An investigation into the nature, details and reasons for the collaboration, from 1940 to 1944, during World War II, between the Vichy regime, established in the south of France and headed by Marshal Pétain, and Nazi Germany.

Marcel Ophuls' riveting film details the heinous legacy of the Gestapo head dubbed "The Butcher of Lyon." Responsible for over 4,000 deaths in occupied France during World War II, Barbie would escape—with U.S. help—to South America in 1951, where he lived until a global manhunt led to his 1983 arrest and subsequent trial.