Yes, Missy has claimed to regard the Doctor as a boyfriend, and, yes, she later threatens to shoot the Doctor in a ‘sexy’ jealous rage. But her kissing of him seems, if anything, to be a perverse act of power-staking, coming from one who is enjoying exploiting the upper hand.

Is such brazen sexual power play consistent with what we have known of the Master previously? Certainly.

Although we know very little of how Time Lord sexuality works, and how it may connect with gender or with that most changeable thing to Time Lords, biology, we do know that, where the Master is concerned, vanity, brutality and sadism feature prominently. A narcissist who has claimed always to dress for the occasion, when he took a wife, Lucy Saxon, his relationship with her was, like all his relationships, damaged, broken and abusive.

Is Missy lying then when she claims a romantic attachment to the Doctor (‘my boyfriend’)? Possibly. However, given that she doesn’t declare this to anyone other than the Half-Faced Man (and herself), there is a greater possibility, which is that, in her madness, she genuinely believes it to be true.

When Missy makes the Doctor feel her heart, she seems to glow with expectation of his response to her. ‘You felt it – surely you did,’ she observes later: the plural heartbeat, certainly, but something deeper than this too.

The Doctor, Missy says, maintains her heart, and, on one level, this is true: the two define each other. While the Doctor and the Master’s relationship has long been marked by enmity and rivalry, it has increasingly been marked by intimacy too.

It’s not so long ago, after all, that the Doctor cradled a dying Master in his arms, offering him a potential eternity of companionship, and, of course, the Master has previously mocked the Doctor for precisely this devoted fidelity, with the playground insult, ‘Are you asking me out on a date?’ It cannot be too extravagant a theory to suggest that this intimacy between the two – coming both from a shared history and from being the last of their species (in this universe at least) – must take a new shape now that one of them has changed gender.

If the Master is now going to use her new-found female fearlessness against the Doctor as a weapon, that’s potentially an interesting avenue: the Doctor undone by as crazy and badass a dame as ever he has met.

It will be a fine line to be drawn: to avoid the misogynistic cliché of stalker harridan and baffled male victim. But we have one advantage here: no one is likely to emasculate Capaldi’s grizzly bear Doctor. So long as the Master is now not going to be written like a deranged version of River Song – and that’s a big extrapolation to make from one kissing scene and one reference to boyfriends – then there is no cause for alarm.

Yet again, we are reminded that, in only seeing one episode of the finale so far, we are only seeing half the story. This time next week, all of this speculation may be redundant – although if it is all revealed to be a ‘teensy weensy fibette’ involving a Chameleon Arch, we’ll be disappointed. There is simply far too much story potential here to be thrown away so easily…

What was your reaction to the reveal? Let us know below…