Humanity has all but perished in a tidal wave of lethal violence, overwhelmed by a mysterious disease that drives its victims mad. Thrown together in the chaos, Will and Jesse, a white New York financial manager and a young black man struggling to make ends meet, flee the carnage in search of safety. But safe no longer exists in a world where monsters stalk the land in human skins and the sane must kill to protect themselves. Death haunts cities and towns, farms and fields, even remote mountainsides. Yet life endures in unlikely places, and as Will and Jesse confront their new world and themselves, a glimmer of hope emerges. For they've picked up an unlikely pair of companions, an old scientist and a brilliant teenage girl. Together, the quartet might stand a chance but for one thing: the old man swings between sanity and madness, and as civilization struggles to reemerge, they must hide his condition...and the terrible truth behind it.