"You should know about the complicated relationship between humans and the Celestials." Donnie's expression was exceedingly grave. Stephen nodded and said in a deep voice, "I've been closely monitoring outer space, guarding against them." "That's not enough. The most troublesome ones aren't the Celestials from outside, but the thing beneath our feet." Donnie shook his head and stomped lightly on the ground. "Four billion years ago, a mysterious Celestial that had gone mad died on Earth. That was how life appeared on Earth.