John Rebus is charged and on trial for a crime that could result in a life sentence in prison. Although that's not the first time the renowned investigator has done so, it very well could be the last. Why did a decent man cross the line? Or have the laws changed along with the times? A dishonest police officer goes missing after claiming to have information that might bring down the city's police department, and Detective Inspector Siobhan Clarke is faced with the most explosive case to hit Edinburgh in years. However, it appears that Rebus is the focus of the inquiry, and Clarke's dual loyalty to the public and the police will be put to the test.