Jen, nicknamed Ah Dai, had been a rebellious child. He fled home the age of 16. A few years later, he became the driver of the leader of the Underworld, Mr. Lin. He was deeply moved by the kindness and care Mr. & Mrs. Lin showed him, grateful enough to do anything for them in return. Ah Dai observed the conflicts and struggle for privileges in the Underworld, and its strange interactions with the police. To evade the law, Mr. Lin fled abroad with his mistress as a wanted criminal. During Lin's absence, Ah Dai witnessed the crumbling of Lin's empire. Because of Ah Dai's loyalty or his sympathy with her, Mrs. Lin becomes attached to Ah Dai and eventually has his baby. However, when Mr. Lin comes back later to save his empire, Mrs. Lin chooses to give up her relationship with Ad Dai. As a way of repaying kindness, or even of showing his love, Ah Dai sacrifices his life to finish the last task Mrs. Lin asked him to do.