There are countless such cities in the endless fog. They have no special names, only numbers. Children living in the cities have almost never left the city before they were ten years old. On Haohao's tenth birthday, he and his classmate Li Dakun went out to explore the city. On the way, they met Zhou Miaomiao and Teacher Zhou Xing. The strange thing is that the teacher Zhou Xing in front of him is actually a robot, and the real teacher Zhou Xing has disappeared long ago. In order to find Teacher Zhou Xing, they were involved in an alien conspiracy, but the truth was far from that simple.
Purpose: Every adult has the responsibility to protect the blue sky for children.