Isidore Lechat is a ruthless self-made man whose money allows him to humiliate the others, particularly a ruined noble: he wants his daughter to marry this marquis's son but the girl is in love with a young scientist.
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.
Catherine's technique to sell her clocks is to blackmail illegitimate couples such as Jacques and Gisèle. However when Gisèle's husband Pierre walks in on them, Catherine pretends to be Jacques's lover to save the day. Jacques then gets caught up in her schemes when the next couple she deals with turn out to be jewel thieves who kidnap them.
