During an otherwise placid Thursday morning commute, human civilization deconstructed itself like a riot in a madhouse, one hand-to-hand death-brawl at a time. None escaped the slaughter. Perversely efficient in the aftermath, an alien-incepted Terminus Signal drives roving clans of homicidal lunatics to exterminate these Immunes to a last number.
During the course of their apocalyptic odyssey, one such band of desperate survivors must overcome petty, pre-Terminus differences to form life-and-death bonds strong enough to withstand the actual end of their world. While fighting for their lives, this hastily assembled family will ultimately uncover the sinister truth of Terminus, and then they must confront and somehow overcome the horrific realities of global extinction as they undertake Simian's Walk.