Gu Changan, an apprentice at Blackwood City's blacksmith shop, has a secret. He suffers from a strange disease - he always wants to eat iron, and the iron he eats can make him see something "wrong" in the world.
In his eyes, everything is no longer a complete whole, but a mess of sketches, full of messy lines and flaws. He originally thought that he would be surrounded by fires and iron filings for the rest of his life, relying on this craft to earn a living.
Until that day, a dying guest brought a strange piece of meteorite that "couldn't be knocked, smashed, or melted."
When Gu Changan accidentally took his first bite, what he tasted was the aftertaste of broken stars and the lamentation of an "existence" imprisoned outside the laws of heaven and earth.
From that day on, the "lines" of the world began to converge towards him, and all the immortals, gods, princes and generals were eyeing this humble blacksmith.
They want the secrets in him, the piece of "sky" he swallowed.
Gu Changan wiped the rust from the corner of his mouth and weighed the hammer in his hand.
"Want to steal food from my mouth? Okay, first ask me if the hammer with forty years of skill will agree."
