Down-and-out salesman Su Jin unexpectedly lands a job at the mysterious Tian Dao Company, becoming a "Doomsday Survival Solution Supplier" who travels between dimensions! His very first internship assignment sends him to a collapsing world overrun by zombies and gripped by extreme cold, where he must protect a campus beauty. Armed with a high-tech gun with unlimited ammunition and carrying a super-spacious briefcase, Su Jin launches into a campaign of bluffing and persuasion, transforming survivors among the ruins into an invincible army of superpowered fighters. Just as he sweeps away the zombie hordes, brings order to the apocalypse, and thinks he can retire after completing his mission, the system's icy notification sounds again: "Internship cleared. The New Era instance officially begins!" It turns out that Su Jin's journey as a supplier across the myriad heavens has only just begun.