In the opening scene, a flashback which is played twice more, teenage Tina is sexually attacked by her "father-in-law" (actually her elder sister's father-in-law). She succeeds in stabbing him to death before rape occurs, and the fall of the bloodied corpse is witnessed by Tina's three-year old niece (elder sister's daughter) Milky. Tina's elder sister is known only as Miss Lo, despite being a lead character. Lo evidently wanted her young daughter to grow up and have large breasts !
Tina goes to prison for ten years. Shortly after, Miss Lo becomes the mistress of a sleazy character named Fu. Miss Lo didn't mind him having a wife, but objects when she finds Fu is also knocking off her sister Tina. For this reason, among others, the three girls (Lo, Tina and Milky)
never miss an opportunity to tear strips off each other.
Into this tangled web wanders Officer Lau. His entry point is Fu reporting the disappearance of his wife. Most of the plot follows Lau's enquiries and foibles, mixed in with revelations about the three girls and Fu and his wife, and some attention to Lau's girlfriend, who is also the police coroner.