Survivors of the Flux certainly gave Doctor Who fans plenty to think about, with the penultimate chapter of series 13 revealing all sorts of crucial information and setting the scene for a pretty massive finale.


We learned the truth about the Flux, the Division, the history of UNIT (sort of), Joseph Williamson and much more – but with all that information, it was easy to get a little lost (a little like Williamson).

Luckily for you, we were taking notes – so here’s our attempt at answering the biggest post-episode questions.

What is the Flux?

Doctor Who: Flux

At least one big question got answered before next week's finale The Vanquishers, as we discovered who unleashed the Flux and why.

Back in Once, Upon Time, the Doctor (Jodie Whittaker) briefly encountered Tecteun (Barbara Flynn) – or "Awsok", as she was then credited – in the space between universes and was informed that the Flux "wasn’t an accident – it was made, it was placed… because of you."

More like this

Tecteun expands on this when the Doctor again finds herself transported against her will to Division headquarters, which we're told exists "outside one universe, on the cusp of many more."

In short, the Doctor departing Division, breaching the border between universes to enter our own, threatened to expose the existence of the Time Lord's secret police – as Tecteun puts it, "We let a virus into the experiment."

The Flux was created by Division as a means of destroying our universe and so obliterating any evidence of the Doctor / her shadowy past. It might seem like overkill – wiping out whole galaxies just to keep Division under wraps – but as Tecteun says, Division is "colossal, across space and time" and operates across a multiverse, so wouldn't think twice about zapping one universe among many.

Where is the Doctor from?

Basically, all we know for sure is that the Doctor isn’t originally from Gallifrey, with everything else up for grabs.

In this week’s episode, we’re reminded that Tecteun found the child who would become the Doctor on a distant world, standing beside a wormhole to another universe.

The implication is that the Doctor is actually from that second universe – but as the Doctor points out, that might just be an assumption. What if she was just visiting the wormhole from this universe, waiting to be collected when Tecteun scooped her up? Or what if she was from somewhere even further away, maybe one of the other universes Tecteun mentions?

Either way, the Doctor is offered the chance to explore that second universe and maybe, just maybe find her true home and people in the process. She doesn’t take Tecteun up on the offer before her stepmother is killed, but we doubt this storyline has been wrapped up just yet.

Why did the Lupari shield break?

Doctor Who

Thaddea Graham’s Bel was pulled into Earth’s orbit when Karvanista (Craige Els) and the Lupari fleet needed to fix a breach in their shield-wall, and her borrowed ship was the only one outstanding.

But… why did they need her anyway? In the episode, it seemed like one of the Lupari ships had drifted free, and with no response from the pilot Karvanista grimly pronounced them as "down". But the ship was still there – so why not remotely control the one a few metres away, rather than the one a few lightyears away?

We’re sure the show can make up some science-wiencey reason but for now, we’ll just have to accept the story needed Bel closer to Earth.

Where is Osgood?

Osgood (Ingrid Oliver) in Doctor Who

Kate Stewart (Jemma Redgrave) returns in Survivors of the Flux, facing off against Craig Parkinson's slippery Grand Serpent – though, as we know from 2019 episode Resolution, she wasn't successful in preventing "Prentis" from dismantling UNIT, leaving Earth alone to attack from a Sontaran fleet (and an opportunist Dalek, of course).

Traditionally, Kate has always come paired on-screen with UNIT's scientific advisor Osgood and while Ingrid Oliver's character doesn't appear here, she is mentioned when Kate contacts her friend to let her know she has to "go dark" to escape the Grand Serpent and – as we learn from the Next Time trailer – launch humanity's resistance against the Sontaran invasion.

So where is Osgood in all this? Will she too make a surprise comeback next week, back at Kate's side, or has she too gone into hiding? Fingers crossed the Grand Serpent and his pet snake haven't caught up with her...

What's going on with Joseph Williamson?

Doctor Who

Real-life historical figure Joseph Williamson (Steve Oram) has been drifting in-and-out of Flux, popping up at different points in time and space – and we finally learn how in Survivors of the Flux, with his excavation project part of a plan to protect Earth from "the destruction to come" and his underground tunnels containing "a dozen doorways [to] a dozen worlds".

