In the aftermath of an unknown catastrophe, a community left with zero living adults has descended into a modern-day Lord of the Flies, run by a small cabal of what had been the jocks occupying the athletic and social upper crust of the local high school, headed by Caleb (Patrick Schwarzenegger).

Faced with the bleak despair of their situation, Josh (Jacob Lofland) and Jessie (Sophie Kennedy Clark) strike out on a dangerous journey into the unknown to find family and hope for the future, with Caleb and his vicious underling Gentry (James Bloor) in hot pursuit.