Citizens from upscale Gangnam in Seoul start experiencing unusual and terrifying symptoms, devolving into inhuman creatures, leaving only a few survivors with the possibility to make it out alive.

Yoona has managed to mature into a fine woman despite her rough childhood. One day, when Yoona finds out that her mother has become ill, she travels home for the…

A-Ra (Ha Na-Kyung) works at a real estate office as the director. She also has clandestine meetings with some of her male customers for fun. Meanwhile, Mi-Yeon (Kwak Hyun-Hwa) begins…