In 1967 West Texas, Ellie Mansfield attends the Rebekah School for Girls, a Baptist reform school. Struggling with grief and a fractured sense of reality, Ellie forms an unlikely bond with her charismatic roommate, Brenna Darby. When Brenna proposes that they steal a 1966 Mustang and escape, Ellie reluctantly joins her on a journey across Texas to see the ocean for the first time. Along the way, Ellie is also forced to reconcile with her estranged older sister.