Hu Bayi and Fatty Wang had planned to go abroad with Shirley Yang. However, they were entrusted by Professor Chen to travel to the Coral Spiral with Mr. Ming to search for the Qin Emperor's Bone Mirror. They befriended Ruan Hei, Gucai, and Duoling on Coral Temple Island. Together, they set sail. One night, they were sucked into the underwater cave of Guixu. In despair, Hu Bayi and Shirley Yang decided to risk their lives using the Sun-shooting wooden mechanism to lead everyone out of Guixu.