Where do we even start with this episode? As we pondered in our review of last week’s penultimate instalment, perhaps there were too many hanging threads left to tie up in just a single episode. The Vanquishers – the final chapter of Doctor Who: Flux – is an entertaining enough finale, though it doesn’t exactly hold up to much scrutiny in the long run…

One positive about Chris Chibnall‘s writing is that he’s certainly ambitious. Flux has thrown in a lot of high concept ideas over the course of its 6-hour runtime and for the most part they’ve complemented one another well enough so as to ensure everything feels part of a whole. But there’s no doubt that The Vanquishers feels cluttered as it trips over itself to tie everything together and wrap it all up satisfactorily. Some aspects get short thrift, others are just about handled well, and a few just fall by the wayside forgotten.

Swarm and Azure are the main casualties of this overabundance of plot. These two excellent villains are pretty much dispatched with zero fanfare, their masterplan left as ambiguous and mysterious as it was when they first appeared in Chapter One. There’s some talk about torturing the Doctor by destroying the universe with the flux over and over again, but it’s only mentioned briefly in passing and neither the two villains or their plan are really the main focus of this episode. Instead, we get the Sontarans trying to kill the Daleks and the Cybermen, an out of nowhere plot development that feels out of place in this already cluttered finale.

It’s a strange decision on Chibnall’s part that the Sontarans dominate proceedings as much as they do here, especially as they’ve never been the main threat of the series until now. They were pretty much defeated at the end of War of the Sontarans, so their sudden reappearance here is a major step-back in terms of narrative and feels rather like the series retreating desperately for familiar territory. Craig Parkinson‘s Grand Serpent is a solid enough villain and his scenes opposite the Doctor are electric, but his character’s presence feels like just one villain too many in the grand scheme of everything else going on.

There are moments here amidst the chaos that do work though. The way the Doctor utilises one of the ominous Passengers to absorb and halt the flux is one of those great ‘hiding in plain sight’ resolutions that we didn’t see coming, and whilst it may be rushed, it just about works and satisfies as a wrap up for the unstoppable flux threat. The Doctor playing off against two other versions of herself is a nice comic touch which also provides a handy escape for her when going up against the Grand Serpent (even if the editing is all over the place and makes keeping up with each version a trial) and the death of Jericho (Kevin McNally) is beautifully handled, playing out with the right amount of pathos.

Another tick in The Vanquisher‘s pros column is the amazing visual effects work, which lends proceedings a real sense of epic scale that’s been lacking in previous Chibnall-era finales. The focus on action and spectacle is ten times that compared to the talky info-dump finale of Series 12 and Series 11’s rather underwhelming outing, and feels like he finally has a firm grasp on upping the stake appropriately this time out. It’s a shame a lot of the visuals and major action beats are let down by some sloppy editing, but nonetheless, it’s a gorgeous looking piece of work, especially in the big destructive moments. Safe to say, the visual effects team are on explosive form here.

Also on explosive form here is the show’s MVP Jodie Whittaker, who has an utter delight to watch this series, and especially here when she’s either playing off against Swarm (Sam Spruell) and Azure (Rochenda Sandall), Craig Parkinson‘s aforementioned Grand Serpent, Karvanista (Craige Els) or even herself (thrice). A dynamite performance that is loud, energetic and funny, yet poignant and understated in the moments that count, Whittaker is totally absorbing throughout. It’s episodes like this that remind us what a loss it will be for the show when she leaves in 2022, but we can take solace in the fact that she’s getting plenty of opportunity to show-off her range and build on the character this far in to her tenure.

Sadly, other regulars John Bishop and Mandip Gill are rather sidelined, which is a shame, especially as a lot of the other guest characters also suffer from the same issue. Bel, Vinder, Kate Stewart and Claire all feel tertiary to proceedings, constantly vying for space in overcrowded scenes, and no one feels well served by the drama aside from the Doctor, Karvanista and Jericho. There’s a hint of some drama with Yaz and the Doctor in the closing scenes, but it’s dust in a sandstorm.

Ultimately, The Vanquishers doesn’t deliver what it promises, but it at least entertains enough so as to not leave audiences completely disillusioned. There are a lot of questions left hanging and it remains to be seen if every single one will be answered before the end of Whittaker’s tenure. Is the universe still decimated as a result of the flux event from Chapter One? Is the TARDIS still sick, and if so, why? What about the Doctor’s forgotten memories – are we done with that or not? It’s infuriating but understandable that everything hasn’t been explained yet, especially with only three specials to come, but there is a nagging feeling that priorities laid elsewhere here and maybe they shouldn’t have. Less Sontarans, less secondary characters and a tighter focus on the bigger picture would certainly have made The Vanquishers a worthy final episode for sure.

As it stands though, The Vanquishers will most definitely disappoint most viewers on further reflection, but there are many elements within to satisfy and thrill in the moment. On the whole, Flux has been an ambitious step in the right direction for modern Doctor Who and whilst it may be too cluttered and unwieldy in its own right, it certainly shows ambition and succeeds in shaking Doctor Who‘s format out of the rut of the last couple of years.

Doctor Who returns to BBC One on New Year’s Day. Be sure to check out our other Flux reviews in our Doctor Who Series 13 series blog.