She has two hearts, right? The Doctor abandoned her, right? (Er, sort of) And Missy is short for Mistress, just like K9 used to call her. So I was well prepared. I had it all worked out. When Michelle Gomez purred in our hero’s ear “Well, I couldn’t really go on calling myself…” I was utterly convinced the next word would be… Romana.

Of course I was wrong. I always am when it comes to predicting Doctor Who twists. Other films and TV shows I’m quite good at. He’s a ghost. The murderer’s that guy no one suspects. She’s been there the whole time, and so on. But Doctor Who, the series I know better than anything else, stumps me every time.

I love it, of course. It’s part of the fun. But lots of other, more sensible people weren’t fooled. They’d guessed that Missy was a newly feminised Master long before the reveal. Many at the moment she introduced herself as “Missy”. I, on the other hand, had ruled out the possibility. Because, I thought, why would you recast the Master, when John Simm was so good in the role?

Any number of reasons, I suppose. Perhaps he wasn’t available to reprise his role. Perhaps he didn’t want to. Or perhaps it was simply time for a new person in the role. But if you miss Simm as I do, it helps that Gomez is so perfect in the role. She gives us a truly different version of the Master, (a character whose previous incarnations have tended to not vary so far from each other as the Doctor’s have) and not just because she’s a woman. We’ve never had a Master quite so batty. Or as she puts it, “Look at me. I’m bananas.”

(And despite myself, I feel I have to comment on the Master’s gender swap so here it is: big deal. if humans can change gender, I’ve always assumed that Time Lords could manage it with much less fuss and bother.)

There’s one Masterly aspect where Gomez’s Missy gets dead right and it’s the character’s habit of sudden, lethal violence. She never lets us forget that behind that Mary Poppins exterior (more filmic references), lies a psychopath to whom killing is an everyday habit. The cruellest moment is when she torments fangirl Osgood (Ingrid Oliver) before icing her – “I’m going to kill you in a minute” is one of Steven Moffat’s most chilling lines – but the most shocking is when she flings Kate Stewart (Gemma Redgrave) out of an aeroplane. With typical nonchalance, she moves quickly on to more killing. “Boys, blow up this plane and, I don’t know, Belgium, yeah?”

It’s that casual violence that makes the Master a compelling villain. For me, it’s a vital part of his/her character. Now this bit is where I commit Who heresy (Whoresy?), but this is why original Master Roger Delgado’s my least favourite. He rarely has those moments of utter ruthlessness that mark him as a truly bad guy. A rare example is when he throws a poor unfortunate scientist off the radio tower in Terror of the Autons, but Delgado is generally a safer, more avuncular Master than the rest. He might chop at a few necks and set a few elaborate traps, but he rarely resorts to immediate murder.

Anthony Ainley’s Master may have been a more theatrical Master than Delgado, but at least he had a few moments which showed off his shocking viciousness. Think of the moment in Survival when he sticks his young sidekick with a sharpened tusk. And there’s a great moment in the much underrated Planet of Fire when he’s threatening to incinerate some locals to force the Doctor to reveal the location of a vital TARDIS component. The Doctor pleads and says he doesn’t have the part. “I believe you,” says the Master, before he continues the burning anyway.

Eric Roberts’ gangster style Master in the TV movie got a similarly gruesome moment when he snapped Chang Lee’s neck without hesitation, not to mention when he strangled his host body’s wife in bed (thankfully off screen). Derek Jacobi was only seconds into his brief tenure when he electrocuted Chantho with one sparking cable. John Simm’s Master gassed a room full of politicians and ate two homeless men. Sudden, unexpected violence is the Master’s true calling card, far more than turning people into action figures.

What Simm brought to the role, and what Gomez has picked up on, is a kind of dangerous wackiness. Their Masters are clearly loopy, and in Simm’s case, driven insane by that infernal drumming. It’s as if modern day Who needs to rationalise the Master’s villainy as a byproduct of mental instability. It’s not enough for him/her to be evil. He/she’s unhinged, and that explains why he’s/she’s evil.

The other thing Gomez continues with is the Master’s close association with sex. One of the first things she does when meeting Peter Capaldi’s fierce and feisty Doctor is to snog him.

In Old Who, the Master has always been sexualised in a way the Doctor was not. And in New Who there’s a real difference apparent in presenting them both as sexual creatures. It can be summarised like this: the Doctor gets romanced, the Master gets laid. John Simm’s Master was clearly a sexual being. He married an Earth woman, and they canoodled like teenagers. In The Last of the Time Lords he emerges presumably from bed, hair disheveled and in a satin night gown, like he’s been interrupted. He even suggests a threesome at one stage, and Lucy Saxon’s battered and dazed appearance casts the dark shadow of violence over their relationship.

But even in Old Who, the Master was about sex and violence, both activities which set him apart from his own race, the passive and passionless Time Lords. Delgado, as we saw in The Time Monster seduced a married woman. Eric Roberts’ Master was born in a marital bed. Even the staid Ainley version chose to assume the body of a man in love with his new bride. It seems that between the Doctor and the Master, it’s the latter who ‘owns’ sex, and as a result, the series positions sex with corruption and crime.

But let’s get to the big question: now that she’s a woman, will the Doctor and the Master get it on? Well, let’s not be heteronormative about this, it was always a possibility (although let’s stick with a Tennant/Simm pairing rather than think about any of the other possible Doctor/Master hook ups. Ooops, too late, you have haven’t you?) But now, they could actually have kids!

My bet’s on a girl first time round. They’ll call her Romana.  (Or maybe Maisie?) That’s my theory and I’m sticking with it! Because having got my Who twists wrong so many times, my luck’s got to change eventually.

ADVENTURES IN SUBTITLING: Gallifrey is spelt Galyfrey at one stage, which is quite fetching actually. Perhaps if they have a boy.

LINK TO: The Gunfighters. Get this: they both feature Tombstones. That made me smile.

NEXT TIME: We’re off to infiltrate The Moonbase. Clever, clever, clever.