[36] The film focuses on the aftermath of an unreported beating meted out by a PTU column on a person in a back alley that was caught on a camera placed by the tourism bureau.
It follows Fai, as he is physically coerced to do things by the PTU, and two rival triads, and the resultant consequences and violence that is paid in return for those actions.
[37] Human Nature focuses on the always-in-debt CID officer Tong, and his travails to try to repay the debt he owes a loanshark.
Their rivalry leads to disrupted interaction and communication when many PTU units are used in a search for a gang of criminals holed up on a forested mountain.
[44] In addition to the official entries in the series, as in Hong Kong tradition, other completely unrelated films have been given similar titles in order to take advantage of the fame and popularity surrounding PTU.