A cop suffering from "posterior ulcers" tries to catch a serial killer who seeks out victims with medical problems. One suspect is a man who makes pies from guts, which the cop inadvertantly eats. Eventually the hero cop finds himself tied to an operating table with the killer preparing to deal with his "posterior ulcers"!
| Actor | Role |
|---|---|
 James Yi LuiLei | Lei |
 Margaret LeeMargaret | Margaret |
| LLee Din-HingMrs. Chu | Mrs. Chu |
 Chang Kuo-ChuDr. Chu | Dr. Chu |
 Lawrence Cheng Tan-ShuiKiang | Kiang |
 Chan Lap-BanLei's Mother | Lei's Mother |
 Hon KongMortuary Staff Member | Mortuary Staff Member |
 Eric Yeung Jan-YiuCoroner Tse | Coroner Tse |
 Philip Chan Yan-KinOfficer Chan | Officer Chan |
 Dion LamOn | On |
 Pak Man-BiuKiang's Father | Kiang's Father |
| CChan Fung-ChiAuntie Fung | Auntie Fung |
 Sai Gwa-PauTaxi driver | Taxi driver |