Micheline, who fled to Paris with the man she is in love with, finds herself on her own when he abandons her. She lands in a reformatory from which she manages to escape.

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.