Rebus is off the case - quite literally. A few days into a murder inquiry following the brutal death of an Edinburgh art dealer, Rebus blows up at his superior, DCS Gill Templer, and is sent into purdah. Which, in his case, means the Scottish Police College, sited on the edge of a village in central Scotland. Rebus has been sent there for 'retraining'. In other words, it's his Last Chance Saloon. He is not alone. At the college, he is put into a group of similar officers - people who have a problem with the very institution which houses them. They are given an old unsolved case to work on. It will hopefully teach them the merits of teamwork, while allowing professionals the chance to assess this unholy 'wild bunch'. But there are those in the team who have their own secrets - secrets not unconnected to the very case they've been given - and they'll stop at nothing to protect them. As if that wasn't enough, the Scottish Crime Squad have a favour to ask of Rebus. They think they've found someone who can deliver the inside info on the east coast's biggest gangster, 'Big Ger' Cafferty. All they need is a link-man, someone to act as go-between. They've decided on Rebus whether he likes it or not. Meanwhile, back in Edinburgh, newly-promoted Detective Sergeant Siobhan Clarke must work the case of the murdered art dealer, a case which will take her closer to Cafferty and his world than she could ever have anticipated...