Sergeant Friman is developing an automatic submarine detector that piques the interest of both, Swedish and Russian spies.

The colonel's wife's tin pints need to be cleaned up, and Sergeant First Class Körmy tasks two privates to do so.

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.