Since Halloween, he explains, "all is flux" and "some of the doorways have changed" – which explains earlier scenes of a frustrated Williamson wandering about, lost, in the tunnels and in the temple of Atropos on the planet Time.

But there's still an awful lot that's not clear. Why did these doorways to other worlds suddenly spring up underground in Liverpool? How did Williamson know of their existence in the first place? How does he know about the approaching war for planet Earth? And what's beyond door number nine, which he describes as containing "endless death"?

What was the Grand Serpent's plan?

Doctor Who: The Grand Serpent (Craig Parkinson)
  1. Infiltrate UNIT
  2. Kill with psychic snakes
  3. ?
  4. Profit!

OK, to be fair there was a bit more to it than that. It seems like the Grand Serpent, having escaped the ruins of his civilisation (thanks, Flux!) decided to get back to scheming and deliver Earth on a platter to whichever alien nasties were still around in the universe.

He didn’t go back to 1958 and found UNIT, exactly – he just used time travel to insinuate himself within UNIT’s upper structure, dipping in and out of different time periods just enough to build up his position and take control. Kate Stewart speculated that from his perspective, it may have only taken a few hours or days to wind himself throughout UNIT’s history.

Then, firmly in power he was able to shut down UNIT and lower Earth’s remaining defences for his Sontaran paymasters. Simple! Ish.

What's with the scary house?

Flux's second chapter War of the Sontarans saw the Doctor appear to 'wake' in a black-and-white landscape, where she's greeted by a creepy-looking old house – and she experiences another vision of the dilapidated, strangely-proportioned building in Survivors of the Flux, this time accompanied by the 'whispers' of her lost memories contained within a Time Lord fob watch.

All of which suggests that the house is part of the Doctor's repressed memories of her time with the Division – but is it a real, physical structure she visited in the past or – like Irish police officer Brendan in series 12's Ascension of the Cybermen – does it represent something else, possibly something darker?

Following its first appearance, some fans have speculated that the building is the house of Lungbarrow – the Doctor's ancestral home which featured in a never-made TV story from the 1980s (which was later adapted into a novel), but is that too niche a reference? Maybe, maybe not – let's not forget that The Timeless Children featured the so-called "Morbius Doctors" as featured in 1976 story The Brain of Morbius, so we know that Chris Chibnall isn't opposed to throwing a deep-cut curveball into the mix...

What's happened to Claire?

Doctor Who

If you thought you’d seen the last of clairvoyant Claire, guess again – Annabel Scholey’s angel-infested psychic pops up again in the finale teaser trailer, albeit in some pretty dire straits.

"Yes, I am in episode six," Scholey told "I've lost track because the episodes have all kind of changed around but yes, I am in episode six.

"And it's nice, it was good to come back and kind of... I don't want to say 'finish her story' because I'm not even sure her story is finished, but it was good to come back and see those characters again.

"And you get a different journey with her in episode six. I can't really say more than that, I don't think."

In the Next Time trailer, it appears she’s hooked up to some sort of machine alongside her erstwhile ally Professor Jericho (Kevin McNally), suggesting that she may have been handed over to the Division after the events of Village of the Angels (Tecteun did get her angels’ memories in the end, after all). What the machine she’s hooked up to does is less clear, though based on this week’s cliffhanger we’re guessing it has something to do with Swarm’s (Sam Spruell) master plan.

Will the Doctor get her memories back?

The Doctor (Jodie Whittaker) in Doctor Who
BBC Studios/Ben Blackall

The Next Time trailer also appears to show Azure cracking open the Doctor’s memory watch (look, that’s what we’re calling it, it’s simpler), with the Doctor absorbed into its energy and symbols as her lost memories are returned – but could this be a red herring?

Somehow, it seems unlikely that showrunner Chris Chibnall would reintroduce a bit of mystery to the Doctor’s backstory only to have it all unveiled and returned to her that easily. It seems more likely to us that in the episode the Doctor will have to choose between gaining the lost memories she’s fought so hard to track down or saving the Earth (and/or her friends).

Knowing the Doctor, she’ll definitely pick the latter – and maybe finally accept that those years are lost to her, and what matters is what she does now.

Read more about Doctor Who:


Doctor Who continues on BBC One on Sundays. For more, check out our dedicated Sci-Fi page or our full TV Guide.