Doctor Who’s latest adventure, Planet Of The Dead, starts with David Tennant’s Doctor hopping on a double decker bus in London. It’s suddenly propelled through time and space to a vast desert planet on the other side of the universe, where the bus passengers face two alien races, not all of them friendly. Among the Doctor’s travelling companions is the mysterious Lady Christina de Souza, played by former EastEnders actress Michelle Ryan.

Here, Michelle tells What’s On TV what’s it’s like to star in Doctor Who…

Much of this adventure has been filmed in Dubai – how did you enjoy it?
“It’s been brilliant, although the sandstorm we experienced there was kind of mad. Everyone was unnerved. There’s a line that Christina says about liking things extreme and I have to agree with her on that. I really loved the crazy weather.”

Can you tell us about Christina’s background?
“She’s an aristocrat and a jewel thief. She’s very cool and charismatic and someone who’s always chasing the next adventure. I’d say she’s a real adrenalin junkie, too. She’s a real match for the Doctor, but he’s quite impressed that she’s so witty and sharp. He’s someone she can spar with.”

Did doing so many stunts bring back memories of your time doing Bionic Woman?
“It did. There’s one stunt where I’m pulled up 50ft on a wire in this huge museum and I pretty much did all my own harness work. When I was first taken up I was so scared of the height. Doing the stunts gave David a chance for a rest because this time it’s mostly Christina hooking herself up to things and leaping into wells. David’s so fast, though, I’m shamed by him. We were running down a sand dune to get on the bus and my leg just buckled under me and I fell down the dune, flat on my face. It’s so embarrassing and Doctor Who Confidential has it all on camera!”

David was very impressed by your stunt work and said you were the most game of all his companions…
“Really? Well, I’m definitely game. I really don’t mind being hung upside down and stuff. That’s nice he thought that. There’s definite chemistry between them. And he’s quite bowled over by her.”

Any kissing between the Doctor and Christina?
You’ll have to wait… All I’ll say is she’s a classy girl.”

How does she react when she gets to this inhospitable desert planet?
“She’s definitely taken aback but excited. Everyone’s really scared when the bus lands there, and she’s a little scared, too, but that’s part of the enjoyment for Christina. When most passengers are freaking out she kind of takes charge and says I’m going to lead you through it.”

Have you always wanted to be a Doctor Who companion?
“It’s not something I’ve really thought about before. I hadn’t actually seen any episodes before so came to this new, but I was aware that it was a huge hit. When they were taking photos of me on set to have my Doctor Who doll made, I realised how cool it is to be a companion.”

What did you make of the aliens in this episode?
“We did see a couple of Tritovores on set and they were really great. A lot of what we did was on ‘green screen’, but we were shown before what this huge bug would look like, and it was very scary. If you came across one of those in the desert you’d be well petrified.”

Is the door open for Christina’s return?
“It’s left open, yes, but she’s a bit of a commitment-phobe. At the end of the episode it’s quite fitting that she and the Doctor go off on their separate ways. She’s not the sort to stick to doing the same thing. But saying that, if they needed her and the time was right, then maybe she would come back.”

Are you prepared for all the crazy Doctor Who fans?
“Yep, as with Bionic Woman I seem to be doing shows that have a history – even EastEnders had that. So I’m prepared.”

Would you be tempted to work in America again after your experiences on Bionic Woman?
“I’m just really keeping my options open. I didn’t expect Bionic Woman to come along and take me over there. Every job is like an adventure.”

What’s the difference between filming an American series and a British drama?
“The budgets are probably bigger over there (laughs), but the hours are longer. I guess everything is just bigger. If you’re a lead character over there someone will literally get your chair for you and you’re expected to accept that sort of thing. Over here, everyone just mucks in together and you go get your own chair.”

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* Doctor Who’s latest adventure will be shown on Easter Saturday, BBC1, at 6.45pm