Thirty years after the apocalypse began, Source Crystals fell from the sky and monsters ran rampant. Humanity retreated to seven base cities, struggling to survive behind steel walls.
Fortress City, humanity's last stronghold in the Far East. The elite families of Upper City command legions of Awakened and live in decadent luxury; the poor of Lower City huddle in tin shacks, never knowing if they'll survive the next day. A foul-smelling ditch divides these two worlds.
Lu Chen crawls out of the muck of Lower City. Rated F-class, he's the laughingstock of the whole school. Shoved into a cannon-fodder scouting squad, he is surrounded by a pack of beasts on his first day outside the city. Everyone thinks he'll die, but he comes back alive. Hidden inside him is a secret no evaluator can detect: absolute Source Devouring. He absorbs and converts Source Crystals at ten times the rate of an ordinary person, with no bottleneck.
When this F-class good-for-nothing beats a C+-class heir to his knees in the arena and makes him admit defeat, the whole city is stunned.
From a cannon-fodder scouting squad to an elite academy for the Awakened; from a C-class armored beast in an abandoned chemical plant to a beast tide blotting out the sky beyond the walls; from a lowly orphan trampled underfoot to someone the military and elite families can no longer ignore, the broken-bone knife in Lu Chen's hand is slowly tearing apart the world's false order.
Behind him stands an A+-class veteran who retired over a decade ago, a master who crawled out of a mountain of corpses. Old Wei teaches him more than joint locks. He also teaches him one thing: “Risking your life and throwing it away are two different things.”
But when the beast tide swallows the walls, when the harvesters of an extraterrestrial civilization arrive, and when Lu Chen's Source Armor evolves again and again amid blood and fire, he must answer one question:
Can someone who crawled out of Lower City
Come on, come on, come on