‘We’re stuck in a time loop with killer robots.’ It opens, like that other New Years Eve episode the TV Movie, with an old-style club song: appropriate for an episode set in a temporal orbit. What follows is like Heaven Sent reimagined for a bleary-eyed audience blinking through the excesses of the night before, with a simple plot (the TARDIS has caused a time loop while regenerating post-Flux, so the Doctor and friends get multiple chances to avoid extermination by vengeful Dalek survivors of the Flux).

If Revolution of the Daleks was an RTD Christmas Invasion (at New Year), this is more like one of Moffat’s timey-wimey rom-coms. It benefits from a genuine guest star performance by Aisling Bea, with a beautifully balanced mix of exasperation, desperation and consternation. She brings this to life in the way Catherine Tate enlivened The Runaway Bride, and Sarah becomes the first of Chibnall’s one-shots I’d have loved to see become a regular. And, credit where it’s due, this isn’t entirely due to Bea’s performance but also Chibnall’s neat glimpses of a life largely kept off screen (but glimpsed through her mother’s pre-bongs FaceTime), but nevertheless vivid and real – with a key role in the climax.

It’s also easily the funniest thing Chibnall has ever written. Nick is a very Moffaty character, socially awkward, hung up on his ex-girlfriends like he’s wandered in from Coupling. His storage unit marked up with the details of his exes leads to that brilliant moment of Sarah and Yaz exchanging worried glances: ‘They’re alive still, aren’t they?’ then ‘Just throw stuff away!’ (Nick also means Chibnall can get Nick Briggs to Dalek voice, ‘I am not Nick’, which is the kind of harmless in-joke that amuses me). The Doctor and Dan get some funny bits too (the Doctor’s annoyance at Nick’s rubbish escape plan; Dan’s disgruntlement at arriving in Manchester, and his distracting a lone Dalek in reception).

What I particularly liked about the episode is, the characters all retain their memories from the previous loop, Therefore, Sarah and Nick’s relationship can start to develop across eight minutes, as she sees beyond the annoying man who never throws anything away to the caring, brave person underneath. The problem is – the Daleks are also learning each time and becoming increasingly dangerous. Combined with the loop shortening a minute each go there’s a sense of jeopardy and urgency that side-steps some of the pitfalls of this kind of story. Could it have been told as well in 45 minutes? Almost certainly, but I wasn’t checking my watch during the extra 15.

I’m less sold on Yaz’s crush on the Doctor – not because it hasn’t been trailed (she chose to stay when Ryan and Graham left and was clearly moved by the Doctor’s hologram message in Flux), but because we already knew by this point that the show was running out of time to do much with it. Plus, the Doctor’s rather offhand treatment of Yaz skirts close to the 10^th Doctor’s behaviour towards Martha. So, I have quibbles, but I can find quibbles about any Doctor Who episode. This swaps location-hopping, apocalyptic epics for small-scale, personal-stakes fun, becoming the best New Year special of all, and the jewel in the crown of Chibnall’s run.

Next Time: Legend of the Sea Devils