As a widowed father, Yue Sui Bo (Anthony Wong) lived his life as a Chinese chiropractor. His kids Nicky (Stephen Fung), a dolphin trainer at Ocean Park and Natalie (Gillian Chung), a high school student, learn martial arts from their father, but were unconvinced of their father's claim to a secret life as a heroic body guard for retired agents. When the father tries to provide too much and the kids are tired of all the bragging, the family is not going to be a harmonious one.

Until one day, Rocco (Michael Wong) arrives in his wheelchair, asking Teddy for information on ex-agent Dragon. Knowing that Dragon interrupted Rocco's mission twelve years ago which cost Rocco his legs, Teddy's lips are sealed. Rocco leaves in silence but four kungfu experts return and successfully capture Teddy after an almost even fight. Drugged and tortured, Teddy finally reveals that the data of the retired agents is hidden in his kids' lucky charms.