Shen Yan, a modern military equipment quality inspector, opens his eyes and finds himself transmigrated into the Great Yin frontier's weapons bureau, where he is a lowly sword inspector.
A dead end from the start: three thousand defective swords are due to be sent to the frontier army, and the supervising official is forcing him to stamp them as approved. If he does, the soldiers will pay with their lives. If he refuses, he'll lose his head on the spot.
At this life-or-death moment, the ancestral jade pen in his hand speaks. It's a sweet, adorable young woman who calls him "Yan'er" as soon as she opens her mouth:
[Heavenly Works Inspection Office, on duty. Everything that passes through your hands must be stamped if it passes inspection, or marked with a red X if it fails.]
Others see only the spectacle; he sees the flaws at a glance: these swords will chip after three strikes because they weren't tempered enough, that wall will collapse as soon as summer arrives because corners were cut, and a third of the silver in these falsified accounts has found its way into whose pockets?
The supervising official sneers: "You're just a sword inspector. You dare say the bureau's swords don't pass inspection?"
Shen Yan picks up a "qualified sword" and brings it down. With a clang, its edge chips and curls. The entire courtyard falls silent. He stamps the three scarlet characters for "failed inspection" on the approval ledger with a slap.
From inspecting swords to overseeing the inspection of all the empire's works, he sets standards, tracks down defective weapons, protects the frontier army, and roots out corruption. If a sword fails inspection, it goes back for rework. If a city fails inspection, it gets torn down and rebuilt. Until he draws a red X beside the dragon throne in the Golden Hall.
