At three o'clock in the morning, Chen Fangyuan pushed the dead electric scooter for two kilometers. A voice message came from his five-year-old daughter Youyou on his mobile phone: "Dad, the iron egg knocked down Jasmine again." He smiled bitterly and said that he would wait for his father to go back and repair it. I dropped out of 985 five years ago. Now I am wearing fluorescent yellow delivery clothes. I am stopped outside the community by security guards and scolded by customers for overtime complaints. Liu Ming, an auto mechanic in the shared house, handed him a cigarette and asked him if he could bear it. Chen Fangyuan shook his head, but he dug out the four-stroke engine tuning method from the knowledge base and helped Liu Ming solve the problem at the modification shop. The next day when he was delivering food, he encountered an old man who had fainted. The knowledge base suggested first aid procedures, so he rushed forward to perform cardiopulmonary compressions to save his life. The video was posted online, and some people mocked the delivery man for showing off. He didn't defend himself and went back to the rental house to cook noodles for Youyou. The iron egg jumped onto his knees and the second jasmine flower finally bloomed. But life will not let anyone go easily - Youyou's physical examination report for kindergarten admission turned red, his ex-girlfriend Zhou Rong suddenly appeared to fight for custody, and staying up late to deliver meals for a long time made his heart start to alarm. Facing the invisible walls of this city, what can a delivery father with only knowledge and no resources do to protect his Jasmine and cat?