Engineering student Petteri and retired captain Jere Renkonen arrive in Terijoki as guests of architect Matti Marras at the villa he has rented. In the midst of everything, the owner of the villa, Russian émigré prince Asatiánts, arrives with his niece Darja. Petteri eavesdrops and learns that the prince is expecting a "man from Marseille" at the villa. This man is supposed to take a secret document hidden in a large cabinet in the hall across the border to Moscow, containing information about the hiding place of the prince's family jewels.
| Actor | Role |
|---|---|
| EEnsio JoukoPrince Svjatomir Asatiánts | Prince Svjatomir Asatiánts |
| EEllen ParviainenDarja, the prince's niece | Darja, the prince's niece |
 Kerttu KrohnMiss Lily, Darja's companion | Miss Lily, Darja's companion |
 Kyösti ErämaaMatti Marras, architect | Matti Marras, architect |
 Kaarlo Angerkoskicaptain evp Jere Renkonen | captain evp Jere Renkonen |
 Leo LähteenmäkiPetteri, engineering graduate | Petteri, engineering graduate |
| LLeevi Linkovääpeli Mehto | vääpeli Mehto |
 Hugo HytönenGeneral Velikov, "the man from Marseille" | General Velikov, "the man from Marseille" |
 Toppo ElonperäPjotr | Pjotr |
| AArvo Kuuslamies Marseillesta nro. 2 | mies Marseillesta nro. 2 |