Here he finds five other maverick individuals whose careers have also jumped the rails: for all, Tulliallan is the last opportunity to reform. To retrain them in the art of working as a team, their martinet instructor, a retired detective chief inspector, resurrects an old, unsolved case: the murder, six years earlier, of Eric Lomax, a small-time Edinburgh criminal. Both Rebus and DI Francis Gray, another of the group, had worked on the investigation.