Jack Kane is an unorthodox Houston cop out to stop a yuppie criminal gang known as the “White Boys” that has stolen a large quantity of heroin from a police warehouse. But the arrest turns rapidly to a massacre when a strange individual comes from nowhere and slaughts the criminals before escaping with the drug.
Reluctantly partnered with FBI agent Laurence Smith, Kane begins to inquire on the strange circumstances of this slaughter. The two policemen discover the arm of the crime, a weapon out of the common, a little circular disc that does not cease to function until it is attracted by a magnet and that systematically throws on each alive being, guided by the electrical signals that they release. On the other hand, a series of death by massive heroin overdose touches indeed a population that does not drug habitually. All the victims show the same puncture wounds to the forehead.
Meanwhile, the guy who stole the heroin from the " White Boys " continues his misdeeds; Endowed with instruments allthemore strange as hisweapons, he injects overdoses of drugs to his victims in order that the former secret the endorphin that he is going to extract from their brains. Helped by his jurist friend Diane, Jack quickly understands that the pumped substance represents a priceless intergalactic drug for a man coming from outer space.
But Jack and Laurence are not the only people who want to stop the alien dealer schemes. This one is also pursued by another alien, police force representative, who tracks him up to Earth. Unfortunately he fails in his quest after having warned the two policemen against the arrival of hundred other "dealers" if they do not stop him.
Spoiler ! the end of the story is revealed below…
But the FBI knows the situation and wants to catch the alien for the purpose to exploit the technological values he represents for the army. Despite their deliberated intentions but veins to fire the inquirers and to forget the affair, the federals cannot prevent the Houston’s cop and the FBI agent to fly to the pursuit of the monster…
Laurence, newly owner of the powerfull pistol of the alien police forces, and Jack launch in persisted track. Jack succeed in confiscating to the creature his phial of endorphins he extracted. After having escaped them, the monster who wishes to recuperate his junk, quickly finds them back. This is only after a long fight that Jack will get rid of the dealer by means of his own weapon coming from the stars.
Each time the alien dealer prepares to kill a new victim, he says « I come in Peace ».