What’s next in store for the trio on this adventure?

Well, this adventure involves monsters, someone dressed as a pirate, real pirates, an underlying love story, and it involves somebody finding something in themselves to make a commitment to another person to look after them. It has all of those things, and sword fighting, so I don’t think you could ask for more!

For this episode, we have the return of the Sea Devils, which everyone is very excited about. How did they compare to working with other Doctor Who monsters? Obviously we have Craige (Els) was back in a costume so you got to work with him again!

That was quite an interesting dynamic. Craige is great, but when he was Karvanista we were mates whereas with the Sea Devils it’s a bit of a different story - so it made the coffee breaks interesting! It was also, from a performance point of view and so on, really odd because they were physically threatening. In Doctor Who some of the monsters are not necessarily bigger than you are or physically different than you. Whereas with the Sea Devils…put it this way - if they walked into a pub, nobody is going to take them on!

Did you know much about them before filming or did anyone need to bring you up to speed on the history?

I knew a little bit about them and then Ray (Holman) our Costume Designer had a chat with me about their history, and how they’ve not been around for a while, so I knew what he had told me. Like all the elements of Doctor Who, the main actors are a small part of the fabric of what makes it work. The designers, the art department, the prosthetics, wardrobe and all those things make it work on the day and then afterwards, the post production, the music; all of those things make what you see so much better than what you’re doing on the day. And when you do it on the day and it’s good, you know it’s going to be brilliant on the telly because all of those bits get added.

You've got quite a striking pirate costume in this episode. How did that one come about?

It starts out a little joke between the characters – between Yaz and Dan - and then events take over and he never gets the chance to change!

Was there anything about the sets that really impressed you?

I’ll tell you what impressed me - having a ship! I just couldn’t believe it. It was a full ship built in the studio next door to the TARDIS. So we were filming a previous episode, and then you walk in next door and there's a ship that has been built. It absolutely floored me, honest to God it staggered me - the workmanship and the level of detail in it. It literally blew me away.

There are some new guest actors in this episode. How was it welcoming them into the Doctor Who family?

It's always good, particularly when they’re good actors! Crystal was familiar with Cardiff because obviously she has been in Casualty and when she was on set there she was thinking about what it was like in the Doctor Who studio - on the other side of the wall - so it was interesting to see it from that perspective. It was Marlowe’s first job and he was he was brilliant. Everyone wanted to look after him but he was just so accomplished, me and him were hanging upside down for half a day just having a laugh. Which is an odd way of getting to know someone!

How was your experience filming this special compared to others?

To get on the beach, on the coast, all of that setting and just being outside was good. But the main thing for me was just the ship, filming on the ship and just seeing the way it's done. There’s a massive screen for all of the CGI and I've never seen anything like that before - it was just so impressive.

Is Dan still involved with the Doctor and Yaz in this episode in terms of the development of their relationship?

I think it was probably a surprise to both the Doctor and Yaz that it was so obvious to him that there was feelings between them. And I think as a character he is probably not the most obvious persons to be the matchmaker. Because he comes in as an ordinary bloke you would suspect is so bemused by the world that he's in is too busy to absorb what's going on around him to notice. But because the bond between them is so clear, and because I think as well as he says to Yaz in the New Year’s special - sometimes if you've got feelings for somebody you just have to act on them because otherwise if you don’t it will be too late.

Were you involved in any of the sword fighting for this episode?

I'll be honest with you - I think they missed an opportunity because I was so desperate to do a few somersaults and swing on ropes - I really wanted to be a proper pirate! I got a bit done but if it was down to me I think there was a big likelihood that I wouldn't have been in the show at all because I think I would have killed myself at some point. I was like a kid on the set, climbing up ropes and everything - the stunt coordinator kept going “Get off, get off!” There’s a bit of rope swinging a bit of sword fighting and all that. Because we knew it was a special and the way the story was we played it for fun - it was written to be big and bold and that’s what it was.

How does it set us up for the final special? Does it gives any clues about what to expect?

You know there’s something big about to happen. You can see the change in the Doctor and change in the dynamic and you just know there’s something big around the corner.