Beneath the Dragon Ball, there was a stone box which Ling Tianyu hastily picked up. He returned the Dragon Ball to its original spot and opened the stone box to find, indeed, a key inside—it was hexagonal, the key for opening the mechanized door.
"Made of crystal stone!" Ling Tianyu, looking at the hexagonal key in his hands, was extremely surprised. Keys made from this type of stone were rare.
He picked up the Dragon Ball again and placed the stone box back in its original spot, since without it, a space would form beneath it. If water were to erode this space, the position of the Dragon Ball would drop, essentially meaning a shift in position, and the treasure spot of Dragon's Pearl Cave would be ruined.
After placing the stone slab back, Ling Tianyu returned to the entrance.
