An NYPD cop is 'killed' in an accident. The death is faked, and he is inducted into the organization CURE, dedicated to preserving the constitution by working outside of it. Remo is to become the enforcement wing (assassin) of CURE, and learns an ancient Korean martial art from Chiun, the Master of Sinanju. Based on the popular pulp series "The Destroyer," by Richard Sapir and Warren Murphy.
A cop who answers a call is ambushed. The next day he is buried. But in reality he is in a hospital and his appearance has been altered. He is then told by a man named McCleary that he now belongs to "them". "Them" being CURE an organization whose job is to battle corruption. They give him the new name of Remo Williams. He then meets the head of CURE Harold Smith, who spends most of his time sitting in front of a copmuter and perusing over reports of individuals that have to be dealt with. They then give him to Chiun, a Shinanju master, which is the art of killing someone and making it seem like an accident or natural causes. Chiun's regimen is hard on him. Smith then discovers a man named Grove, who is a defense contractor. It seems that whenever there's a case against him, the key witnesses and investigators disappear. Currently a military investigator is pursuing him about his new project which for some reason, he is tight lipped about. Smith sends McCleary and Remo to help her but Grove discovers them and wanting to know about them decides to stir things up. He sends some people to take Remo out but he outwits them. And when he tells Smith about it, Smith doesn't care who then tells him that unless they have more evidence against Grove they can't do anything and if they are about to be exposed, they have to disappear. And while Smith and McCleary have made arrangements for their demise, Remo is told that Chiun will take him out. So he and McCleary have to get the evidence they need.
An officially "dead" cop is trained to become an extraordinarily unique assassin in service of the US president.
- Sam Macon (Fred Ward) is an NYPD cop. One night, he breaks up a mugging, and then is pushed into the river in his car.
Sometime later, he awakes in a hospital, with a new face. MacCleary (J.A. Preston) tells him his new name is Remo Williams (based on a name on a bedpan), and that Remo now works for an organization that doesn't officially exist. MacCleary says Remo is ideal because he has no family and has military background. Remo steals an ambulance, but Mac is in it. He takes Remo to meet Harold Smith (Wilford Brimley), the head of the organization CURE.
Smith tells Remo that the government is corrupt, and Remo will be their troubleshooter. Smith has computer access to all networks, and Mac is his liaison. Mac takes Remo to a building and tells him to kill the man inside. Remo slips in and find an elderly Korean man, but no one else. He realizes the Korean is his target and tries to kill him, but he's too fast. The man is Chiun, and is his trainer.
Smith researches George Grove (Charles Cioffi), a defense contractor with criminal suspicions, especially on the HARP defense system. He notices someone trying to access the same information - Major Rayner Fleming (Kate Mulgrew). She tells her boss, General Scott Watson (George Coe), and reminds him that she will be attending a weapons demonstration by Grove.
Remo begins his training. Chiun is rude and harsh, insulting Remo at every turn. However, Remo gradually comes along. They work on balance and breathing, and mutual respect begins to develop, although Chiun won't admit it. Remo gets good enough to dodge bullets and run without leaving tracks.
The Grove weapons demonstration shows grave flaws with the weapons. Fleming gets suspicious. Grove tells General Watson to bury the report. Grove defends himself when asked about HARP, mentioning the CD-18 demonstration planned for the following week at Mount Promise. Grove gets annoyed with Fleming, and asks Stone (Patrick Kilpatrick) to trail her. Stone gets photos of Fleming, Remo and Mac, and Grove orders him to kill Remo. Remo notices Stone's diamond dental work, too. Remo uses his new skills to defeat the bad guys atop the Statue of Liberty, but Stone gets away. Remo complains to Smith and Mac, and they tell him they all have an escape plan - Remo's is death by Chiun. He's obviously angered by the news, and walks out on Chiun.
Mac and Remo infiltrate a Grove warehouse, battling extremely clever dogs and ravenous rats. Remo finds a satellite, which is subsequently destroyed by lasers, alerting the guards. They escape, but Mac is shot in the back. Mac gives Remo a computer disk for Smith to analyze, and is captured, but commits suicide before telling Grove any information. Smith realizes HARP is a fake and tells Remo to go after Grove. He meets Fleming at Mount Promise, and they get locked in a steel gas chamber by Wilson (Michael Pataki), one of Grove's goons. Remo fights Stone and uses Stone's diamond tooth to cut the glass to escape.
During their escape from the facility, they find Chiun and steal a truck with no brakes. Remo and Fleming jump out, but Chiun cannot open the door. He's dazed, but otherwise unhurt, and inadvertently calls Remo "my son". Remo continues his mission, calling Chiun "little father".
The military chase Remo and starts firing at him. Remo rides a tree trunk being pulled through the woods on cable. He drops the log and overturns the jeep with Grove and Watson, then races to the lake to escape. He dodges bullets fired by Grove and disarms him. He tosses Grove on the Jeep and lights in on fire, walking away. Chiun is surrounded by troops and walks across the lake to safety. Remo tells Fleming, "we're the good guys".