Life seems perfect in Valley Farm, a quiet community in Northumberland. Until a shocking discovery. The owners of a big country house have employed a young ecologist named Patrick to look after the place while they're away. But Patrick is found dead by the side of the lane into the valley.
DI Vera Stanhope arrives on the scene with her colleagues. When they look round the attic of the house - where Patrick has a flat - she finds a second body. All the two victims have in common is a fascination with moths.
As Vera is drawn into the claustrophobic world of this increasingly strange community, she realises that there may be deadly secrets trapped here