On a stormy night, Yuxuan awakens a metal-based ability at a convenience store and escapes Ningcheng's zombie horde with Su Li, a healer. They battle steel worms, build a gear fortress, and overcome deadly predicaments like a rust-corrupted city puppet master and a water crisis. He also uncovers the connection between his parents and an underground Qinling space station, unlocks the evolution of his abilities, and faces a choice involving the Star-Slayer weapon.
Then twelve giant towers appear, mechanical wyverns launch an assault, and the Star Gate opens. The story moves into the sea of stars: Yuxuan lands on Liming Star, fights energy-absorbing crystal beasts, allies with native mechanical beings, and builds a starship to repel raiders. He infiltrates the Interstellar Federation to expose a "mechanical ascension" conspiracy, then explores the ruins of an ancient metallic civilization and obtains the universe-level power of the Metal Origin.
The intergalactic Gold-Eaters invade. Yuxuan leads the allied forces to battle at the edge of a black hole, while Su Li destroys the enemy's nest with an antimatter core. But Yuxuan is gravely wounded and falls into a deep sleep. When he awakens, he faces the ultimate crisis of "cosmic rust." He and Su Li merge their two cores to become a "cosmic metal symbiote." Together, they unite civilizations to build an Origin Array, stop the rust, and establish a new order. Their daughter, Yu Yue, who has a metal-prophecy ability, also grows into a protector.
At last, an "outer-realm rift" appears at the edge of the universe. The couple leaves behind the "Liming Legacy" and faces the danger side by side, vowing that "Dawn will never end" and leaving readers with a stunning cliffhanger.
