Relations between Sweden and Finland come to near breaking point. When further negotiations led by President Mara fail, Sergeant Körmy interferes in the course of events.

Uuno Turhapuro's younger brother Peni arrives in Helsinki. Uuno helps his brother in management duties.

Detective Karisto releases Auno 'Räpsy' Pirilä from prison, who in turn has to calve his childhood friend Börje from criminal activities. Alcoholic Dolly takes Räpsy to live in Kallio, Helsinki, and hopes to move to Paris with her in the spring.