Kim Dokja (Ahn Hyo-seop), 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 apocalyptic world of the novel suddenly becomes reality, and the novel's omnipotent hero Yu Junghyeok (Lee Min-ho) appears before Kim. As the only person who knows how to survive in this world, Kim and his companions rescue Yu Junghyeok and strive to save the world by writing his own, new ending.