What's the difference between truth and fiction? Ian Rankin often opens his novels with graphic details of real-life crimes. John Rebus, Rankin's Edinburgh-based maverick detective, has seen it all before and understands that the difference is fairly murky.

The Naming of The Dead, the sixteenth and latest Rebus book, meshes the worlds of truth and fiction rather uniquely. The narrative structure of the book is supplied by dramatic events in July 2005 and the G8 conference. The plot reveals itself against a backdrop of real time when the attention of the world (or at least the world's media) was elsewhere. It is always useful for a writer to have such a framework – but the rest of it has to offer a sense of reality too.

Ian Rankin's talk offered an insight into many aspects of his writing. Detective characters, he explained, look at the world to ask awkward questions. Their business enables them to access information both public and private. The fortunate reader can savour the clues as Rebus works on them against the grey and sometimes secretive background of the real city of Edinburgh. No crime can be dismissed as unsolved – it's just a matter of waiting for the right technology to appear and be applied. In Rebus' case, this can be problematic. He's not an internet fan, and needs all the techie help lent by his attractive female colleague Siobhan. Rebus' modus operandi is that of the old hand, following his instincts but getting his man in the end – and how often is that man linked with the ubiquitous criminal Ger Cafferty?

Rebus is approaching 60. Even die-hard cops need to hang up the notebook one day. Real-time Scottish Police officers were definitely not, unsurprisingly, amused at suggestions by avid readers that the official retirement age be raised to 65 just so Rebus could work longer. Will Siobhan run the show in the next book with the assistance of a pensioned-off Rebus? Rankin thought this was a real possibility.

Rankin delivered a fascinating talk, after which many listeners left with their own signed copy of the new title. They should enjoy it.

Mary Dunk