Leading chemist Hans Schramm is betrothed to Hanna, but falls in love with her younger sister Franka. The two attempt to repress their feelings, but eventually begin an affair. When Hans is extorted by a group of West German agents, who demand to know about his secret work, he is gripped by panic and decides the only way out is to flee to the West …

Ce synopsis est en anglais : nous ne l'avons pas encore traduit.