A group of teenage boys compete in an annual contest known as "The Long Walk," where they must maintain a certain walking speed or get shot.

Twenty years ago, a series of tragic events almost ripped the blue-collar town of Millwood apart. Now, in the present day, a group of disparate teen girls finds themselves tormented by an unknown Assailant and made to pay for the secret sin their parents committed two decades ago, as well as their own.