What is interesting, as well, is how much power homicide detectives have and how much respect. They are kind of rock stars, especially in New York. There are not that many of them.

What is interesting, as well, is how much power homicide detectives have and how much respect. They are kind of rock stars, especially in New York. There are not that many of them.

To me, the difference between New York and London is that things are boring and staid in London. But even the sh-tty diner and bars here are kind of exciting for me. Downtown is funky, West Village is beautiful with the cobbled streets, but I love going uptown because you then you go, "F-ck, I'm in New York!" You see all the skyscrapers.

New York cops are very specific in terms of the way they talk and the way they handle themselves. All these cliches that, as an Englishman, I thought were from a bygone era or were a bit of poetic license with cop shows - the more you hang out with them, the more you realize how real that jargon is.

In Britain, you do your job. When you do an American TV show, there is a sense of being one with the crew, and there is a leadership element, which was a learning curve for me because it is very different culturally. In Britain, you just do it, leave and say, 'Thanks.'

People say that New Yorkers aren't friendly, but I think they're more friendly than Londoners. Here there is a front-footed nature of Americans. You can go out on a night out and meet 10 random people and stay in touch with them, whereas that's not going to happen in the same way in London.

What I like about the 'Underworld' thing is that it's a mix of cool genres, as well as creating its own message.