This is the war and everybody in Germany should beware : the enemy is listening. One family in particular had better be even more careful than the average citizen of the Reich : the Kettwigs. Indeed they own an armament factory and their engineers, technicians, workers and of course themselves belong to a highly sensitive sector. They are under the constant scrutiny of those who want to get hold of the secret weapons devised in the plant, notably of a wire which, when attached to a balloon, may become the most effective anti-aircraft ever. For sure, they should distrust everybody. Isn't Nolte, the waiter, an enemy agent? Should young Bernd Kettwig allow himself to be seduced by this pretty woman ? As for Bernd's secretary, is she right when she lets this handsome man woo her?

Young Beatrice has trained as a dancer against her father's wishes. At the circus, she meets the famous tamer Ruda and falls in love with him. But the next day, Ruda disappears with the circus. Beatrice gets a new engagement with another circus and makes a career as a dancer among live tigers.