Delphine is a passionate 25-year-old swimmer living in the provincial French town of Montélimar. She shares a stable, dependent domestic life with her partner, Laurent, residing under the roof of his hostile, cold father, Norbert, while she trains for her official swim coach diploma. Her predictable world is entirely upended when she meets David, a charismatic outsider who instantly falls for her and arranges a job transfer to town just to be near her. Torn by conflicting desires, Delphine plunges into a passionate, secretive extramarital affair. The domestic arrangement becomes a ticking emotional time bomb when she discovers she is pregnant with Laurent’s child, while Laurent turns to drug dealing to escape his father's financial control. Ultimately, the web of hidden infidelity and domestic strain collapses when the disapproving patriarch discovers the pregnancy and evicts the young couple from his home.