Edinburgh International Book Festival: Ian Rankin

After the release last year of Standing in Another Man's Grave, Rebus fans were thrilled to see the curmudgeonly detective back on the trail of killers, gangsters and corrupt citizens, with the action transposed for most of the book to the lonely stretches of the A9, as he followed a trail through a string of Highland towns. After what Rankin describes as the "freeze frame" at the end of the previous Rebus outing, Exit Music, the award-winning author was unsure if the detective would, or could, return to active duty.

"A lot of people didn't believe me," he tells a packed crowd in the Edinburgh Book Festival's most capacious tent, "but I thought that would be the end." Thankfully for the legions of Rebus fans worldwide, rumours of the detective's retirement were somewhat exaggerated. A now 60-year-old Rebus returned in ...Grave under the auspices of the Cold Case Unit. "The first few pages of that book were really nerve-wracking," Rankin admits. "I hadn't written about him for five years." Luckily, Rebus hadn't gone anywhere. Rankin describes the detective sitting in a room inside his head, just waiting to be let out again so he could spark up a cigarette.

Although Rankin had already written two novels using Complaints and Conduct officer Malcolm Fox as a protagonist, and had considered switching to a female lead – in the form of Siobhan Clarke, Rebus's erstwhile sidekick – the lure of his familiar sleuth proved irresistible, and so he was revived. This November, Rebus returns again in Saints of the Shadow Bible, a title taken once again from the song lyrics of Rankin's late friend Jackie Leven. The extract he reads doesn't give much away, other than the fact that the action takes place before this year's amalgamation of the regional police forces into Police Scotland, and that Rebus is back on the force full-time, although now ranked as a Detective Sergeant, one grade below his former protégé, Clarke.

Rankin's prose is as terse and witty as ever, and Rebus's appealing cynicism is undiminished. Rankin himself admits that as an author, he has grown up in public. Early Rebus novels contained more of Rankin the writer, and less of the Rebus his readers came to know so well. Now on his 19th Rebus novel, his style has continually been refined and enhanced, bringing Rankin a justly-deserved reputation as one of Scotland's best crime writers – no small feat considering the fierce competition. Now determined to keep the film and TV rights to his most enduring creation until he can be treated with the same care and attention as his Scandinavian equivalents, the only bar to Rebus's continued supremacy is his age. Rankin says he can't see him as a private detective, so we may only have five years left; but the character, and his creator, have already assured their prime spot in the annals of tartan noir, and crime fiction in general.