Seven years after the tragic death of her brother Donnie, Samantha Darko is still mourning him and the loss of the loving family that fell apart after he died. Her home life in shambles, 18-year-old Sam impulsively decides to join her rebellious best friend Corey on a cross-country drive from Virginia to California in the hope of becoming a professional dancer.

When their car breaks down outside tiny Conejo Springs, Sam and Corey are stranded in the hot and dusty town with little money and no connections as they await the arrival of a new water pump. Wild child Corey quickly finds a friend in Randy Holt, the town bad boy, but Samantha is restless and has no interest in socializing.