Big Guy (Andy Lau) meets policewoman Lee Fung Yee (Cecilia Cheung), a vice cop, while the Serious Crimes Bureau is investigating an Indian murder case in the neighborhood. When Big_Lo escapes, he meets with a fleeing Indian fugitive. In the end, the fugitive escapes and Big_Lo is taken back to the police station as a suspect. In fact, Mr. Big used to be a martial arts monk in mainland China. Due to the tragic death of his friend Xiao Cui, he was overly saddened and accidentally killed a bird under a tree, and then sat in meditation with the bird for 7 days and 7 nights, thus obtaining the ability to see the cause and effect. When he sees the result, he can see the cause. He saw that Xiao Cui's death was the cause and effect, he killed the bird was the cause and effect, because he could not accept all this calmly, he returned to secularism.
This time, he saw Li Fengyi, saw the Japanese army killing people, and knew that her sins were too heavy and that she would meet with a bad fate. In order to help this kind-hearted policewoman, he began to help her secretly, helping her to solve strange cases repeatedly and saving her from danger, hoping to help her clear her sinful karma