Spoilers follow.

About a week ago I said Doctor Who‘s Missy was another Moffat clone: a femme fatale adventuress totally indistinct on paper from River Song, Irene Adler and many of his other women. That post’s done well – embarrassingly well in fact, because this is the one where I eat my words.

Alright, not where I eat my words: my criticisms of her past appearances stand, as do my general comments on Steven Moffat, but having now seen ‘Death in Heaven’, Saturday’s follow-up to ‘Dark Water’, I’m won over. As of two days ago, Missy is in every way the Master… on top of which, this was NuWho’s best finale yet, one of Moffat’s best episodes and – just possibly – the one where he listened to viewers like me.

There’s so much to love about ‘Death in Heaven’ – for a start, its zingers.

• ‘Eighty-seven, I think. (OCD.)’
  ‘Ninety-one. (Queen of evil.)’
• ‘Cybermen don’t just blow themselves up for no good reason, dear. They’re not human.’
• ‘We don’t want Americans bobbing around the place. They’ll only start praying.’
• ‘We do have files on all our ex-Prime Ministers. She wasn’t even the worst.’
• ‘Your friends… they’re so moreish.’

The lion’s share went to Michelle Gomez, who finally got more to do than lurk and purr. Hers isn’t just a brilliant Master, it’s the incarnation I’ve wanted for years: one who just can’t stop killing, doing so at every chance instead of hovering round to explain the plot. (Farewell Osgood. Farewell Seb. Farewell nameless UNIT guards and ever-so-nearly Kate. Give Doctor Chang from last week our regards.) The Mistress, while not a chessmaster like Harold Saxon, is dangerously genre savvy, knowing that when the hero has a team of useful friends, they need to die as fast as possible. Moreover, Gomez’s Master is authentic. Watch her in action and you’ll see strains of the character that run back all the way to Roger Delgado: mind games, wry wit, obsession, psychopathy.

In her scenes with Peter Capaldi on UNIT’s plane or in the graveyard, the same relationship emerges that Delgado’s Master and the Third Doctor, Anthony Ainley and Five or John Simm and Ten enjoyed, brimming with everything from intimacy to resentment, disgust to total comprehension. You can argue Moffat wrote the psychotic-love married-couple routine he always returns to, but truthfully that’s always been the Doctor/Master dynamic – just watch Tennant and Simm on screen together, soulmates who mean more to each other than words like friend and enemy, love and hate could ever express. That kiss among the graves might have been heteronormative, but it also made decades of queer subtext into text. ‘I need you to know we’re not so different’, Missy pleads – ‘I need my friend back.’ And wasn’t that serial killer crush always there? What if it was never anything so facile, this episode dares to ask us, as a drumbeat on the brain? What if all along, the Master just wanted to impress the Doctor?

It’s almost like Moffat found a context where the relationship he always writes worked perfectly – except that what he did with Clara this time round was even better.

Series seven’s Clara was one more mystery in the shape of a girl. In series eight she became a character, brilliant and flawed in horrifically equal measure, hooked on adventure in the TARDIS till lies and consequences spiralled out of control. Her relationship with Twelve was that of two addicts enabling each other other, knowingly tolerating mutual deception – some of the darkest and most complex interplay of any TARDIS crew. When trailers told us Clara Oswald had never existed, my assumption was all this would be undone as Mary Morstan’s character was, another woman outed as a mere plot device. ‘Death in Heaven’ didn’t just avert that but subverted it, Clara bluffing the Cybermen to underline her real character arc.

Then that exit. Back in 2007 – was it really so long ago? – Martha Jones left the Doctor voluntarily, and Clara is only nuWho’s second companion to do so. Both endings are bittersweet but positive, Clara realising as Martha did that her relationship with the Doctor had grown unhealthy. (Next to Missy and Twelve, in fact, it’s arguable the episode pays tribute to two warped relationships.) That final shot of Clara in the street, walking toward an uncertain future, is hopeful next to Rose’s, Donna’s or especially Amy’s fate: graveyard notwithstanding, Ms Oswald wasn’t following her boyfriend into death.

Speaking of which: finally, some deaths that didn’t get reset. Not counting Missy’s obvious teleport apparent disintegration and Kate’s being cybercaught, we got more proper killings-off in one hour than in the six years since ‘The Stolen Earth’. Danny died either two or three times, but at any rate has now snuffed it – that faceplate-removal, by the way, was proper unadulterated horror – as have Chris Addison’s loveable AI and, yes, Osgood. Moffat still only develops female characters when necessary (one could almost see the realisation that before Osgood died, she had to matter), but at least some stronger lines got sent her way. Add in Kate Stewart, one of recent series’ better written women, and this was a pretty Bechdel-friendly episode.

All this achieved sans timey-wimey messing about, too. It’s a little like Moffat wrote his version of ‘Doomsday’ and it ended up miles better than the original. I’m reminded why, despite it all, I think he’s a good writer – and together with more fleshed out women, the permanent deaths make me think he’s finally changing his ways. If only he’d started a few episodes sooner.