At the street corner of the old city of Jiangzhou, there is a water delivery worker named Chen Haisheng, who has carried water and climbed stairs for three years, arriving as soon as anyone calls for help with anything. No one knows that he enlisted at the age of seventeen and spent twelve years in the reconnaissance company, and even less knows that his return to Jiangzhou is to find out the truth about his old squad leader's death in a car accident twelve years ago. On a stormy night, he handed an umbrella and blocked people for Hengsheng President Jiang Manli, taking on a five-million contract to guard her business. Delivering water, checking accounts, overturning old cases, step by step he ferreted out the killer hidden inside Hengsheng. On the day the accounts were settled, he pedaled his tricycle back to the street corner and hung up his sign.