Ian Rankin makes no bones about the fact that Edinburgh is an essential character in his bestselling series of police procedurals about dyspeptic and cynical Detective Inspector John Rebus. In Toronto on a 24-hour junket for Book Expo Canada last month, the dark-haired Scottish writer took time out from book signings to chat about his own connections with Edinburgh. "I started writing the books because I wanted to make sense of Edinburgh," he said candidly, over a glass of water -- unlike his creation Rebus, who never seems to say anything without a double whisky to hand.