In the middle of the night, Cai Mingyu, a member of the government's secret service, enters the chongming dungeon with a message from Longyan Island. He wants to find out the identity of the man who killed all the demons in the previous night's raid on the house. He also wants to know if the man is the one who killed the merman in the earlier raid. The two men enter the dungeon together, and Cai tells him that he must follow the rules of the secret service since he works for the government.