During a shootout in a saloon, Sheriff Hunt injures a suspicious stranger. One of the villagers takes care of him in prison. One day they both disappear – only the spear of a cannibal tribe is found. Hunt and a few of his men go in search of the prisoner and his nurse.
Life for former United Nations investigator Gerry Lane and his family seems content. Suddenly, the world is plagued by a mysterious infection turning whole human populations into rampaging mindless zombies. After barely escaping the chaos, Lane is persuaded to go on a mission to investigate this disease. What follows is a perilous trek around the world where Lane must brave horrific dangers and long odds to find answers before human civilization falls.