Watch World War Z (2013) : Online Free. 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.