In Malibu in 1983, the four Riva siblings—Nina, Jay, Hud, and Kit—host Nina’s famous annual end-of-summer party. Behind the glamour, each of them carries emotional wounds linked to their absent, famous father and a troubled family past. As the night unfolds, long-hidden secrets come to light and tensions rise. The party spirals out of control, ending in a devastating fire that destroys their home. In the aftermath, the siblings are forced to confront their past and begin rebuilding their lives.