I've always written. At the age of six or seven, I would get sheets of A4 paper and fold them in half, cut the edges to make a little eight-page booklet, break it up into squares and put in little stick men with little speech bubbles, and I'd have a spy story, a space story and a football story.

I took the first James Kelman novel, 'The Bus Conductor Hines', home to my dad. I thought, 'My dad will like this; it's written in Scots.' But my dad said: 'I can't read that.' He was reading James Bond and John le Carre. That was part of what attracted me to crime - the idea of getting a wide audience.

I'm interested in Scotland now and then, how it's changed. I want to get the reader to think about that by thinking about something from the past. How has society changed, how has policing changed, have we changed philosophically, psychologically, culturally, spiritually?

It seemed to him a very Edinburgh thing. Welcoming, but not very.

I started writing novels while an undergraduate student, in an attempt to make sense of the city of Edinburgh, using a detective as my protagonist. Each book hopefully adds another piece to the jigsaw that is modern Scotland, asking questions about the nation's politics, economy, psyche and history ... and perhaps pointing towards its possible future.

You wouldn't think you could kill an ocean, would you? But we'll do it one day. That's how negligent we are.

You need a great idea, but then you've got to carry it through. If you get it right, you're going to be a critical success. But not everyone who works hard gets it right, or has the success they deserve: there's an element of luck.