Episode 13 recap: The lunar device of the Hate Tian Department.

Hu Ba Yi carefully observed the rocks at the end of the path. He suspected that the area blocked by the rocks was likely the exit, and that the rock collapse had effectively blocked the way out. Unable to move the rocks, they continued searching the surrounding area. Not far from the suspected exit, they discovered a very large wooden beam, which stood there like a tower with several thick iron chains hanging around it.

Hu Ba Yi noticed that the shape of the large wooden beam looked familiar. He called Gu Cai over, who had a pattern on his back. According to Gu Cai, he had this pattern since he could remember, and he referred to it as the "Translucent Sea Map." Hu Ba Yi's guess was correct. In the center of the Translucent Sea Map, there was a cylindrical object that indeed resembled this large wooden beam. In ancient legends, the wooden beam was used for traveling to the moon. Therefore, Hu Ba Yi suspected that this large wooden beam likely extended all the way to the sea surface. To confirm his theory, Hu Ba Yi planned to climb up and take a look. Gu Cai volunteered to accompany him. However, even after both of them climbed to the top of the tree, they couldn't find an exit.

While descending from the large wooden beam, Gu Cai accidentally stepped on nothing and fell from above. Luckily, there was a platform not far from where he fell, and Gu Cai was caught by the platform. Gu Cai stood up, rubbing his sore body, and unexpectedly found a door on the platform. He called Hu Ba Yi over, and together, they pushed open the door. Inside the door, they discovered that the body of the large wooden beam had been hollowed out. Near the edge close to the inner mirror, there was even a downward staircase. The two of them returned to the base of the tree and had everyone climb up together, then they descended down the staircase.

Fatty, due to his fear of heights, hesitated to climb for a long time. It was only after Duo Ling persuaded him that he mustered up the courage to climb up. However, on the way down, he ended up wetting his pants out of fear. When everyone reached the base of the large wooden beam, Da Li made fun of Fatty for this incident. Fatty, unwilling to mention this embarrassing moment in front of Duo Ling, became angry and pointed his gun at Da Li, demanding that he take back his words. Duo Ling watched from the side and couldn't help but laugh secretly.

Hu Ba Yi observed the surroundings and combined it with the Translucent Sea Map on Gu Cai's body. He suspected that this large wooden beam was a rocket launch system. He instructed everyone to search for the launch mechanism. While searching, Da Li was startled by a female corpse. Shirley Yang went over to investigate and found something resembling a baby inside the corpse's belly. She felt that it was related to the launch and handed it over to Hu Ba Yi.

They couldn't find the launch system as the large wooden beam extended deep into the sea. Hu Ba Yi suspected that the launch system might be at the very bottom of the large wooden beam. Therefore, he put on a diving suit and, together with Gu Cai and Fatty, went underwater to search.