Who is Missy?

1 November 2014

Today is the start of the season finale, and we will (I hope) find out the identity of the mysterious Missy.

There are many theories about this character:

• She is Susan.  Susan is the Doctor's granddaughter (or at least used to call him 'Grandfather') whereas Missy refers to him as 'my boyfriend'. So this can't be right as it's just too creepy and weird.

• She is a regenerated Rani.  Unlikely. The Doctor and the Master are supposedly the only Time Lords who survived the Time War. Unless the Nethersphere is in the same pocket universe that Gallifrey was saved to in Day of the Doctor.

• She is a regenerated Master.  Slightly more plausible.  We don't know exactly what happened to the Master at the end The End of Time - he disappeared into a white expanse.  This could have been some sort of alternative universe where he regenerated into Michelle Gomez. And 'Missy' could be short for 'Mistress', as in female version of 'Master'. Also the slightly bonkers aspect does seem a bit reminiscent of John Simm's Master, though perhaps too much so. 

• She is River Song. The arch way of referring to the Doctor would be more in keeping, but given that we saw her regenerate into her Alex Kingston appearance and then use up her remaining regenerations, and that this incarnation later (or earlier)  'died' in the Library, this seems unlikely.  Unless the Nethersphere is actually inside CAL, where River's pattern was saved.. Hang on, that needs thinking through...

• She is an entirely new character we have not encountered before. 

Given Steven Moffat's record, my theory is that he will make us wait another couple of seasons to find out.

Meanwhile, who exactly is Clara?