Marguerite Le Goff has a sad destiny. Daughter-mother to a holidaymaker at the age of sixteen, she tried to earn a living in Nantes, but succumbed to the promises of the disreputable Pierre who had found her in a sailors' box. Deprived of her child, what would she do if good people didn't sympathize and her childhood friend Jean-Marie didn't take her with him?
A gangster, thief of atomic formulas, has a double in the person of a naive musician. A music hall artist who makes eyes at the musician is deceived by the gangster who also takes advantage of the resemblance to track down a band of thugs who are chasing him. Virtue is ultimately rewarded.