In Pursuit of the Proper Sinner : An Inspector Lynley Novel: 9

When the body of Nicola Maiden, the daughter of a retired Scotland Yard undercover officer, is found near an unidentified body in the middle of a pre-historic stone circle in Derbyshire, Inspector Lynley is asked to lead the investigation into the deaths.

Lynley must get to the bottom of the crime without the assistance of his long-time partner Sergeant Barbara Havers following her demotion as a result of an internal investigation.

But Barbara Havers has plans of her own, and they involve the very case that Lynley is working on.