EXCLUSIVE: Mark Gatiss interview

"To be absolutely frank, the problem with trying to focus on one story about the beginning is that there are so many stories. There'll be howls of protest from certain quarters because there are some people not in it. It's a drama about the creation of Doctor Who, it's not a documentary and, therefore, I had to focus on a small number of main characters. And a few of the other characters have to slightly merge. David Whitaker's not in it. Mervyn Pinfield is and he sort of absorbs David Whitaker's role. To a lay audience, who don't give a monkey's about the difference between a script editor and associate producer, they would just be bewildered.

It hurts my inner anorak, it hurts me. But, at the same time, I had to approach it very much the way I would do if I didn't know anything about the programme - it's a drama about people and the fun mechanics of the creation of the show.

The big casualty really was, in the first draft or two, the creation of the Daleks had essentially meant the relationship and the difference between Terry Nation's [the creator of the intergalactic pepperpots] and Ray Cusick's [the designer of Skaro's finest] fate was sort of the B-plot. But it was too broad, it was too wide-ranging, it just needed to be focused.

I hope that if you don't really know any of these famous Doctor Who stories that you'll be surprised by some of the decisions. It's interesting when we were editing it, some things you just stripped out because actually that's a detail too far.

It leaves residual touches, in a funny kind of way. There's a wonderful memo about when they were thinking what the TARDIS would be and someone says, "It could be covered in invisible paint!" I love that! [Laughs] And, actually, now I've got William Hartnell suggesting it over a Chinese meal. You have to work out the detail of what's interesting to a die hard fan and what's also accessible to the public."

"I think that story [Terry Nation and Ray Cusick] would make its own film. The story of the Radiophonic Workshop would make its own film. And then, in the history of the programme at different times, there are things that would be fascinating to see dramatised. Whether or not it would actually hold a ninety-minute film, I don't know."

"I guess so, you never can tell. Because, if you're involved, it seems baffling - why would anyone be interested? [Laughs] But then, that's what it must feel like to be someone who was involved with Doctor Who at the beginning. For Verity Lambert, who I knew a little, she was an amazing woman but I think to her very end she was slightly baffled by the fact that Doctor Who was the thing that she would be most remembered for. So the idea that I guess one day someone might make a film about the making of An Adventure in Space & Time and then the universe will implode. [Laughs]

"As an exec on it, I was following it, I was there every day and I was there during the entire post-production, edits and everything so it's more involved process because there are director's decisions on Doctor Who and Six Floor [location of the people at the BBC with "power"] decisions which have a huge amount of say, I'm very pleased to say. But in the end, it's not my baby. So Doctor Who is about the only thing I write for that I'm not actually behind the scenes for as well. It's very special to me, I'll carry on as long as they'll have me. Space and Time was very hands on, mostly."

"The Doctor Who story I've always wanted to do is about Laika the dog, the Russian dog they put in space. I think I had a dream about it once where there was just him in his capsule - what a lonely thing! I thought, wouldn't it be fascinating if something else got in, like The Quatermass Experiment? And Laika came back to Earth, still alive, but not alone…"

"Ooof, not for Sherlock! [Laughs] I'm going grey just at the prospect! Actually, I seem to remember Russell [T Davies, former showrunner] harbouring a desire to do a live Doctor Who - "Forty-five minutes to save the world!" I remember David blanching when he was telling me about it [Laughs], even though we'd done Quatermass. I think that was very ambitious for live TV. It's possible. It would probably have to be a very contained thing where the Doctor was trying to get out of a lift or something. But it's a good idea, why not? But Sherlock? Absolutely not. [Laughs]

"Benedict commissioned it by virtue of saying it's going to happen. Which is a brilliant way of commissioning anything! I've commissioned the next ten just by walking the red carpet with a loud-hailer. [Laughs] Not yet as we haven't finished Series Three yet - we have plans though…"

"I'll tell you an odd thing about that story, it was made first of that season. It was the next thing after the Christmas, it was made in the summer and wasn't shown for over a year after it was made by which time several other stories in that season were also about absentee fathers and sons. By the time Night Terrors came along one of the reviews said, "What's going on??" And I thought, "But I did mine first!" So I don't know if there was any kind of plan.

To be honest, the reasoning behind it was I thought it would be quite interesting to do a father and son rather than the obvious thing, I guess, would have been to do a mother with a child. And I thought it would just be more interesting to make it about a father's trouble. I thought it was a less obvious way to go with a troubled child. It was a cuckoo in the nest story so, again, but actually the father's worrying is quite interesting because it's not quite the same. He's unemployed, his wife is working, he's feeling all those kinds of pressures, as well, to sort of provide.

I was very keen to do that because I hadn't done a modern day one; I love that idea of, it's sort of a bit more like Russell's era. And getting people like Danny Mays and Emma Cunniffe just really made it. And it's got scary dolls in it! [Laughs] I went to the Experience [the Doctor Who Experience in Cardiff] the other day and I was so chuffed to see them in the corner. They're really horrible. There's something intrinsically terrifying about dolls."

"It's done, no no. I've read it. It's fantastic. I'm very excited about seeing it."

"You can't trust anything anyone says to the Royal Family! [Laughs]"

"I can't answers these questions Cameron, you know I can't. [Laughs]"

"I've seen it a thousand times! Chuffed to bits with it. It's very moving and the cast are magnificent; David particularly is really quite something. It's a very moving story and fun."