During Scenario 1 on the subway train, the system demands that passengers kill a living organism within a set time limit. While panicked citizens turn on each other, Dok-ja uses his knowledge of the novel to take grasshoppers from young Lee Gilyoung’s collection box and kill them instead, fulfilling the scenario rule without murdering humans and saving his immediate companions.
When Dok-ja meets the legendary regressor Yoo Joong-hyuk on the damaged Dongho Bridge, Joong-hyuk tests Dok-ja's claims of knowing the future by dropping him off the bridge into the mouth of an Ichthyosaur (sea monster). Instead of dying, Dok-ja uses his text knowledge to survive inside the monster's stomach, form a contract with the Dokkaebi Bihyung, and establish his own stream channel.
As the film reaches its climax in ruined Seoul, Dok-ja unites Yoo Sang-ah, Jung Hee-won, Lee Hyun-sung, and Lee Gilyoung to clear high-tier scenarios that previously killed Joong-hyuk's team in original timelines. By defeating the area's calamity boss through tactical loopholes, Dok-ja successfully breaks the original tragic storyline. The ending leaves Joong-hyuk convinced to team up with Dok-ja rather than resetting the timeline, setting up their journey to alter the remaining apocalyptic scenarios together.