Lieutenant Ville Somero investigates a sabotage at a fortress site on the Karelian Isthmus in the summer of 1939. His suspicions are directed at the guests of a nearby guesthouse. Aarno Teräs an engineer leading the fortification site, and his bride Birgit Lahti get into trouble because of a band of spies and dancer Veronica Sorrento.
| Actor | Role |
|---|---|
 Matti LehteläVille Somero | Ville Somero |
 Dolly von AlfthanVeronica Sorrento | Veronica Sorrento |
| EEnsio JoukoKausalainen | Kausalainen |
| AAarno KivistöAarno Teräs | Aarno Teräs |
| AAnna-Liisa SarvantoBirgit Lahti | Birgit Lahti |
 Verna PiponiusMs. Lindström | Ms. Lindström |
 Sven RelanderSuhonen | Suhonen |
| AAune HämeMrs. Berg | Mrs. Berg |
| RRunar SchaumanMaximov | Maximov |
| EEero LeväluomaTuomi | Tuomi |
 Vilho SiivolaLimppunaama | Limppunaama |
| EErkki UotilaKarvonen | Karvonen |
| JJoel AsikainenNot listed | Not listed |
 Kerttu SalmiNot listed | Not listed |
| EEino HaavistoNot listed | Not listed |
| OOiva TurunenNot listed | Not listed |
| UUrho VirtaNot listed | Not listed |
 Pentti SaaresNot listed | Not listed |
 Armand LohikoskiNot listed | Not listed |