Plainclothes policeman Lao Zhang (played by Zhang Lixian) drank happily with a group of brothers at the wine table, and sang out the bitterness, sweetness, sourness and spiciness of Beijing. They lurked in the endless stream of people, waiting for an opportunity to catch criminals: whether they used electronic interference with car locks to steal property, or used disabled people as bait to touch porcelain, whether they were gangsters, or fortune tellers who were swaggering... none of them could escape Lao Zhang's eyes. Lao Zhang's deeds were even on the documentary of Beijing TV. However, seeing the criminals being arrested one by one, Lao Zhang's heart fell into confusion. He is also an ordinary person with old parents and young children. After years of hard work, Lao Zhang's body also lit up red lights. He has asthma and high blood pressure, but in order to catch thieves, he tried hard to overcome his difficulties. However, there is always a follower at his door, and many bizarre events happen one after another, catching Lao Zhang and his brothers off guard... This film is adapted from the true deeds of Zhang Huiling, a police officer of Shuangyushu Police Station of Haidian Branch, Beijing. This film is part of Gao Qunshu's "You" Series: 1930-2030, and about 30 Weibo celebrities such as Zhang Lixian, Kong Ergou, Wang Xiaoshan, Zuoyeben, and Ning Caishen have joined.