Kim Dokja, a 28-year-old ordinary office worker, has spent the last decade as the sole reader of a web novel titled Three Ways to Survive the Apocalypse. As he finishes the final chapter, the world around him abruptly transforms into the novel’s reality. Monsters appear, the sky tears open, and a mysterious being called a dokkaebi announces the start of the first main scenario: a deadly game where humans must kill another living creature to survive.

While others panic, Dokja realizes his unique advantage. He alone has read the entire 3,149-chapter story, memorizing every character, every disaster, and the ultimate ending of this world. Armed with this knowledge, he sets out to survive and rewrite the story, beginning with his first encounter with Yoo Joonghyuk, the original protagonist of the novel. Joonghyuk is a regressor who has lived through this apocalypse countless times, growing stronger and more detached with each regression.

The story follows Kim Dokja as he gathers allies, including his coworker Yoo Sangah, the former soldier Lee Hyunsung, the young insect collector Lee Gilyoung, and the vengeful Jung Heewon. He also encounters Han Sooyoung, a writer who holds her own secrets about the creation of the novel itself. Together, they form Kim Dokja's Company, a nebula that challenges the established order of the Star Stream.

The setting is a post-apocalyptic Seoul, but the world expands far beyond Korea. The Star Stream is the governing system, a universe-wide broadcasting network where powerful beings known as Constellations watch humanity's struggles as entertainment. Constellations are deified versions of historical and mythical figures such as the Demon-like Judge of Fire Uriel, the Prisoner of the Golden Headband Sun Wukong, and the Queen of the Darkest Spring Persephone. They sponsor incarnations, sending coins and skills in exchange for entertainment. The scenarios progress through numbered stages, each more difficult and cruel than the last, transporting survivors to locations ranging from the Korean Peninsula to the Demon Realm and the Underworld.

Notable narrative arcs include the initial scenarios in the Seoul subway, the confrontation with the King of a Kingless World at Myeongdong Station, the disaster of floods brought by the monstrous creature Shin Yoosung, and the journey into the Underworld where Dokja becomes the adopted son of Hades and Persephone. Later arcs explore the 73rd Demon King scenario, the war against the great constellations in Gigantomachia, the Journey to the West remake, and the final scenarios that reveal the true nature of the Star Stream and the identity of the Oldest Dream, the being who dreams the entire world into existence.

The story examines themes of perspective, stories as sustenance, and the relationship between a reader and the text. Kim Dokja, the reader, learns that his knowledge is not absolute and that the characters he thought he knew have depths beyond their written descriptions. Yoo Joonghyuk, the protagonist, confronts the meaning of his endless regressions. Han Sooyoung, the author, faces the consequences of creating a world of suffering. The narrative builds toward an epilogue that redefines who is saving whom, as Kim Dokja's Company works to retrieve their reader from the edge of existence.