Four strangers are being invited to a remote castle, only to discover they are being blackmailed for their past scandals.

Two families attempt a daredevil plan to escape the GDR with a homemade hot air balloon, but it crashes just before the border. The Stasi finds traces of this attempt to escape and immediately starts investigations, while the two families are forced to build a new escape balloon. With each passing day the Stasi is closer on their heels – a nerve-wracking race against time begins.

While everything is in ruins in Berlin in the spring of 1945, the British bombers are flying overhead and the Red Army is not far away, 15-year-old Kalle is not particularly interested in doom or final victory - because he has kissed Inge Kaliska and he knows that he loves her. At this moment in world history, nothing carries as much weight as this first love.