Well actually, there's two. Yep, cheeky me.
First of all, I firmly believe that Missy is who she says she is. She is the artist formerly known as The Master.
In the body of The Rani. Just a minute, hear me out.
In both the preview trailers for Dark Water and Death in Heaven, there is a snapshot of Missy suddenly waking up in a state of shock. Already wearing her nice new feminine guise. To me, that looks like a possession rather than a regeneration.
The last time we saw The Master, his body was dying. He was teetering on the edge of destruction and one can only theorise - until this Saturday of course - what happened after his battle with Rassilon. Presumably he either defeated him or escaped before too much damage was done.
The Rani, at least I would like to think, would've had some part to play in the events of the Time War. Okay, so Moffat and others have dismissed her as being not really 'iconic' enough to return to the fold these days, but I would disagree. Sure, the two stories she featured in were not exactly...well, they were clangers, let's face it. But the character itself wasn't. She was tipped by many in fandom to be Missy, so she can't be that irrelevant.
Perhaps she had a part to play in Missy's return. She may have had many more regenerations left in her cycle. Thus, The Master either tracked her down and hypnotised her into swapping bodies, or he discovered her recently deceased and possessed her in that fashion.
That way, several ideas are combined and The Rani finally makes a return of sorts, without actually 'being' The Rani, if that makes sense.
Missy somehow sneaks aboard one of The 13 Doctor's TARDISES during the events of Day of Doctor after Gallifrey is saved and takes a pit stop some time between The Snowmen and Bells of St. John where we meet our first couple of Claras, and the Nethersphere Masterplan begins...
My second theory is similar to the first, but doesn't include The Rani and is much more simple and less fan wankery.
Missy is The Master's final, 'Valeyard' form, if you will. She has regenerated several times since Simm's incarnation off-screen, and fully aware of The Doctor's newly awarded regeneration cycle is hell (or heaven) bent on stealing his body. She escaped through the cracks in Time plotted throughout 11's tenure.
And now I'm tired. :-P
First of all, I firmly believe that Missy is who she says she is. She is the artist formerly known as The Master.
In the body of The Rani. Just a minute, hear me out.

In both the preview trailers for Dark Water and Death in Heaven, there is a snapshot of Missy suddenly waking up in a state of shock. Already wearing her nice new feminine guise. To me, that looks like a possession rather than a regeneration.
The last time we saw The Master, his body was dying. He was teetering on the edge of destruction and one can only theorise - until this Saturday of course - what happened after his battle with Rassilon. Presumably he either defeated him or escaped before too much damage was done.
The Rani, at least I would like to think, would've had some part to play in the events of the Time War. Okay, so Moffat and others have dismissed her as being not really 'iconic' enough to return to the fold these days, but I would disagree. Sure, the two stories she featured in were not exactly...well, they were clangers, let's face it. But the character itself wasn't. She was tipped by many in fandom to be Missy, so she can't be that irrelevant.
Perhaps she had a part to play in Missy's return. She may have had many more regenerations left in her cycle. Thus, The Master either tracked her down and hypnotised her into swapping bodies, or he discovered her recently deceased and possessed her in that fashion.
That way, several ideas are combined and The Rani finally makes a return of sorts, without actually 'being' The Rani, if that makes sense.
Missy somehow sneaks aboard one of The 13 Doctor's TARDISES during the events of Day of Doctor after Gallifrey is saved and takes a pit stop some time between The Snowmen and Bells of St. John where we meet our first couple of Claras, and the Nethersphere Masterplan begins...
My second theory is similar to the first, but doesn't include The Rani and is much more simple and less fan wankery.
Missy is The Master's final, 'Valeyard' form, if you will. She has regenerated several times since Simm's incarnation off-screen, and fully aware of The Doctor's newly awarded regeneration cycle is hell (or heaven) bent on stealing his body. She escaped through the cracks in Time plotted throughout 11's tenure.
And now I'm tired. :-P