7. Tying Up The Loose Ends
When the Master sensationally returned to our screens as Missy, we were kept largely in the dark as to what happened to Simm’s incarnation. He was last seen returning to the time locked Time War with Rassilon and his Gallifreyan entourage. Aside from a brief hint that the Doctor’s actions in The Day of the Doctor inadvertently saved the Master, exactly what triggered his regeneration into Missy remains unknown.
For years, the same was true of Paul McGann’s Eighth Doctor, until Moffat delighted fans with the surprise regeneration story in the 50th anniversary minisode Night of the Doctor. Such gaps are particular bugbears for the fan-base, as demonstrated by the various attempts in audio and book form to provide the story behind the Sixth Doctor’s botched TV regeneration.
John Simm confirmed the rumours of his return in a tweet that implied it’s all thanks to time travel. That much goes without saying, but it has nevertheless led some to wrongly assume that he will be plucked out of an earlier point in his timeline (ala The Five Doctors).
We are almost guaranteed to see a post The End of Time Master. He has been spotted with the blonde haired look that premiered in David Tennant’s finale, and Steven Moffat has previous in giving fans exactly what they want. Regeneration or no regeneration, we can expect to finally find out how the Master survived the Time War second time around.