In The Knockout's play, Gao Qisheng wanted to do PHS business, so his classmates introduced Gong Kaijiang, King Cao's father, to Gao Qisheng from Jinghai. Gao Qiqiang and Gao Qi invited Gong Kaijiang to dinner. So King Cao is Gong Kaijiang's son.

"The Knockout" tells the story of a 20-year life-and-death struggle between the righteous forces and the evil forces represented by An Xin, a frontline policeman.