This is the third feature in a series about an intrepid French spy by the nickname of "The Gorilla," but unlike the earlier films, this time around Roger Hanin replaces Lino Ventura in the title role. A West German scientist has discovered a way to recover missiles shot into space, and the major Western powers are after his secret. Even though the scientist is willing to pass his discovery on to NATO, it is guarded by an elite, undercover West German police force. As foreign agents, including the Russians and Americans, try to get their hands on the secret, "The Gorilla" is forced into the affair by his surly, aging boss -- he has to make sure that the scientist's discovery ends up with NATO.

Valse des espions internationaux autour de la formule d'une invention secrète du savant allemand Keibel. « Ted the Hook » l'Américain, « Boris Almazian » le Soviétique, un Britannique, « Otto Lohn » l'Allemand, et bien sur Berthomieu dit « Le Vieux », chef des services d'espionnage français, se déchaîneront pour l'obtenir. Géo Paquet dit « Le Gorille » ne sera pas le moins acharné à défendre son supérieur, « Le Vieux » et les intérêts de son pays.