The Winter King ending explained: Writer on Aelle and Isle of the Dead

Nimue had been banished there following accusations of murder by the ambitious priest Sansum (Andrew Gower), who sought to set up a church on the grounds of Avalon, despite it being sacred to the pagans.

Ever loyal to his first love, Derfel staged a daring rescue – but can they escape the nightmarish prison unscathed?

Read on for a full breakdown of the season 1 ending, including commentary from screenwriter Kate Brooke, speaking to ITVX's official The Winter King podcast.

The Winter King ending explained: Who is Aelle?

After a colossal blowout with his protege Derfel in the penultimate episode, Arthur continues with his plan to forge a temporary peace with Saxon warlord Aelle (Craig Parkinson), which will buy them crucial time in the struggle against Gorfydd (Aneirin Hughes).

In Derfel's absence, Guinevere (Jordan Alexandra) instead accompanies her husband to Aelle's territory, both to translate with her understanding of the Saxon language and to offer political counsel – which proves to be vital.

Indeed, against Arthur's initial wishes, Guinevere adds to the truce agreement instructions on how to capture Ratae, realising that weapons and materials alone won't satisfy Aelle. Land is what he and his people truly desire.

After being teased earlier in the season, Aelle is the latest foe added to Arthur's long list of worries, but The Winter King co-writer Kate Brooke explained she didn't want him to be a cut-and-dried villain like Gundleus (Simon Merrells) or Gorfydd.

Speaking to ITVX's official The Winter King podcast, she said: "I think he's interesting, because we talked about him as being actually quite similar to Arthur. There's a civilised side to Aelle, which is surprising... his perspective is just a different one.

"It's not like he's a bad guy, he's just there; he's conquering, he's got people to look after, his guys are going to die unless they conquer more land. And I hope that he feels like a surprise in episode 10. I wanted him to not be a toxic villain."

Brooke continued: "The way that we did that was, rather than doing a physical confrontation – a big sword fight – the thing that Arthur and Aelle do is talk, and you feel like Arthur's met his match in terms of a thinker and a thoughtful leader."

If The Winter King is renewed for season 2, this is a character viewers can expect to see more from.

What are the "monsters" on the Isle of the Dead?

Once a fragile peace is achieved between Dumnonia and the Saxon invaders, Arthur endeavours to catch up to Derfel, who has bravely infiltrated the terrifying Isle of the Dead in search for Nimue.

He discovers her deep inside the isle's cave system, although initially she refuses to believe that he's real, having suffered to the point of delirium. Fortunately, he is able to convince her, pointing out the scar that bound them together much earlier.

However, before they can escape from the isle, they are backed into a corner by a horde of sinister figures – are they zombies? Vampires? Demons? Actually, none of the above.

Brooke detailed on The Winter King podcast how these are really just ordinary people, who have been turned "feral" by extreme mistreatment from Uther's regime.

"We talked about, 'How do you make the Isle of the Dead frightening enough? And what is 'the monster'?' And we decided that this is really just about people being so hungry that they become monstrous," she explained.

"We really talked a lot about the kind of tribal nature of the Isle of the Dead – some people have gone into one area, and then these people have gone to the dark side."

Fortunately, Arthur comes to the rescue of Derfel and Nimue, plunging his sword into a bricked up passageway, in an act that mirrors the traditional pulling off Excalibur from stone.

The warlord is reeling from the revelation that his late father, Uther (Eddie Marsan), specifically requested the treatment of the prisoners to be so barbaric.

"I wanted to return to Uther in episode 10 and get a sense of Uther's influence – and it is shocking that we hear that he actually condoned this," added Brooke. "It's a moment where Arthur steps out of his father's shadow.

"He's obviously horrified by what he sees, and he has a humanity to understand that all of these people are humans and have just been treated absolutely atrociously. So that all tied in very nicely."

As a result of the terrible suffering he's witnessed, Arthur drops the Pendragon name in a bid to distinguish himself from his father, before making amends with Derfel and Nimue.

Why does The Winter King end here?

Readers of The Winter King book series by Bernard Cornwell – titled The Warlord Chronicles – will be aware that season 1 takes us only about two-thirds of the way through the first entry.

It is hoped that all three books will be fully adapted across five seasons of the series, although ITV is yet to announce whether the show has been renewed.

Brooke discussed on the official The Winter King podcast how she and co-writer Ed Whitmore came to the decision to base their finale on the Isle of the Dead.

"In episode 10, there are two story strands which we deliver," she began. "One is the Isle of the Dead and one is Arthur making a deal with the Saxons. And we felt that that gave us a good, epic out for all three of our triumvirate of key characters.

"The challenge with the book is often they're in different places... because the book is written, obviously, entirely from Derfel's POV. We love the fact that, actually, in the book, in the Isle of the Dead, all three of them are there."

Brooke added: "And we felt very strongly that, after all the conflicts between, for example, Nimue and Arthur... we really wanted to end up in a place that they were together.

"That their journeys have all brought them into a space where they are literally all physically together, but also they've all helped each other [and] learned from each other. That was really why the Isle of the Dead felt like the right place."

The Winter King is available to stream on ITVX. Check out more of our Drama coverage or visit our TV Guide and Streaming Guide to find out what's on.

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