Shaolin Priest and widower Kwai Chang Caine raises his son Peter in the monastery learning the same lessons he himself learned as a child. During a training session with older and more experienced pupils, Caine learns the priest providing the guidance and lessons is completely distorting these holy teachings so he calls him out on it, which spurs a fight between the two men that ends with Caine exiling the priest from the temple although before he leaves, the priest swears he will take his revenge against Caine, his son, the temple, and the temple inhabitants.
Sometime after the priest's exile, he returns to the temple where he destroys it with explosives then demolishes it with fire. In the scramble for safety, Caine and his son each believes the other is dead. Caine swears he will, "walk the earth," searching for his son's spirit and soul as it was reincarnated.
Peter is taken to an orphanage in a large city where he is later found by Paul Baisdell and his family including his wife Annie. Over the course of 15 years, Peter grows into a kind man who believes in justice and helping others. In order to put his skills and beliefs to work, he joins the police academy where he works his way up to police detective using the lessons he can recall from his days at the monastery.
By an amazing twist of fate, Caine comes to the city where Peter is a detective. Whether it is destiny, fate, or simple blind lucky, the two attempt a rocky yet promising family connection as father and son.