Speaking at the Edinburgh International Book Festival, he announced that the eagerly-awaited novel would be called "Exit Music", a title that he said reflected Scotland's potential exit from the UK as well as Rebus' impending retirement. 

Describing "Exit Music" as "quite a political book", Rankin said it was set in a time when people were talking about what would happen under an SNP government and the potential break-up of the UK. 

Rankin, who interviewed the main party leaders, including Alex Salmond, for The Times in the run-up to the 2007 Scottish elections, admitted that he had become more politicised as his Rebus series progressed. He also sensed "a buzz" and "a new energy" around Scotland "since the SNP came to power, in inverted commas". He claimed that people around the country were now "asking the big questions" regarding the cultural differences between Scotland and England. 

"Exit Music", named after the 2005 album of Scottish musician Steven Lindsay, also sees drinker and smoker Rebus  have to come to terms with the smoking ban, introduced by the Scottish Parliament. 

"There's an incredible tension -- Rebus realises that to have a cigarette, he'll have to leave his drink and to have a drink, he'll have to leave the cigarette. At least he gets some exercise." 

"Exit Music", the 20th Rebus novel, is published in early September. Rankin has also written about his views on Scottishness in "Scottishness:

Reflections on Identity", published by Holyrood Communications last year.