On December 12, 1969, a bomb kills 17 people at the Piazza Fontana national bank in Milan, Italy, marking the beginning of the Years of Lead. Local anarchists are scapegoated for the massacre by police and the media, but a lone prosecutor uncovers a conspiracy of far-right groups, corrupt secret services, and other interests that seek to undermine democracy.

Don Matteo is a thoroughly ordinary Catholic priest with an extraordinary ability to read people and solve crimes. He’s a parish priest who never met an unjustly accused person he didn’t want to help.