Lin Chuan guards a small supermarket, but unexpectedly discovers that the iron door of the basement warehouse connects the modern metropolis on one end and the ancient troubled times on the other. He uses medicine, grain, and refined salt in exchange for ancient jade, maneuvering around gang debt collection and exposing a ten-year black ledger in modern times, while providing relief to refugees and defending the city against enemies in ancient times. Who would have known that the iron door only has three passes left, after which he can only see and can no longer cross over. Both worlds have reached their limits, and Lin Chuan grips his final opportunity tightly, intending to settle old scores, take away his family fortune, and turn the tables against heaven.