A warship returning from a training exercise was tasked with apprehending an unknown schooner that had violated GDR territorial waters. Although nothing illegal was found during the search of the ship, the ship's commander Fischer was suspicious of the owner of the schooner, Arendt, a former lieutenant of a Nazi coastal battery. Fischer's doubts were confirmed when a diver came aboard the schooner and photographed a military object underwater. The investigation showed that the detained schooner was on a sabotage mission, and the "activities" of Arendt, a former Gestapo Obersturmführer, were also revealed.
Hans-Peter Minetti
as Lieutenant Fischer
Rolf Ludwig
as Oberleutnant Arendt
Horst Kube
as Private Lutz
Wilhelm Koch-Hooge
as Petersen
Werner Lierck
as Sergeant Kohl
Fritz Diez
as Lieutenant Wegner
Günther Grabbert
as Oberleutnant Hermann
Albert Zahn
as Soldier Thielicke
Dieter Perlwitz
as Jens Dahl
Katharina Matz
as Ike
Gustav Püttjer
as Ole
Manfred Borges
as Sergeant Schneider
