Commissaire Perrache, the chief of the D.S.T., the French domestic intelligence service, tries to neutralize a group of terrorists named the Partisans de la Métropole. He sends one of his best agents, inspector Louis Vignon, incidentally the husband of his charming secretary Lucette, on the trail of an illegal transmitter. But Vignon gets kidnapped by the gang and held captive on a boat off the shores of Monaco...

Charles Vanel
Commissioner Perrache of the D.S.T.

Anne Vernon
Lucette Vignon

Jacques Morel
Inspector Paul Duchamp

Maurice Teynac
Kurt Topfer

Henri Crémieux
Saab Astérich

Yves Massard
Inspector Louis Vignon

Robert Porte
Koskah

Marcelle Arnold
Lynda
Berthe Tissen
Mrs. Astérich

Edmond Ardisson
Linda
Roger Bontemps
Naval officer

Jean-Paul Coquelin
Technician from South Tunisian

René Havard
Technician from South Tunisian

Germaine de France
Mrs. Perrache

André Numès
Archivist