A prominent politician is murdered during a demonstration. The government and army are trying to suppress the truth. But, a tenacious magistrate is determined to not to let them get away with it.

Yves Montand
as Z

Irene Papas
as Hélène

Jean-Louis Trintignant
as Examining Magistrate

Jacques Perrin
as Photojournalist

Charles Denner
as Manuel

François Périer
as Public Prosecutor

Bernard Fresson
as Matt

Pierre Dux
as Gendarmerie General Missou

Georges Géret
as Nick

Magali Noël
as Nick's Sister