Shi Lei owes Tang Xiaolong money. In The Knockout's story, the money owed by Shi Lei to Tang Xiaolong has never been paid off, and the interest is getting higher and higher. Shi Lei was arrested in a gambling operation. Finally, after Tang Xiaolong was released on bail, Shi Lei was released. On the way home, Tang Xiaolong stopped him and owed him a new debt. The cash confiscated by the police was returned to him by Shi Lei. Shi Lei said he really had no money. Tang Xiaolong used a fake ID card to make him donate blood twice in a row, forcing him to pay tribute again.