The yacht of millionaire Hellmann explodes in the Mediterranean Sea, with him and 8 men crew on board. Insurance agent Lucas investigates at the Cote D'Azur, because there's the suspicion that it could have been suicide. He finds out that Hellmann's villa was monitored, the tapes also contain information about the explosion. He uses them for blackmail.
Maurice Ronet
as Robert Lucas
Marthe Keller
as Angela Delpierre
Karin Dor
as Nicole Monnier
Raymond Pellegrin
as Commissaire Lacrosse
André Falcon
as Ribeyrolles
Robert Dalban
as Commissaire Principal
Walter Kohut
as Seeberg
Charlotte Kerr
as Hilde Hellmann
Eva Pflug
as Karin Lucas
Philippe Baronnet
as Alain
Alf Marholm
as Hellmann
Karl Walter Diess
as Dr. Friese
