A young boy, with a reckless streak, raised by a poor mother in a suburb of Beijing, has a couple of scrapes with the authorities. A young detective who lives nearby takes an interest in him, takes him under his wing, and tries to mentor him. Though love blossoms for the young man, his mother dies, which forces him onto the street, and to survive, into a world of crime. With a dangerous encounter he is scared straight, escapes the drug trade, and helped by a forgiving girlfriend tries his hand at business. But his past crimes come back to haunt him, and he is forced to work undercover with the same detective who has mentored him, to thwart the burgeoning crime wave that has gripped the city.