The planet inhabited by humans will be destroyed, and before that, a planet suitable for human habitation must be found. Dr. Wang on the Long Zhilin spacecraft found a way to find planets. He needed to travel to an ancient civilization to find Tie Xuan Stone, and use Tie Xuan Stone's magnetic field induction to find other planets. So the four young people traveled to the four ancient civilizations and went through many dangers to find Tie Xuanshi.
