During the summer vacation of the junior year, the female protagonist and the male protagonist were in a bad mood due to emotional quarrels, so they made an appointment with their best friends Chen Xi and Tan Caicai, and took a plane to Xishuangbanna, Yunnan Province to travel and relax. Wandering into the unknown world and losing contact with the outside world...... The male protagonist couldn't contact the female protagonist at first, thinking that the female protagonist was angry with her, and ignored him for a while. But with one day, two days, and three days passing..... the male protagonist is still ...... It's impossible to contact the heroine, the mobile phone can't be unplugged, the message is sent, and there is no reply. The male protagonist learned from Chen Xi's sister Chen Xiaomei that they went to Yunnan. immediately went to his girlfriend's house, and his girlfriend's father, Su Yifang, a university professor, could not contact his daughter and had already called the police. Then Chen Xi's family, boyfriend Pan Zhixiong, and Tan Caicai's brother Tan Datong found the male protagonist. But a day passed, and the result reported by the police was: the three people were lost near the village, and their whereabouts were unknown! Everyone began to feel that the matter was serious, and after discussion, it was decided that the male protagonist, Pan Zhixiong and Tan Datong would fly to find them that night, and Chen Xiaomei clamored to go with them. They refused, on the grounds that it was inconvenient for a little girl to follow three big men, and perhaps they needed to take care of them, dragging their feet. However, Chen Xiaomei hid from her parents, bought a ticket and flew to Yunnan, and the four of them began a journey to find their lover or relatives...... What did the male protagonist encounter in the unknown world?