Five friends are released from prison and do their best to stay out trouble. While trying to mind their own business (and run their 5-Star Cleaning Service), they are caught up in a war between rival Triad gangs fighting for control of the counterfeit currency market.

To save the Hong Kong Police Force's Banshee Squad from becoming defunct, the struggling new squad members seek the help of former officers Amy (Sandra Ng), now a divorced mom with a young kid, and May (Kara Hui), now partially mentally-unstable, to help them with their training regiment, lead by Madame Yang (Cynthia Khan). Their police skills are put to the test when they are ordered to nab a band of brutal thugs in the city.