Probably the worst Saturday night of the year: which was why Inspector John Rebus had landed the shift. God was in his heaven, just making sure. There had been a derby match in the afternoon, Hibs versus Hearts at Easter Road. Fans making their way back to the west end and beyond had stopped in the city centre to drink to excess and take in some of the sights and sounds of the Festival.

The Edinburgh Festival was the bane of Rebus's life. He'd spent years confronting it, trying to avoid it, cursing it, being caught up in it. There were those who said that it was somehow atypical of Edinburgh, a city which for most of the year seemed sleepy, moderate, bridled. But that was nonsense; Edinburgh's history was full of licence and riotous behaviour. But the Festival, especially the Festival Fringe, was different. Tourism was its lifeblood, and where there were tourists there was trouble. Pickpockets and housebreakers came to town as to a convention, while those football supporters who normally steered clear of the city centre suddenly became its passionate defenders, challenging the foreign invaders who could be found at tables outside short-lease cafes up and down the High Street.

Tonight the two might clash in a big way.

'It's hell out there,' one constable had already commented as he paused for rest in the canteen. Rebus believed him all too readily. The cells were filling nicely along with the CID in-trays. A woman had pushed her drunken husband's fingers into the kitchen mincer. Someone was applying superglue to cashpoint machines then chiselling the flap open later to get at the money. Several bags had been snatched around Princes Street. And the Can Gang were on the go again.