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.

Hyun-Soo is an aspiring drama series writer. She uses “Jane” as her username and begins chatting with username “Chakhan Seupeu” (‘Good Soup’) online. “Chakhan Seupeu” is actually Jung-Sun. He dreams…