Part 3/9:
After fighting off a zombie, Clay realizes the shocking correlation: those who had been using their phones have mutated into the undead. In chaos, airport guards arrive but misfire amidst the pandemonium. Clay narrowly escapes an aviation disaster that sees crashing planes set the airport ablaze, leading him underground with fellow survivors. Joining forces with a train conductor named Tom, they traverse dark subway tunnels to evade the relentless zombie horde.