MOST everything Mark Gatiss is involved with, be it on the small screen, radio or in book form, has a dark side. It's either black comedy, a murder mystery or horror. So, is there something wrong with him?
"I've never had it phrased like that before," he laughs.
"It's only the same 'something wrong' that's probably wrong with you I suspect and with a lot of other people.
"We were always being asked 'is it some terrible inner darkness?' I suppose it is but the healthiest response to it is comedy rather than going into the streets with an Uzi."
"We" are, of course, Gatiss, Steve Pemberton and Reece Shearsmith aka The League Of Gentlemen, who went from BBC radio show to cult TV series, movie, arena tour, book, T-shirt, action figures...
I'm one of those who made the trek up to Royston Vasey aka the village of Hadfield in North Derbyshire where the series were filmed.
"I'm so sorry," he says.
Quite. It's a weird and fittingly dark place.
Famously the locals initially resented their presence but when I went they were selling self-made League Of Gentlemen location maps in the corner shop.
"I still have a copy of the Wakefield Courier with the headline 'Plague of Gentlemen'," he laughs.
"After the paper credited us with turning round the local economy for a while they kind of came on board."
Not that the cast and crew stayed there during filming.
"There's nowhere to stay. It was bit of saga as we never had a fixed hotel. We went through so many in Manchester and Hyde – which turned out to be literally opposite Harold Shipman's surgery – one in Buxton, which was lovely, but we'd always set our hearts on a Hilton on the Moors. Finally on the third series we insisted we stay there and it was the bleakest of the lot. Like an internment camp."
When the trio (and off-screen contributor Jeremy Dyson) finished promoting the Apocalypse movie three years ago, each went their separate ways.
So it's all over?
"Well no. Steve and Reece are currently filming their own project which is very League-ish, called Psychoville," says Gatiss, who now lives in Islington, London.
"We would love to do something together again but we were together for 12 years almost constantly. We wanted a proper break and to do something else. I would never say never because I would love to but everything has its season... or three seasons."
Gatiss is busy to say the least. As well as appearing in Doctor Who (two episodes of which he also wrote), the 42-year-old has been involved in writing and appearing in ITV1 drama Poirot; he's filmed BBC dramas Purves and Pekkala and Sense and Sensibility; wrote and starred in Radio 4 comic thriller Murder Every Monday and voiced a third series of Radio 4 sci-fi sitcom Nebulous. He's also just finished filming Clone, a new sitcom for BBC 3 created by Adam Chase, one of the key writers of Friends.
Off screen Gatiss is ready to publish a third novel, Black Butterfly, another adventure for his Victorian spy and all-round cad Lucifer Box.
Do you get any time off to enjoy yourself?
"This is it, this phone call."
My turn to apologise.
"I'm in a privileged position to do things like Christmas ghost stories which I've always wanted to do, since I was about seven."
He's interrupted his editing of it to speak to EG. It's called Crooked House and it'll be on BBC 4 this festive season.
Gatiss has also been working on an updated TV version of Sherlock Holmes for the BBC with the new Doctor Who boss.
"The pilot has been greenlit. Steve Moffat and I have had this idea for a modern Sherlock Holmes for a long time. It was hatched on trains back and forth to Cardiff for Doctor Who. I'm tremendously excited. It's another dream come true.
"I love that idea that Holmes would turn down a fortune to investigate a bank robbery but if someone came to him and said 'my husband has always had white toast but this morning he had brown and now I can't find him'."
Any ideas who will play Holmes?
"Plenty. But I can't possibly reveal who."
As part of the Mayhem Horror Festival he'll be showing and talking about clips from film and TV that scared him the most as a child.
"One of them is Blood On Satan's Claw which is a very underrated horror from the 70s. And there's one from the TV series Hammer House Of Horror called The Two Faces Of Evil. It's a family driving to a holiday and it starts to pour down. They pick up a hitchhiker in a Sowester and you can't see his face. He attacks the driver and you just see that he has this extraordinary long fingernail that he scratches down his face... it still gives me nightmares thinking about it."
So how does he mark Hallowe'en?
"I generally bathe in the blood of a virgin. Which is so hard to find."
"No, I love it. Derren Brown and myself were going to go to a haunted house with a group of friends but I can't do it because I'm coming to Nottingham. We'd have to have stayed up until six in the morning and I couldn't imagine stumbling out of there, doing Saturday Kitchen, which is what I'm doing, then getting the train up to Nottingham and talking lucidly."
Mark Gatiss presents an illustrated talk called What Are You Scared Of? at Broadway on Saturday November 1 from 3.30pm. Visit www.mayhemhorrorfest.co.uk for more details or call 0115 952 6600. Black Butterfly by Mark Gatiss is published by Simon and Schuster on Monday, price £15.