Ryan Sampson ('The Things I Haven't Told You')

The latest, and arguably most anticipated, of BBC Three's drama pilots arrives on Monday. The Things I Haven't Told You - a dark, heavily mysterious teen drama - follows the events before and after the suspicious death of troubled 16-year-old Aisling Hunter. But who was responsible for her demise? And what secrets was she hiding? Seriously intrigued, we tracked down star Ryan Sampson to find out more.

So, what's it all about then?
"Well exactly! Funnily enough, we really didn't know ourselves for quite a long way into it. In rehearsals we only got told the bits that we were doing! It's centred around the mysterious death of this girl Aisling Hunter, and how that reverberates through the people that are around her."

Have you seen the finished version yet?
"I have, yeah. I really liked it. It was interesting to see how much it changed from the script to the screen. The end wasn't what I thought it would be and it took me aback. Very intriguing!"

How would you describe Mark, your character?
"A loner, outsider, with a penchant for surveillance. He likes recording events and archiving instances. This gives him a vantage point and enables him to see everything that goes around him."

Does he do anything with this information?
"Without giving too much of it away, I think he has his own grudges that he bares and retribution is more of an objective for him, rather than being in with the in-crowd. He doesn't really care about popularity, he floats above all that stuff. For him, it's more about twisting the knife."

Do you know much about Mark's background?
"Yeah, I do now. I needed to, to understand how it fitted into the whole story and the arc of it, but like I say, we only know our own pieces."

What sort of things did they tell you?
"I've been told about my relationships with other characters that come to the fore later and influence things. We did quite a bit of work on things that you don't see, that are behind [their behaviours], if you know what I mean. That's quite unconventional for a pilot, I suppose, but we're absolutely looking at the long-term. It gives great potential for a series, because there's so much bubbling under the surface that would be great to explore."

Do you know how the story would develop if it went to series?
"Should it go ahead, each week would feature a different kind of person and how their life has been changed by [Aisling's death]. So you get a different kind of piercing insight into one fragment of the story. It slowly builds up to fill in this puzzle."

Have you watched any of the other pilots so far?
"I saw Phoo Action. Erm... yeah. Wow. Interesting."

What did you make of it?
"I didn't quite get it at all. I thought it was quite an unusual choice for the Beeb. Primarily I lost interest because the lead character had no eyes, because of her fringe. I think it could have been incredibly interesting but didn't quite hit the mark for me."

And I hear you've filmed a part for the new series of Doctor Who. What can you tell us about that?
"It was filmed over two episodes, and it was the most fun job I've ever done. I was playing a kind of 'is he good, is he bad?' character, who is pivotal to the episode. He's working with these aliens called the Sontarans, who they've reinvented from the classic series. He's not quite sure how the land lies with them and who's controlling him. That sort of comes to bite him in the arse! It was so huge and over-the-top, I hope it doesn't look ridiculous when it comes to the screen."

Do you play a teenager?
"Yeah, he's 18."

How did you find the Doctor's two companions?
"I got on with them both really well, but they're kind of opposites to each other. Freema [Agyeman, aka Martha] is kind of bubbly, a little bit tomboyish and fast-talking. Then there's Catherine [Tate, aka Donna], who's a little more reserved and got a really dry, sharp wit."

How did you get the part?
"I just auditioned. It said on the script... actually, I'm not sure if I am allowed to say any more! They're so funny about this stuff, as you'd imagine at Doctor Who. At the end of the day you have to give your scripts in to them so that they can destroy them. It's crazy! Each script is watermarked with your name in really big letters, so if it gets to the press they know who did it."

Are you a big fan of the show?
"I'd never seen it before in my life but now I'm absolutely hooked. I don't know if this is the right thing to say or not but it's so kitsch! It's like nothing I've ever worked on before."

The Things I Haven't Told You airs Monday at 9pm on BBC Three.