Tony Curran plays the evil Callum...

What did you think of Crazyhead when you first read the script?

I think five, ten pages in I started guffawing at the blunt, frank nature of what was coming out of these girls' mouths, which was very cutting and funny. I thought it was written really well, Howard [Overman] has such originality, and the dialogue was really sharp. The characters, especially the female characters are really well fleshed-out, really entertaining and refreshing. Then of course you have the darker side of the demons who come into the piece.

How does Callum fit in to the Crazyhead world?

Callum is demon - he's one of the head demons - and it may seem like he's the top of the pile on earth but in the pecking order of the demonic world he's nowhere near the top. I always saw him as a sort of promoter - that he was trying to get this act on at some huge event like Burning Man or Glastonbury, and the act was opening the gates of hell. I found him quite endearing in that sense.

How would you describe him, is he your typical villain?

He's obviously a badass but there's also little moments where he ends up being quite sensitive. The relationship between Callum and [single mum demon] Mercy is almost like an estranged married couple - she puts him in his place.

Callum can be a nasty piece of work, but there's an absurdness to the violence, a satirical side to the whole piece. He has to pose as a psychiatrist and I don't think he's a terribly good actor, he can't help but let things slip. When Raquel is telling him things about her life he doesn't always agree with what she's saying because it's counterproductive to what he's trying to achieve, and little glimmers of his demon character come out.

Howard Overman described Callum as a 'metrosexual baddie'...

Yes, there's a certain je ne sais quoi about his approach. I loved working with Nigel the wardrobe head on it. It wasn't quite Quadrophenia but it was thin ties, fitted suits, most of the demons had very short hair, clean shaven. There's a uniformed, sharp look to a lot of the demons.

Is it fun playing the baddie?

I've played a few of them in my time! What I really liked about Callum is that he is a villain but he plays a character as well, he's got this alter-ego where he pretends to be a psychiatrist. So there was a lot of times where you could be very subtle and could approach the role in a different way, not always as the arch-nemesis.

As the show progresses episode by episode the stress of what he's trying to achieve starts to get to him. And he has these fabulous henchmen who are almost like Dumb and Dumber, they're a bit dim. He's questioning their inability to remove someone from the equation and he's mortified that they haven't been able to do it.

Within the writing there's a character who's very cunning, very conniving and utterly ruthless. But at the same time he loses his shit and becomes very, very frustrated and at times vulnerable because of the enormity of what he has to do. They're demons these people, but what makes them fun to play is that they're also very human. A lot of the comedy of it comes out of the truth of the situation.

You've played vampires and now you're playing a demon - do you find them more interesting than 'human' characters, and do you approach them differently?

I've played a demon a couple of times, I did a thing called A Soldier's Tale at the Edinburgh Festival. It was a fable written in 1915 about a demon, a princess, a soldier and a narrator with music by Stravinsky. The soldier comes back from the war and I want his soul. I guess that was the beginning of me playing a demon.

I went on to do a play at the Gate called the Boat plays. There were two of us and we'd interchange between devil and angel. There was a great moment in the play where I'm giving this Bishop a hard time and tell him he's going to hell and he turns round and says 'You think you're so good? You fell from grace!', because I'm Lucifer. And I say 'I did not fall, I was pushed!'

Playing a demonic character is similar to playing human beings as we all have those darker traits. Whether you believe in god I think one has to entertain the fact that if you believe in an almighty power there may be darker arcs. There's an animalistic and sinister side to humanity.

You've done quite a few shows or projects that are set in the supernatural world, do you believe in the supernatural or the paranormal?

There's a story I heard, or I watched it on YouTube or something - someone was telling a group of people about an extra-terrestrial experience. The group was cynical somewhat, and when he walked out they all looked at each other and someone said, 'do you believe what he said?' And the guy's answer was, 'I believe that he believed it'. I'm not saying no. I think there's got to be something going on, somewhere. Why do so many people watch these sorts of shows and find them fascinating if there isn't something in the back of our minds? Is it escapism, or is it that we think something else is afoot somewhere?