Chen Jin was treated as a humanoid weapon by the military, but the parasitic black symbiote in his body began to bite back the host. When he devoured seven guards and tore apart genetic chains in the laboratory of blood and iron, he discovered that he was not the first—nor the last. Scientist Lin Xiao was observing in the dark, Anvil was gathering the remaining soldiers in the ruins, Su Yue's betrayal was tearing open the cracks in the truth, and the monster called the 'Patriarch' was staring at him with his sister's eyes. Symbiotes are not weapons, they are keys. And the key will eventually open the door to hell.