Netherworld Pearl 1

Boom, a loud noise woke up Cheng Gang who was sleeping. Cheng Gang looked out the window and saw a large hole with a faint green light emitting from it. Cheng Gang walked out of the door and walked into the hole. Cheng Gang saw a bead and thought that this was the thing that gave off the green light in the hole. Cheng Gang felt very strange, where did this bead come from, who did it belong to, and how could it come to earth?