Ted Kennedy's life and political career become derailed in the aftermath of a fatal car accident in 1969 that claims the life of a young campaign strategist, Mary Jo Kopechne.

In South Boston, where Irish roots run deep and Catholic tradition reigns, two brothers face similar hardships but lead far different lives. While older brother Terry descends into drugs and crime, 16-year-old Cole vies to make the state baseball championships - but must struggle to withstand his brother's destructive influence.