D/S Jimmy Suttle is called to the scene of a brutal murder in the picturesque Devon village of Lympstone. Harriet Reilly, a local GP, has been found disembowelled in the bedroom of her partner, climate scientist Alois Bentner, who has since disappeared. Meanwhile, Suttle's estranged wife Lizzie has abandoned Portsmouth, moved to Exeter and returned to journalism, hearing rumours of a local GP offering mercy killings to patients meeting certain criteria. The name of the GP is Harriet Reilly. So begin two investigations of the same crime: Operation Buzzard, with D/S Suttle at its heart; and Lizzie, piecing together her own version of the events that led to the death of the enigmatic GP.