Interview: Mark Gatiss, actor and writer

MARK Gatiss is apologetic. "I'm slightly worried about being ubiquitous," he says. It seems that the gods of scheduling have decreed October is Gatiss month on BBC4. A History of Horror with Mark Gatiss begins on the 11th; his take on the HG Wells novel The First Men in the Moon goes out on the 19th; and then by some fluke of fate, he tells me, "unbelievably, the BBC are repeating Crooked House in October, when I'm in every programme already. I don't get it."

Few fans are complaining, though, for we know that Gatiss operates to a high standard and the results are always worth watching. Through his work as one of the League of Gentlemen, to roles in everything from Agatha Christie to Nighty Night, The Wind in the Willows, and Fear of Fanny, Gatiss has proven himself one of Britain's pre-eminent character actors.

As an author, he invented the deliciously amoral adventurer Lucifer Box, star of three novels, and has penned a raft of screenplays, including episodes of his beloved Doctor Who. And I haven't even mentioned Sherlock, the modern-day update of Conan Doyle's iconic sleuth, which he conceived with Steven Moffat. It was an instant sensation when it aired this summer, and had us glued to our sofas, squealing with delight.

Gatiss has loved Holmes wholeheartedly since he was a lad, but was he surprised by the reaction? "Yes and no. We knew from the start that we had a good idea. People sometimes forget that they were very short stories, brilliantly written by an incredible writer who was years ahead of his time. They're meant to be fun and enjoyable and thrilling. Sometimes it becomes so much about the trappings. We thought, if you remove all of that, you get back to what the characters are.

"All people are really interested in is the relationship between John and Sherlock and Moriarty. It's the human element which is what, in the end, lasts. The deduction is thrilling, but it's the moments in between that actually get people."

It was vital to nail the casting. "Benedict Cumberbatch was the only person we saw for Sherlock. It's very difficult to get someone with that amount of command, which he really has."

Watson was much harder to cast – until they saw Martin Freeman. "The actors had an immediate spark. When Martin left the room after reading with Benedict, Steve said, 'Well, there's the series before our eyes!'"

Three more episodes have been commissioned, but fans must remain on tenterhooks until roughly this time next year. "My maxim is what Wilkie Collins used to say, 'Make them laugh, make them cry, make them wait.' It's an adventure series. It's great fun to be on that sort of cliffhanger."

At least all three episodes are available on DVD, with the added bonus of the pilot, included to prove a point. "Annoyingly, a story had gotten into the tabloids that we'd made a pilot for 900,000 – which we didn't – and that it was so bad it was never going to be shown. This story wouldn't go away. We were originally were going to make six, 60-minute episodes. Then the BBC said, 'We want to make this more like event television, so we want three 90-minute episodes." We had to remake episode one and expand the story. For the sake of the director and the fact that it's very good, we thought, 'Well f*** it, we're just going to show people the pilot.' It's different, but we would have been very proud to put it out."

Horror films are another of his passions, so Gatiss was thrilled to get the call asking if he'd explore their evolution in documentary format. "I said you can't do (it] justice in three hours, so the only way is to make it as personal as possible. I have to miss out some very famous films, and films I love very much myself, but otherwise you just end up making a list programme."

Episode one kicks off with Lon Chaney's Phantom of the Opera. "That's a conscious decision to start with Hollywood. And the episode ends in the 1950s, with the end of the golden age of Universal, when sci-fi took over. It ends rather neatly with Lugosi's stage tour of Dracula, which wasn't much of a success. It's as if horror is dead, and then of course, it comes back from the grave with Hammer.

"The second episode is mostly Hammer and some of the supernatural films like The Haunting, which are different but of the period. Part three is essentially America's response to Psycho, and Romero and John Carpenter and Tobe Hooper. It ends with Halloween.

"We made the decision to stop at Halloween because first of all you've got to stop somewhere, and secondly, the film is a masterpiece. But it was so successful, it sort of stopped horror dead in its tracks. Horror became slasher movies. There are exceptions, obviously, but mostly it's Friday the 13th and Freddy Krueger. The supernatural horror film disappeared for a while."

Anticipating the inevitable complaints, he re-emphasises the personal nature of this programme. "In every episode I tried to spend time on a film which I think is a bit neglected, such as Son of Frankenstein, Karloff's last one as the monster. It's actually more like a swashbuckler. It was made in 1939, which people always say was the best year in Hollywood, and it's sumptuous. It's Lugosi's best performance, as Igor. And the actor who played Basil Rathbone's little boy, Donny Dunagan, is still alive. He's 75, and turned out to be the highest decorated Marine in US history."

Given his extensive knowledge of the genre, were there any surprises? "Weirdly, considering that I know a lot more about the Universal and Hammer films, than the films in part three, in a way it was my favourite to do. Talking to George Romero and John Carpenter and Tobe Hooper was brilliant. I fell in love with their films all over again, especially Romero's stuff."

Texas Chainsaw Massacre makes me laugh like a drain, I tell Gatiss, who agrees that it's highly comical in places. "I asked Hooper, 'What were you thinking, what did you imagine had gone on in this sort of journey, and what are they trying to do?' and he said, 'Oh, I just thought it was a bad day for everybody. Bad day for Leatherface. I mean, who are these kids who come and spoil his life, you know?'

Why do we pay to have bejesus scared out of us? "Because a good scare is as good as a good laugh," he says. "It's the flip side of the same emotion. But there's a big difference between being nauseated, and being horrified. For me, not all, but a lot of modern horror films are simply torture porn. As George Romero said to me, 'They're very mean spirited.' There's no satire, no point being made, they're just what they look like, and in that case you might as well just go dig up a grave and go look at a dead person. There's no art to it."

Far less frightening, but no less fascinating, is The First Men in the Moon. It's rarely filmed – the last time was in 1964, from a screenplay by Quatermass mastermind, Nigel Kneale.

"When opportunity came up – talk about ticking my boxes! All of Wells's big stories are owned by Hollywood. This one's a loophole. It hasn't been done to death, like War of the Worlds, but it's actually one of his big books. I was able to be much more faithful to the novel, because, in a funny way, it being for BBC4, there's less money and so there's less interference. It meant I could go back to the source. In the 1964 film, because it was made in the middle of the space race, when they land on the moon they have to have space suits, because people knew what the moon looked like. I thought, I'm going to do Wells's version – which was that there is an atmosphere on the moon.

"Also a part like Professor Cavor is why I wanted to become an actor: it's my ideal part, the closest I get to being Doctor Who! It's that sort of mad scientist role that I've always hankered after."

It's been a good year for work, he reflects, one in which he got to play Mycroft Holmes and Malcolm McLaren, in Worried About the Boy. And in December, he'll be treading the boards in an all-star production of Alan Ayckbourn's Seasons Greetings, at London's National Theatre.

Whenever we catch up, I ask Gatiss the same question: is he more actor, more writer, or evenly divided? "Sometimes it doesn't feel so 50-50. Because of being an exec on Sherlock, I spent the first four and a half months of this year mostly looking down the camera on set in Cardiff, freezing my nuts off, so sometimes it can feel a bit skewed, but on balance it all works out."

• A History of Horror with Mark Gatiss airs on 11, 18 and 25 October and The First Men in the Moon airs 19 October, both on BBC 4. Season's Greetings starts at the National Theatre on 1 December.