Murder is always treated seriously, but when the victim is a serving copper, the killer is going to find the whole London force on their tail - and there will be no let up until they're caught. Colleagues say PC Peter Bentley was a quiet bloke who kept himself to himself. But as Slider and Atherton dig deeper, it becomes clear that this likeable bobby had secrets. Was he involved in something that got out of control or had something from his past come back to bite him?