Fear is an underrated emotion. And that's why I think it's very dangerous to try and cosset children from it. A healthy scare is as good as as a healthy laugh. In fact, they're two sides of the same coin. There is a desire to shield from the knocks and bumps of reality.

It was all quite ghastly and I was very fond of it.

When I was seven or eight, I was bought a fantastic book called 'The Movie Treasury of Horror Movies' by Alan G. Frank; it became my bible. It's packed full of the most amazing photos and is still fantastic to look at.

Sci-fi and fantasy used to be a TV staple throughout my childhood. Then it just stopped dead. It was seen as culty, a minority interest.

[Toby Jones] is completely different. It's a completely different character. He's the darkest villain we've had. There was always something charming and engaging about Moriarty. There was something fascinating and actually amoral, rather than immoral, about Charles Augustus Magnussen. This guy is the purest evil. Sherlock [Holmes] is actually appalled by him.

That's what makes characters interesting. If Sherlock [Holmes] had started out being a straightforward man, we wouldn't be talking about him now. If he became one, that would be interesting. But you have to give him somewhere to go, as [Conan] Doyle did.

I always wanted to do Restoration comedy. It seems like so much fun.