What is Missy’s Heaven, we asked? Another planet? A TARDIS? A fantasy world peopled by consciousnesses saved to a central computer? A sort of posh green room for Doctor Who’s old extras?

As to who she was, it took roughly eight seconds after Deep Breath’s end credits rolled for comments sections the world over to belch out a familiar cloud of “She’s the Rani/the Master/the woman in the shop/Tasha Lem’s big sister/a manifestation of the Doctor’s guilt/your mum.” Because that’s how this game works. Between now and the series eight finale, it’s our job to gobble up every one of Missy’s new titbits and appearances, and use them to fuel an ongoing argument that will only conclude come the show’s series finale revelation – if then.

Considering we’re now on the fourth round of Steven Moffat’s ‘Mystery Woman’ game (or fifth, if you count Amy Pond’s universe crack-based amnesia, or sixth if you count The Time Of The Doctor’s Tasha Lem), we must have picked up a few tricks along the way to give us a competitive advantage. What then, did we learn from the mystery appearances of River Song, Madame Kovarian and Clara Oswin, that may help us solve the mystery of Steven Moffat’s latest enigmatic Who addition?

Names are important

It was in A Good Man Goes To War, the mid-series six finale, that River Song’s identity was finally revealed three years after we were first introduced to the Professor in series four’s The Silence In The Library. The revelation that River Song was in fact Melody Pond finally made sense of Idris’ message from The Doctor’s Wife that “the only water in the forest is the river”, which turned out to be a linguistic riddle. The language of the Gamma Forests is a tricky one to translate, it turns out. Not only does the word ‘Doctor’ mean ‘Great Warrior’ in honour of his knibs, but the only word the Gamma Forest has for a body of water is ‘River’, hence the name Melody Pond being transposed into that of River Song. It’s simple when you know the answer.

We could surmise then, as many have, that Missy’s name will be a clue to her identity. We would be the millionth to point out at this stage that it’s a shortened form of Mistress, which has the undeniable ring of the Master to it. However…

Except when they’re not