A likeable young man, reduced to living by expediency, is launched in spite of himself into an adventure of stealing jewels. With the help of a brave, rough-looking but actually very clear-sighted policeman, the jewels are recovered, the stolen young woman is reassured and the main culprit is forced into exile.

Monsieur Fred is a friendly Southerner who recruits pretty girls down on their luck to send to South America. After some dramatic incidents and an eventful chase, a policeman manages to lock up the gang he runs.

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.