On a rainy night, eccentric tramp Mr. La Souris finds a corpse. But the body soon vanishes in his car leaving only his wallet. While the police start investigating a missing person report, La Souris concocts a plan to secure his find.

Loursat, a lawyer, lives with his daughter Nicole in a sinister and vast bourgeois residence. Abandoned for nearly twenty years by his wife, the brilliant lawyer has sunk into alcoholism and his relationship with his daughter is virtually non-existent. However, one day the corpse of a stranger is discovered in the residence of Loursat. Nicole, who frequents a gang of young people who escape boredom by stealing cars and other objects, is immediately suspected.

After the death of her husband, Christine realizes she has possibly wasted her life by marrying him instead of the man towards whom, in her youth, she had a stronger inclination. To overcome these dreary thoughts, she decides to find out about him and the other men who danced with her during a ball that was a turning point in her life, many years ago. She pays a visit to those forgotten acquaintances one after the other; Christine is not only surprised to see how they have fared, but also discovers the impact she had, unknowingly, on the feelings and the destiny of these persons.

Following a broadcast on the radio, each of the listeners remembers these "little nothings" (the title is borrowed from a play by Mozart), which have often changed their lives. Each of these stories told will prove that a tiny detail in life can change an entire destiny.

A rural maiden's two suitors go off to war, leaving her pregnant.

Outwardly, Monsieur Victor would appear to be the model citizen. A respectable Toulon shopkeeper, he has a devoted wife and is courteous and considerate to all who know him. However, beneath this veneer of respectability hides a notorious receiver of stolen goods, who trades with hardened criminals. Victor manages to keep up his double life without any difficulty until the fateful day when one of his partners in crime threatens to expose him. Fearing a scandal, Victor kills the crook in a moment of panic, using a shoemaker's tool. Naturally, the murder is blamed on a local shoemaker, who is sentenced to ten years' hard labour. Seven years later, the former shoemaker reappears in Toulon, having escaped from prison. The first person to recognise him is Monsieur Victor...