Tom Chang (Russell Wong) is a former undercover narcotics cop who was framed for smuggling heroin and spent five years incarcerated in a Hong Kong prison.

Having lost his career, his wife (Ona Grauer), and even the legal right to see his pre-teen daughter Claire (Valerie Tian), he returns home to San Francisco to try to restore his former life.

As the series begins, they are joined at the kwoon by Trip Brady (Corey Sevier), dancer Allie Bennett (Sarah Carter), and the troubled new kid in town, Nick Reed (Drew Fuller).

Nick, by his own reckoning, is well-versed in other form of martial arts, including kung fu, karate, taekwondo, wushu, savate, and Jeet Kune Do, but was nevertheless previously a disciplinary problem in Germany and Singapore while living with his parents.

Tori's policeman father has recently been killed in the line of duty and, in the pilot episode, Tom helps the police apprehend the man responsible.