How, thanks to what's known as the "Butterfly theory" (a random series of unlinked events), can a young woman and a young man meet?

On election night in 1981, celebrations spill out onto the street and there is an air of hope and change throughout Paris. But for Elisabeth, her marriage is coming to an end and she will now have to support herself and her two teenage children. She finds work at a late-night radio show and encounters a troubled teenager named Talulah whom she invites into her home.