Rosine, who spends her time as a model, has to deal with the advances of a disreputable young man.

The inhabitants of a small provincial town are requisitioned to take part in the French army's major maneuvers. A foreign spy takes advantage of these maneuvers to steal secret documents. The pursuit and capture of the spy and his accomplices are successfully carried out by all those taking part in the maneuvers.

From Constantinople to Marseilles, aboard a cargo ship, an intrigue full of adventures brings together a courageous young girl and a young risk-taker who succeeds in thwarting a series of long-planned crimes.