Robert and Françoise Monier make a hot air balloon to fly to the stratosphere. After a visit to Venus, they return home, but have only aged 15 days whereas 25 years have passed on Earth.
Blondine, the daughter of a poor fisherman, marries the Prince of the Mountain. Brune, her sister, envies Blondine her happiness and tells her that a secret lies hidden in her husband's name. Blondine tries to discover it but, before she does, the Prince is imprisoned by an ogre. Blondine must face goblins, imps, and the water djinni before she can deliver her captive Prince.
A young woman has doubts about her husband's fidelity. She pretends a trip, but settles in a hotel where her husband must pass. He meets her and, disturbed by the one he believes to be his wife's double, becomes her lover. Little by little the truth breaks through. The husband takes leave of the mistress and returns to the wife whose return has been announced.
