Tanja Bulkova arrives in Finland under the name Toini Salonen and, with the help of spy chief Rosenberg, becomes the secretary of engineer Rautavuori and discovers the drawings of a secret invention.
The heavily indebted baron Henrik von Hagen, who loves women and partying, learns that his former lover, Russian ballerina Madame Vera Vasiljevna, will be visiting Finland. They are reunited and sparks fly. But Vasiljevna's new hobby casts a shadow over their romance.
Young heiress' spendthrift nephew turns her manor into a boarding house for the summer. Suddenly the heiress returns...
