A summary of a summer adventure.

Juanjuan, who studied judo in Beijing Sports School, also returned to her hometown during the holiday and helped in the "Juanjuan Fast Food Restaurant" opened by her parents. While visiting Tallinn, "foreigners" and "tycoons" met the "heroes" who went up the mountain for martial arts in the summer vacation. The three of them hit it off and went hand in hand. In the evening, when they were camping in the street, they happened to meet a primary school student who ran away from home. Because he loves to cry, the "foreigner" nicknamed him "Cry Win" and agreed to take him on a trip. "Cry Win" was overjoyed and took them to an old warehouse to settle down. The next day, the children were worried because they lost their wallets and couldn't fill their stomachs. "Crying to Win" volunteered and bought four kinds of snacks from "Juanjuan Fast Food Restaurant" with two lines of tears. The next day, four children agreed to stay and watch Home, while the other three went out to work. "Cry Win" kept rummaging around in the warehouse, and suddenly found a template engraved with the national emblem and a tin box of counterfeit banknotes. Just then, the door of the library suddenly opened, and a group of people broke in, fighting for money, and suddenly blood flowed. The children were frightened and called the police. At the same time, Juanjuan's parents also reported the case to the Public Security Bureau and found counterfeit money. That night, "Cry Win" worked in a snack bar and suddenly found the murderer in the warehouse. The man also found the national emblem template hanging on his chest, and his face suddenly changed. Juanjuan learned the whole story from these four children, took them to a hotel and told them not to run around. Late at night, the murderer found the hotel and the children cleverly hid. The next day, a policewoman found the children and claimed that the murderer had been caught and asked them to testify. The children got into the van with her. On the way, the children found the female police officer dressed as a gangster, so they struggled with it and subdued it, while the cunning principal ran away. After receiving Juanjuan's report, the Public Security Bureau ordered all traffic intersections to be blocked. Finally, with the close cooperation of the children, the murderer was arrested at the railway station. The children embarked on the journey again with the joy of victory.