A man with a shadowy past becomes obsessed with a female detective and starts stalking her. As she uncovers his murderous spree, which includes her boyfriend and others close to her, she is forced into a deadly showdown with him.

Following the tragic events of Sting of the Scorpion, Maggie finds herself stripped of her rank and committed to an insane asylum. The crooked cop who put her there offers to procure her release and reinstatement - if she'll go undercover as a bar hostess to spy on the triads. The whole thing's a setup, of course, and soon Maggie is on the run from the law, as well as nursing a bad heroin addiction. She finds refuge in the criminal underworld, where she accepts a job as an undercover assassin. But when her identity is exposed, Maggie has both sides of the law gunning for her life.

A group of police friends are investigating a suspicious fellow officer who might be involved in drugs and prostitution.