Uuno Turhapuro's younger brother Peni arrives in Helsinki. Uuno helps his brother in management duties.
The Minister of Defence asks sergeant Körmy to take part in operation, where the United States and Russia are to hand over their nuclear weapons launch equipment and codes to neutral Finland.
New takeover plans and Russian art thief looking for Mannerheim's portraits keep Sergeant Körmy busy.
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.
