A former village priest shot dead execution-style in a snow-covered field re-opens memories of a wartime scandal around the villages of Poissons-les-Marais and Fouillmont, when young infatuation led to a spate of coldly efficient assassinations.

But who's responsible for this particular killing? And why so long after the event?

For Inspector Lucas Rocco, it means pushing aside the veil surrounding old Resistance activities and fighting dangerous political connections to track down a deadly long-range killer with the ability to hide in open countryside.