 Arvid Pettersson (Stefan Ekman) works as a customs officer in Haparanda in 1916. This is a time when the small town, being a border town on the Swedish side of the border between neutral Sweden and Finland, then belonging to czarist Russia, currently involved in World War I, is a center for soldiers, refugees, smugglers and spies. He discovers that a Russian ballerina, who s on her way to perform in Stockholm, has a gun, but he doesn t report it, since he falls in love with her a little. However, this isn t the biggest trouble he has because soon afterward, he and two other Swedes (Ernst-Hugo Järegård and Hans Ernback) become accused of the murder of a Russian V.I.P. in Torneå, on the Russian side of the border. They manage to escape from Russian prison and an almost certain sentence to the feared Peter Paul s prison in Petrograd (former St. Petersburg). As they discover that the ballerina has something to do with the murder, they start following her towards Stockholm. However, they are still on the run from the Russian and now also Swedish police, who think they re behind the murder. Their chase for the murderer takes them both to Stockholm, Skåne (Scania) and even Copenhagen. And all the time, they have the police on their heels.