Jean Fleury, a young engineer who has designed a revolutionary engine for the Revoil motor company, is engaged to Aimée Valois, a seamstress, his neighbor across the hall. But the charming young lady is hired one day by a nightclub and lets herself be lured by the easy life in Paris. So much so that, to Jean's great distress, she breaks up with him. But, along with time, Aimée gets tired of her vain and frivolous lifestyle and comes back to Jean.

Pierre Laurier is under the thumb of a dangerous woman. He considers committing suicide but would like to bequeath his soul to his best friend. Good people save him from death, but his friend falls prey to the bad woman. Pierre then does all he can to remove him from this evil influence. He eventually succeeds and finds serenity with a faithful and pure young girl.

The story takes place in Corsica, where a young business woman (Jacqueline Forzane) tries to construct an electric system for her steel plant. But this project is not welcomed by everyone...

Count Moffat becomes infatuated with Nana, a presumptuous stage actress, vulgar, hypocritical and promiscuous, willing to do anything to succeed.