Witches never existed, except in people’s minds. All there was in the olden days was women and some men who believed in herbal cures and in folklore and in the wish to fly. Witches? We’re all witches in one way or another. Witches was the invention of mankind, son. We’re all witches beneath the skin.

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.

I think writers have to be proactive: they've got to use new technology and social media. Yes, it's hard to get noticed by traditional publishers, but there's a great deal of opportunity out there if you've got the right story.

I wrote my first short story for a competition and won second prize. Another competition came up and I won first prize. The first story was published in a newspaper. The second went out on radio.

War created bizarre allies, while peace itself could be divisive.

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?

From this height the sleeping city seems like a child's construction, a model which has refused to be constrained by imagination. The volcanic plug might be black Plasticine, the castle balanced solidly atop it a skewed rendition of crenellated building bricks. The orange street lamps are crumpled toffee-wrappers glued to lollipop sticks.