Where do we find our core cast at the beginning of this special?

This special sees the TARDIS crew landing in a coastal village in China, on the trail of the mystery of the treasure of the Flor de la Mar, which the Doctor has been meaning to find out about for a long time. When they get there, they discover some very strange events and a terrible evil being unleashed in this village!

What was your inspiration for this episode and how did you come to work together with Ella Road on this script?

We had been intending to do a piratey story during Flux and we didn't manage to make it work for all sorts of reasons. So when it came to thinking about the final specials that was one of things I really wanted to revisit, to do a big, thrilling Bank Holiday romp of an adventure for Jodie's penultimate story, featuring a warrior pirate queen. Ella (Road) then came to us with the idea of Madam Ching - this incredible character from history - and it all knitted together thanks to her.

Can you tell us a bit about the process of bringing the new guest actors on board?

We are always really lucky on Doctor Who as we have one of the best Casting Directors in the business in Andy Pryor. Andy’s great at keeping tabs on everyone and also uncovering great new, young talent as well. So when we were thinking about the story, I talked to him and gave him a heads up on the characters that we were thinking of. Usually the process is that Andy will put together a list, people who will tape and we'll look at load of people so that's how it went on this and we saw some amazing people.

Crystal (Yu) just absolutely shone out, and then we also Marlowe Chan-Reeves who plays Ying-Ki, I think this is his first television job and he's an absolute star of the future. It's something that happens all the time on Doctor Who, down to the genius of Andy Pryor and his team – they’re the unsung heroes of the series since 2005. They have cast every episode and this litany of incredible guest actors is absolutely down to them and their brilliance. The show owes that team a huge debt of gratitude.

Why did you decide to bring back the Sea Devils? Was it always planned? How did you go about bringing that vision to life with your team?

We didn't start with Sea Devils at all, but the great thing about Doctor Who’s history is sometimes you can pull on all of that history and go, “Oh wait okay, the perfect monster has already been created, and is already in there!” So you can spend a long time thinking about creating or making a bespoke monster for this story, but actually, we thought, “If you add the Sea Devils in, this becomes really exciting” – they bring an extra layer of story, an extra layer of thrills and an extra layer of meaning for the fans. And so it wasn't always in there but when we put them in and tried them out it really worked.

Then the question is whether you do a big redesign, as we did with the Silurians when I was working for Steven Moffat on Matt Smith’s first season. They were created by the same writer, Malcom Hulke, and are sort of cousin monsters! With the Sea Devils, it felt like there were ways that we could fit that original, brilliant and recognisable design into this story and have a bit of fun with it, pirate them up a little bit while also doing little bits of updating and augmenting – but fundamentally retaining the incredible design by John Friedlander.

So they’re very much his creation, and updated by Robert Allsopp and Ray Holman, our costume and monster designers. Then we were really lucky in that we had Craige Els, who played Karvanista in Flux, as the Chief Sea Devil. He’s a magnificent actor who is now beneath another mask– we still haven’t seen his real face in the main show! He does a brilliant performance and we knew we needed a really great actor - a great voice actor and a physical actor as well. What he brings is just gorgeous, as always.

What was added in after filming? They seem very true to the prosthetic that was created by Robert Allsopp.

It’s just things like expression, blinking of the eyes, they do a bit of snarling - just tiny little things to make sure that things come alive but they’re very much the monsters as you saw them previously.

There seems to be great anticipation about their return?

It’s the lovely thing you can do occasionally - there aren’t millions of Doctor Who monsters that you can bring back. But there’s a lovely affection for the Sea Devils, and they haven’t been used in the modern era. Also probably my earliest memory of Doctor Who and probably my earliest memories of being alive almost, is seeing them on the TV, so it was a nice thing to do in the penultimate story we were doing.

How does the relationship between Yaz and the Doctor develop further in this episode?

Dan has cottoned onto the dynamic between the Doctor and Yaz and from a distance, observed what they haven't been admitting to themselves. I think really, in Eve of the Daleks, both Yaz and the Doctor have hinted that they have feelings that they are suppressing and keeping quiet about. So there are some conversations that need to be had and you'll see those conversations developing and taking place in Legend of the Sea Devils. The Doctor and Yaz have something to talk about!

Would you say this is more of a standalone episode?

Yes, it’s a big standalone bank holiday action romp for all the family! A rollicking, swashbuckling adventure for the Doctor, Dan and Yaz with big monsters, big pirate ships, the sword fights, lots of fun, loads of action, lots of lovely jokes and a great, fun tone before we go into the big epic battle for survival with Jodie's final episode.

This episode was of course filmed during strict COVID restrictions. What were some of the bigger challenges that you faced in making it happen?

It was a huge ask, and I didn't know whether we could do it after the production team had pulled out all the stops for Flux. We knew it was a big deal to be able to transport the show back in time, around the world, onto ships and onto the seas. It’s just a testament to the whole production team from first to last - from pre-production to post production.

Daf Shurmer, our Production Designer, is an absolute legend himself and he did something that I think should have been impossible - and I think was impossible - and he achieved it. He's just given us such scale with so many great sets that look amazing.

Haolu Wang, our brilliant director, and Mark Waters our Director of Photography, have shot it wonderfully with energy and love and fun, and the cast all got into that. And DNEG who do all our CG and visual effects have just delivered something really special. We've got sea monsters, we've got pirate ships, we've got the oceans, and we’re in an ancient coastal village!

As with every episode of Doctor Who, is it was a massive team effort. Everybody involved in the COVID procedures on Doctor Who whether it was testing everybody or sorting out the bubbles - we never had a day shut down due to COVID, it involved incredible work by the whole team. And the fact that I think Jodie Whittaker did not go out for almost a year, while she was working on her final series -she set such a great and responsible example, and put the show first.

For anyone who is coming to Doctor Who as a new viewer is this an easy one to step in and get on board with? What do you hope families take from it?

I think it’s definitely a great episode to come into. It's got a lot of action, very heroic plot, lots of fun, big mad monsters, mad ideas, cinematic ambition, all that stuff and a great cast. We have a big, epic, rollicking, fun adventure for you whether you've never seen Doctor Who or you've seen every episode. And then for long term audiences and fans of the show there are loads of lovely little easter eggs and nods to the past so it's absolutely got something for everyone.

Is it starting to feel a bit surreal now that your time on the series is coming to an end?

The workload is less so it’s lovely doing the post production on these last two specials because you're not having to write and film at the same time. As showrunner, when you're doing Doctor Who and you're in the thick of it you're doing three jobs at the same time. You're writing for episodes down the line, you're looking at all the filming that's happening and you're in the edit and post production on multiple episodes. So it's really nice now that I don't have any other episodes to think about.

I love the post production process, it’s one of my favourite bits because you're just watching teams of geniuses produce great work! So it's nice not to have the workload, it’s nice not to have the pressure of what’s coming up. I'm sort of combining having a break with finishing these episodes and working on other things so it’s lovely right now.