PW: For the benefit of American readers, what exactly is "Irn-Bru," which appears so often in your novels?

Ian Rankin: Irn-Bru [pronounced "Iron Brew"] is a Scottish soft drink; it's bright orange, sugary and fizzy, and seems a staple of the working-class diet. It's also a great hangover cure, which might explain why so many characters in my books drink it.

PW: And for readers unfamiliar with John Rebus, tell us about the Edinburgh detective and his evolution.

IR: Rebus is a dark and brooding character who burrows into other people's lives [through his job] as a way of not dealing with his own problems. In the early novels, he was more of a cipher, a way of telling the story and leading the reader through the plot. As he developed, he became the plot. I grew fascinated with him, feeling there were secrets he was keeping from me. He's haunted by the ghosts of every murder victim he's ever dealt with. And this is important to the arc of the series: he lives in real time. He's 40 when we first meet him [Knots and Crosses], and 55 by the time of the latest novel. He has slowed down, aches in places where he didn't used to ache, and sees a younger, smarter, fitter world developing at his heels.

PW: What was the genesis of your new novel, A Question of Blood?

IR: A fan once asked me if I had any plans to write about Edinburgh's private schools, which are an anomaly in Scotland. I started to think about the effect this system has had on Edinburgh. But what plot would I use? One was staring me in the face. The massacre of school children at a kindergarten in the town of Dunblane is a fresh memory for most Scots. Then I decided I would write about outsiders, about people who don't fit into society. Slowly, I began to see my plot taking shape.

PW: Edinburgh is very much a character in your work with its gloomy architecture, weather and people. How do you feel about the place?

IR: On the surface, Edinburgh is the most beautiful city in Europe, a place of history, tradition and culture. But scratch that surface and you find poverty, drugs, prostitution and malice. Edinburgh is good at hiding its sins from the world, and the tension between surface and what lies beneath makes it a fascinating place to write about.

PW: You've certainly helped put Scotland back on the literary map. Is there a Scottish literary renaissance under way?

IR: When I first started writing, there seemed to be very little going on in the contemporary Scottish novel. Then Alasdair Gray came along with his magnificent, sprawling novel Lanark [1981], and that changed the whole landscape. Nowadays, you can't walk 50 yards without tripping over a writer. J.K. Rowling lives not two streets away from me, and another recent success story, Alexander McCall Smith [author of The Number One Ladies' Detective Agency], lives two doors away.

PW: Rebus's colleague Siobhan Clarke occupies a central role in A Question of Blood. Have you considered a novel with her as the protagonist?

IR: I introduced Siobhan as just another of his colleagues, but she got beneath my skin, and female writers (and female cops) started telling me they liked her and found her realistic. Some people see Siobhan as my "insurance policy" and maybe they're right. If Rebus were to retire, I think she could handle a whole book on her own.

PW: When you received the Order of the British Empire, did you get to meet the queen? Does she read crime fiction?

IR: I received my OBE in Edinburgh rather than London, so I didn't get to meet the queen. Does she read crime fiction? I doubt it, certainly not the gritty and violent sort. But quite a lot of Britain's politicians are avid crime [fiction] fans. Maybe they're looking for ideas!