A son of a family in debt decides to put an end to his life and calls on a professional killer to do so, who promises to kill him within forty-eight hours. However the next day, money, luck and love smile at her again. Then can begin an infernal hide-and-seek between the assassin and his victim.

Two modest young employees, Jean and Madeleine, dream of leading the way, but the experience turns out badly. Madeleine marries a German aristocrat who turns out to be a spy, and finds Jean who had joined the Legion.

The film portrays the relationship between a female Moroccan student, who has been forced to leave her studies at the Sorbonne for financial reasons and works as a dancer in a Paris nightclub, and a French naval officer. However, on returning to Casablanca she is tricked into believing that he had the led attack on her village that wiped out her family. She begins to plot her revenge.

Willy Ferrière is a gambler living beyond his means, and his mistress is as greedy as he's dead broke. One day, he says out of loud in a a Montparnasse café that he would give 100,000 francs to get rid of his wealthy aunt so he could claim his inheritance. Someone secretly lets Willy know it's a deal. The old lady is murdered, and a low-life criminal is manipulated to be the perfect suspect. But Superintendant Maigret feels something is wrong.