Pumpkin, the last girl on earth and sole survivor of a humanity-ending plague, scavenges the wasteland for supplies on the eve of Halloween. Pumpkin’s lonely holiday ritual is interrupted by the arrival of a savage gang of raiders at her doorstep, led by the fearsome Thalia. Outnumbered and armed with candy, wit and weapons, Pumpkin must ferociously fight back to survive the night.

Caleb, a former government assassin in hiding, who resurfaces when his protégé, the equally deadly killer known as Banshee, discovers a bounty has been placed on Caleb's head.