I genuinely love this story; it gives Dan a great introduction as well as the many side charactersthat are going to contribute throughout the season. I also love that it’s a Halloween episode. There are a few things introduced that I would like a better explanation of, though. All in all this gets a 4/5 from me.

For some people, a bad finale can ruin an entire series - I am not one of those people. This has been the case both within this show (I adore Season 8 despite Death in Heaven, and Season 14/15 despite their middling to bad finales), and with other shows (see: Lost, GoT). I think, sincerely, that Flux retrospectives are hurt by the fact that the final two parts frankly aren't very good.

While I understand that, to some, Flux is meant entirely in earnest as one six part story similar to old classic greats like the Talons of Weng-Chiang - but to me, it's simply a more compressed six episode arc. When I view it through that lens, I can't see The Halloween Apocalypse as anything but excellent. It's genuinely exciting, beautiful, well shot, hilarious, enthralling and horrifying all in equal measures. Seeing the Doctor bond so much with Yaz gives us the humanity and character led moments I feel were often lacking in previous seasons - and, while I admit my own potential bias for a companion so intrinsically linked with my home town, Dan exudes a certain realness and realistic core (while being incredibly funny) that allows me to connect to him in a way I'd so desperately wanted to connect to Graham or Ryan.

Karvanista - and, frankly, the Lupari as a whole, is a fantastic addition to the show too. It's something that feels so obviously great as a concept that it's a mystery that it hadn't been attempted before, and the effects work here (and Craige Els' acting) bring it entirely to life. I really, really hope we see more of him in Big Finish - especially with the Fugitive Doctor.

In just one episode that's frankly overstuffed with concepts, they all manage to be fleshed out in a way that provides them with sufficient narrative purpose and fulfilment in of themselves, while fully posessing you with the need to learn more about them all. It inserts that mystery into the show that the Cartmel Masterplan desired to do, with the drive of a showrunner who actually wants to see it all through. In the introduction to this review, I already alluded to the fact that I (and many others) do not think Flux sticks the landing - but I feel that is in no way the fault of this episode, and I feel the questions asked are still doors wide open for the Whoniverse to answer in equally enthralling ways in the future. I adore the Halloween Apocalypse, and I adore the idea of Flux - and, to me, the two are intangible, with The Halloween Apocalypse cramming the planting and germinating of the seed of that arc into just one fourty five minute episode.

I understand how it could be overwhelming and too fast-paced for some - but for me, it works. For me, it's a fast paced drama that matches the stakes with the vibe of the entire episode, landing the punch of a universe ending threat that the show ill-fatedly aims for so often. For that, I can never praise this episode enough.

This was, in retrospect, a decent start to the Flux, but given how much a waste of a time this six-part story is, The Halloween Apocalypse is ultimately kind of wasted for the fun atmosphere it kicks off with. It is also a bit annoying in how it just doesn't really follow up on anything meaningful from Series 12 here. Dan is fun, and that helps salvage an otherwise waste of our time a bit, but other than that it is really hard to value an episode I had fun with at first knowing that none of these plots points are going anywhere fun.

It's a shame too, because the Swarm has a cool start to him, I feel. It was a welcome moment of colour and energy that felt sorely missing from Jodie's first two years on the show, and at the time it came out I was excited to hopefully get something meaningful to get with Jodie before her time with the show was done. As it stands though, it is just a slightly memorable moment from a terrible time in Doctor Who history.