John Simm’s Master was last seen in 2010’s ‘The End of Time’, attacking Rassilon as he disappeared along with the High Council to Gallifrey before the planet was removed from the known universe.
Gallifrey was last seen in 2013’s 50th anniversary special, when the Tenth Doctor, Eleventh Doctor and War Doctor froze the planet in time within a parallel pocket universe.
The Master then returned in the regenerated form of Missy, played by Michelle Gomez, in last year’s ‘Deep Breath’.
However, it has not yet been explained how and when the Master managed to get away from Gallifrey.
In this shot from ‘The Day of the Doctor’, a female hand appears to emerge from the ‘Gallifrey Falls No More’ painting.
Could this be how Missy escaped ?
It could be – and probably is – Clara, but it’s a very strange angle and certainly looks as if it’s not attached to Jenna Coleman.
Michelle Gomez will return as Missy in Season 9’s two-part opening story next month, so perhaps we’ll find out then.