told her that the Nethersphere was dying and as the bracelet only had enough power to send one person back, resurrected the boy whom he killed. Meeting up together, the Doctor told Clara that he had found Gallifrey whilst she told him that Danny had returned before they agreed to go their separate ways. (TV: Death in Heaven) However, both the Doctor and Clara were attacked by dream crabs causing them to meet each other in a shared dream with Santa Claus. There they learnt that they had lied to each other and ultimately decided to resume their travels in the TARDIS. (TV: Last Christmas)

Missy later revealed her survival to both Clara and UNIT, using a time stop to halt Earth's planes to get their attention as she'd received the Doctor's confession dial and needed their aid to track him down. The Doctor would later reveal to Clara he'd always suspected Missy had survived. (TV: The Magician's Apprentice) Following her containment in the Vault, (TV: Extremis) Missy would continue to try to win the Doctor's friendship back, through following a path towards redemption. (TV: The Lie of the Land, The Eaters of Light)

With her Zygon counterpart dead, (AUDIO: Narcissus) Petronella Osgood continued to work for UNIT and support Operation Double, refusing to disclose whether she was the human or the Zygon. The deceased Osgood's place was later taken by Bonnie; formerly the leader of the Zygon rebel group Truth or Consequences, she was convinced by the Doctor to back down from her attempt to break the ceasefire. (TV: The Zygon Invasion/The Zygon Inversion)