Let’s start with the end. When Eccleston quit after one year, Russell briefly wondered whether it would be possible to pull off a surprise regeneration. How amazing for a new generation of kids who had never seen the show before to see the Doctor change his face before their eyes, without knowing such a thing was even possible. Sadly, it was not to be – Eccleston’s departure and the identity of his replacement was known weeks before. But Ncuti Gatwa’s era is highly unusual, having been planned, written and produced pretty much as a single two-year story. That isn’t to say that everything for The Reality War had been shot by the time The Church on Ruby Road went out, but there was a structure and a plan in place in a way which we’ve really never seen before. Eight episode seasons are good for something it seems.

And with the Disney deal expiring following the upcoming The War Between The Land and The Sea, at present nobody knows what the future of Doctor Who looks like, but it seems the Gatwa was told that a two-year deal was in place and responded “Sure, I’ll do two years.” So this moment was always coming, even though nobody expected it, and I certainly didn’t expect Billie Fucking Piper to be staring back at me as the episode ended. As many have spotted, she is credited only as “And introducing Billie Piper” so who knows what further fuckery is afoot, but we’ll have to wait for answers.

The rest of the episode falls into two halves, very much in the way that The Giggle did, with the villains despatched somewhere around the 35 minute mark, almost exactly the midpoint of the episode. But while I criticised The Giggle for building to a climax and then hanging around for 15 or so minutes of less thrilling story admin, I didn’t have the same problem here. Firstly, those first 15 minutes are absolutely bonkers brilliance. The Time Hotel is a wonderful idea to revisit, the Doctor shedding the John Smith costume and returning to his pinstriped kilt is a real punch-the-air-moment, we get glimpses of Troughton and Pertwee and Daleks, and we get a truly horrifying CGI Omega (which alas Gatwa manages to pronounce in just about every way except the one we’re used to).

I also think the structure works better than last year’s Empire of Death. Sure, Omega doesn’t get to do much except munch on Rani and then be banished, but the problem with ending the world is that you have to un-end the world again to send us out happy. It might feel less exciting to have life as we know it merely threatened and not ended, but I prefer crisis-averted-but-at-what-cost to the-worst-has-happened-and-now-we-have-to-reverse-it. Your mileage might vary, but I feel the storytelling scales are balanced better this way.

The pals are all there of course, and most of them have something to do – Rose barely enough and the Vlinkx still absolutely nothing whatsoever. But Mel gives good value and Kate is always a welcome presence. Even the long exposition scene between the Doctor and the Rani is good fun, in no small part thanks to Archie Panjabi’s lip-curling relish at playing this fabulous part, in a costume which is part dominatrix, part John Nathan-Turner and part Martha Jones. And I absolutely hooted with laughter at Anita Dobson’s “Two Ranis” exit line.

Millie Gibson, undoubted MVP of the last series, once again shows her class here. She’s amazing, whether when fighting to overthrow the Bone Palace from below, standing alongside the Doctor in UNIT HQ, but especially when she’s desperately trying to convince him that the fight isn’t over yet. The moment of Varada and Ncuti passing baby Poppy’s orange jacket back-and-forth as it shrinks and finally vanishes is tremendously effective, setting up the final problem not with a crash and a bang but with a creeping sense of unease.

So here are the two reasons why I think the second half of this episode was just as thrilling as the first half. Reason one: we haven’t had the regeneration yet. We’re promised it 50 minutes in, but it doesn’t happen until the very end. The Giggle blew its load after Gatwa’s first appearance, and everything after that feels slightly anti-climactic as a result.

Secondly – and this may not have been entirely deliberate as rumours abound of last-minute re-shoots – but the presence of Susan last week does an awful lot to very subtly but very definitely raise the stakes on baby Poppy. When writing my book about Star Trek, one of the tropes I identified was the cover-of-a-comic-book teaser. The purpose of the cover of a comic book is to get you to buy the comic (just as the purpose of a teaser is to get you to stay on this channel and watch the rest of the episode). So it’s very tempting to start with something really eye-catching, which may or may not be paid off in the way you expect. The cover of the comic book shows Clark Kent pulling open his shirt in front of Lois Lane. When you read the story, it turns out she’s been temporarily blinded and couldn’t see the costume under his clothes. That kind of thing.

So it doesn’t matter how many times Varada and Ncuti tell us that Poppy is their child, we know that the Doctor can’t have a kid with a human woman, and we know it’s all going to be reset by the end of the episode – once again, the storytelling scales are out of balance. But half a mo. There’s Susan. And we’ve been reminded that the Doctor once travelled with a granddaughter. And you can’t have a grandchild without first having a child. So… maybe? Just maybe, Poppy is here to stay after all?

She is and she isn’t. Fifteeen pours that regeneration energy into the TARDIS and brings Poppy back. But she’s not his daughter. She’s Belinda’s. And that does make sense – more sense ultimately than her being Susan’s mum – but these two dangling threads kept me going all the way to the end of the episode. And gawd, I haven’t even mentioned Jodie Whittaker yet, here to give a barely-needed pep talk to our hero before he risks everything for the sake of one little life. Whittaker clearly relishes getting some RTD dialogue to say, but alas we slip back into Chris Chibnall just-say-exactly-what’s-on-our-mind mode right at the end when she says “I should say that to Yaz.”

But that is honestly my biggest complaint with this episode, and sure a lot of the first half is a hyperkinetic whirl, and it takes a long time after that to come into land – but all of that felt purposeful, deliberate and carefully judged. The Doctor’s victory is incomplete, hard-won, and the product of desperate last-minute improvisation and reliance on his friends, not simply waving a thing and spouting some gibberish. Conrad is undone not by violence but by kindness. And our hero gave everything he had for one single life. I don’t approve of Doctors only doing two years, but Ncuti has been magnificent, and I can’t wait to see what happens next. Bravo.

5 out of 5 stars