The story focuses on siblings Nina, Jay, Hud, and Kit, dealing with their famous but absent father Mick Riva. Throughout the day, long-kept secrets about Mick's infidelity, illegitimate children, and broken promises surface, testing the siblings' relationships.

Through flashbacks between the 80s and earlier times, the story reveals Mick and Eva's love story, their rise to fame, and their marriage's dissolution, showing how deeply the past influences the present and how parental decisions impact their children's lives.

Each Riva sibling struggles with their identity: Nina with the pressure of holding the family together, Jay seeking recognition through sports, and Hud wrestling with feelings for his sister-in-law. The party becomes a catalyst for confronting their demons and making life-changing decisions.