In Dallas, a man is found dead in a vacant lot. With no leads, witnesses or motive, lead Det. Rick Duggan and his team must put the pieces of the case together to find their killer. And in Minneapolis, Sgt. Gerhard Wehr and Sgt. Jerry Wallerich are working one of the most brutal crimes of their careers–the violent stabbings of a mother and her 10-year-old son.