Seo Mi-rae is worn out by work. Love? It's the last thing on her mind. But a virtual dating service sparks feelings — and maybe a real shot at romance.

Jae-yoon, a late military enlistee, and his girlfriend, Young-joo, break up over the phone over growing misunderstandings. But a zombie outbreak rocks the world. A national emergency is declared, a plane crashes in the city center, and Jae-yoon and his unit get trapped on top of a Seoul skyscraper. Young-joo risks the zombie-filled streets to find him. Can their love survive the apocalypse?

Kim Dok-ja, an ordinary man in his 20s, is the only reader of an obscure web novel titled "Three Ways to Survive the Apocalypse". After having read the last chapter, the novel suddenly becomes reality, and its omnipotent hero Yu Jung-hyeok appears before Kim. As the only person who knows how to survive in this world, Kim and his companions strive to save the world by writing his own, new ending.

In 1987, bloodied man Soo-ho jumps into a women's university dormitory in Seoul. Yeong-ro, a female student who fell in love with him at a group blind date, tends to his wounds as the dormitory is ensnared in intense surveillance. As Soo-ho's secrets unravel, he must eventually face the conflict between his heart to Yeong-ro and responsibility to his comrades, as well as to his sibling who awaits him in his home country. What will be of their fate?