Months after the American government launches a chemical weapons attack on its own people, the remaining population has divided into two groups: (1) the themed gangs (the Gamblers, Sheets, Plowboys, Nailers, and Cherries), and (2) those who survive on their own away from the violence and gangs (the Domestics).
Domestic couple Mark and Nina West are traveling to Milwaukee to see Nina’s parents while dealing with the fallout of getting a divorce before everything happened. They meet Nathan Wood and his son when scavenging supplies and go to their house for a meal but it ends in chaos after they discover Nathan’s family fed them human meat. A Nailer Mark believed he killed earlier finds them and kills Nathan’s wife and daughter.
They escape and retreat to an abandoned house after Nina is shot, unaware they’ve been followed by a deserter Cherry named Betsy who escaped Plowboy captivity and has developed a fascination for Nina. Mark is later held at gunpoint By William Cunningham; a flamboyant madman and forced to fight against a large opponent after he discovers William has beaten and captured Nathan and his son who followed Mark for revenge. Mark wins and Nathan departs, forgiving him and giving up his quest for vengeance.
Mark reunites with Nina who finds an old car similar to what Mark once owned and the two rekindle their love but are then captured by Gamblers. They’re forced into a Russian roulette game with Mark taking a bullet. Nina makes her escape after grabbing a gun from a Gambler’s boot, finally making it to her parents house.
Nina learns her parents had died, Mark discovers her father’s prized Wildey Hunter is stolen and the Gamblers have caught up to them. A showdown begins with Nina, Mark, Betsy, the Gamblers and Plowboys. In the end Nina and Mark survive, Betsy returns Nina’s ring to Mark before being killed, and Nina finds her father’s gun at a neighbors home who was a Gambler spy.
Mark and Nina leave ending with Crazy Al; a DJ who has been sending broadcast updates about the current America.