Zhang Xiaohua's idea was correct, as long as your divine powers were sufficient, you could indeed see the origin of that extremely thin black mist. However, the "sufficient divine power" was a realm that Zhang Xiaohua could never have imagined. The black mist was coming from an unknown place underground, appearing abruptly above the platform. Clearly, it did not follow an ordinary underground path, it was not as Zhang Xiaohua currently assumed, the place through which he passed daily using Earth Escape. It was just that this platform, as tall as a person, blocked Zhang Xiaohua's field of vision, and also restricted his train of thought.
Moreover, the strange thing on the platform also made him misunderstand the use of the platform. He thought that this platform was there to block the black mist, but in reality, the true purpose of the platform was just to elevate the height, allowing the black bead to perfectly block the place where the black mist surged from!
