France 1942 during the occupation. Philippe Gerbier a civil engineer is one of the French Resistance`s chiefs. Given away by a traitor he is interned in a camp. He manages to escape and joins his network at Marseilles where he makes the traitor be executed... This non-spectacular movie (do not expect any Rambo or Robin Hood) shows us rigorously and austerely the everyday of the French Resistants : their solitude their fears their relationships the arrests the forwarding of orders and their carrying out... Both writer Joseph Kessel and co-writer and director Jean-Pierre Melville belonged to this "Army in the Shadows".