During the students ' rebellion against Nicholas the Second in Russia, Viana tries to kill the governor but it's her lover who is arrested and sent to a sinister fortress : hence the title. To help the prisoner,Vania marries the officer who commands the place. There the convicts have really a bad time, but Vania manages to communicate with her dear captive. But beware of informers.
| Directing | Marcel L'Herbier | Director |
| Writing | T.H. Robert | Story |
| Writing | Jean Anouilh | Dialogue |
| Writing | André Cerf | Screenplay |
| Writing | J.J. Thoren | Writer |
| Camera | Armand Thirard | Director of Photography |
| Editing | Roger Spiri-Mercaton | Editor |
| Camera | Louis Née | Director of Photography |
| Sound | Darius Milhaud | Original Music Composer |
| Sound | Arthur Honegger | Original Music Composer |
| Directing | Ève Francis | Assistant Director |