Master Kung and Lo Pa are two police officers of White Horse City, who have high skills but are underused. A robbery happened at he city's richest man Ho Pak Man's home where his whole family was killed and their family treasure the "White Jade Goddess of Mercy" was stolen and the "Police God" Tit Mo Ching investigates the case. Kung and Lo Pa cannot participate because of their low status. Coincidentally, Master Kung and Lo Pa arrest a pair of twin sisters, Water Dragon Girl and Fire Dragon Girl, who always pretend to catch wanted criminals to get monetary rewards. The twin sisters know that the "White Jade Goddess of Mercy" would be brought to the "Treasure Inn" for an auction. Wanting to hit big, Master Kung and Lo Pa go to the "Treasure Inn" with the twin sisters to investigate the truth. During that time, Master Kung and Water Dragon Girl become lovers from a kiss.