Lu Yangfeng accepts Shangguan Xingqing's commission to infiltrate the mechanical tower and steal the blueprints for the steam core. He runs into traps and mechanical guards, then discovers by chance that the blueprints are fake and that there is a traitor within the Shangguan family. As he escapes with the false blueprints, he sees Gu Chenchen surrounded by a group of men in black, trying to kill him. After rescuing him, the two review what happened in an abandoned steam pumping station. They discover that the gear numbers on the blueprints conceal a clue pointing to a secret deep beneath Iron Furnace City.
