The Scarlet Virus "Red Fog" has swept across the world, and the once prosperous cities have become ruins where mutated creatures are rampant. Under the dark red sky, human civilization is crumbling.
Gu Fan, an enhancer who survived the apocalypse, accidentally activated the "Ark", an underground fortress left over from the old era, and partnered with the artificial intelligence Apocalypse. This impenetrable fortress is not only a safe haven for the 12 survivors, but also hides the key clue to ending the virus - the vaccine prototype.
In order to protect his companions and find hope for a cure, Gu Fan embarked on a desperate journey of survival: going deep into the ruins to rescue survivors, fighting to the death with terrifying creatures such as giant mutants and scaly tyrants; building a machinery manufacturing workshop to mass-produce "Hunting Blade" combat robots, "Bee Eye" reconnaissance robots and unmanned combat vehicles, and forming a doomsday mechanical division; cracking the secrets of the old era leaked by the virus, and discovering that vaccine development requires the integration of three cores: ice crystal grass, black jade ore and the serum of semi-infected people.
However, crises ensued: vaccine experiments triggered deadly mutated antibodies, and the fortress faced an internal infection crisis; the mysterious "Black Crow Base" raided with heavy machinery troops, intending to snatch virus research results; traces of semi-infected people were hidden in dangerous abandoned industrial areas, and murderous threats lurked on the road ahead.
In the collision between human nature and interests, and the confrontation between machines and mutant creatures, Gu Fan led the survivors to use the Ark Fortress as the foundation to fight against the doomsday with courage and technology. Can they gather the vaccine materials to end the virus? Can we repel the pretenders and keep mankind's last hope? Under the rust-colored sky, an epic story about survival, struggle, and civilization reconstruction is slowly unfolding on the ruins.
