L'Alpagueur is a free-lance spy from the French secret agency. He's put on the investigation about L'epervier, a serial-killer who employs young boys to help him robbing banks before killing them.

Jean-Paul Belmondo
as Roger Pilard, aka l'Alpagueur

Bruno Cremer
as Gilbert, aka l'Epervier

Jean Négroni
as Spitzer

Patrick Fierry
as Costa Valdez

Jean-Pierre Jorris
as Salicetti

Victor Garrivier
as Doumecq

Claude Brosset
as Granier

Marcel Imhoff
as Director of cabinet

Maurice Auzel
as Road driver 'Gros Bras'

Muriel Belmondo
as First flight attendant