A black-clad figure breaks into the Jade Dragon Shipping Company at Los Angeles Harbor. In the office of the president, vice president Raymond Ling brings owner Adam Chung tea. He tells his superior that MacGyver and Pete Thornton will be arriving late, and hopes that they can help find out who is trying to buy out Jade Dragon. After he leaves, the intruder climbs down the side of the building and fires a crossbow bolt through the window at Adam. Adam ducks just in time and the explosion destroys much of the office. As the security forces mobilize, the intruder slips under a passing lift. Once outside, the driver, Wayne Lin, tells the intruder she's on her own. The woman removes her clothing to reveal a swimsuit underneath. She slips over the side of the dock and swims away.
Pete and MacGyver go to the hospital where Raymond warns that Adam isn't doing. Pete explains that the Foundation has learned that a Hong Kong criminal cartel is trying to obtain Jade Dragon so they can use it to ship illegal goods across the world. Chung is the sole owner and his death will leave the company open to a buyout. Chung asks to talk to Pete and MacGyver alone, and then informs them that he has one previously unknown heir: a grandson, Luke who is now 14 years old. He only wishes Luke to take control of the company if the boy wants to. He tells them they can find Luke at a monastery outside of San Francisco.
MacGyver goes to the monastery and meets with Luke. He suspects that Luke, having led a sheltered life, isn't ready for the responsibilities of owning a company. However, Luke insists on seeing his grandfather. They go to the hospital only to discover that Adam has slipped into a coma. An intern, Steve, witnesses Luke's arrival and calls his superior, Alasdair. Alasdair is the Los Angeles representative of the Hong Kong cartel, as is Raymond Ling. Raymond had no idea that Adam had a grandson. Alasdair tells Raymond to have Wayne and his men kill the boy and make it look like a mugging.
That night, Luke uses jher-jun acupuncture to help improve Adams' condition. As they go to the parking garage, Wayne and his men attack them, Wayne using a wrench. MacGyver fends off some of them using a metal pipe and Luke easily defeats the rest using his martial arts techniques.
Raymond gets word that Chung is recovering thanks to Luke's treatment. He plans to have Steve the orderly secretly poison Chung. When Steve refuses to commit murder, Raymond calls in Tiu to force Steve to go through with the plan. Once the orderly is gone, Tiu says that since Wayne failed, she plans to personally eliminate Luke.
Luke returns to his grandfather's side and Adam explains that he sent Luke to the monastery when his father died. Adam blames himself for not giving Luke more of a life but Luke insists that his grandfather owes him nothing. When visiting hours are over, Luke returns to his grandfather's manor. Meanwhile, MacGyver and Pete search Adam's office for any clues. Looking outside, MacGyver spots a worker using the same wrench that Wayne attacked with in the parking garage. He figures that Wayne worked there and checks the records. They find an employee whose description matches Wayne's, who quit just after the attempt on Adam's life.
Tiu visits Adam's manor and claims to be a friend of the family. She has a get-well gift for Adam: a pair of lovebirds in a musical cage. Luke invites her in once security checks her over.
Checking the records, Pete learns that Wayne came from Hong Kong in the company of a young woman. He somehow got a job immediately with Jade Dragon despite having no credentials. Pete checks on who hired the man while MacGyver goes to see Luke.
Tiu and Luke talk about Luke's life and she notes that he hasn't seen all the poverty and misery in the world. He realizes that she's been hurt in the past but Tiu brushes over his remark. When Luke goes to get tea, Tiu activates a dart-firing mechanism in the birdcage. Luke returns and Tiu makes her excuses and then leaves. As she drives away, MacGyver arrives and spots her, and remembers the fact Wayne came into the country with a woman. He runs inside while Luke turns on the musical mechanism on the birdcage. MacGyver runs in and yanks Luke to the floor as darts fire in all directions. As Luke recovers, MacGyver notices that Tiu left her purse. He opens itï¿½ and a cobra rears up. Luke throws one of the darts and kills the snake.
MacGyver and Luke are called to the hospital where Adam is getting worse. They arrive only to be informed that Luke's grandfather has passed away. Luke examines the body and then states that Adam was poisoned.
Luke goes back to his grandfather's manor and performs a ceremony. MacGyver arrives at the house as Pete brings in more security men. The police have found Steve, dead, and figure he poisoned Adam. According to the coroner, the poison was a rare substance that wouldn't have been detected if Luke hadn't told them about it. They go inside and discover that Luke has slipped away. They examine the statue he was using in his ceremony and realize that Luke was performing a vengeance ritual. MacGyver figures that Luke will try to track the poison ingredient through shops in Chinatown and goes to find him.
Alasdair has learned that Luke is still alive. He slaps an angry Tiu for failing him, and then comes up with a new plan. Now he wants Luke to sign Jade Dragon over to him.
MacGyver finds Luke at an apothecary and warns him how dangerous it is to be out on his own. Luke agrees to come with him but Raymond and Tiu arrive and capture them. They lock them up in the cellar of an old Chinatown shop. MacGyver examines their surroundings and finds boards written with a Chinese plea for protection. He explains that Chinese laborers dug escape tunnels throughout the city, and then takes apart an old-fashioned console radio and uses the loudspeakers as makeshift sonar projectors. He finds a hollow spot in the walls, but hides the speakers when Alasdair comes down to talk to them. Alasdair tells Luke to sell over Jade Dragon, but when the boy refuses, MacGyver asks for a few minutes to convince him.
Once Alasdair and the others are gone, MacGyver and Luke get the escape tunnel open. MacGyver shorts out the lights and they proceed down the tunnel to a long-abandoned opium lab with a waterfall and leftover equipment. MacGyver has Luke rip apart pieces of opium packing paper and create a framework of wooden struts. He then covers the paper with mud and soot from a stove.
Alasdair, Raymond, and Tiu return to the cellar and quickly find the escape tunnel. They go down the tunnel and enter the room, only to discover that no one is there. Tiu spots MacGyver's Swiss Army knife beneath the waterfall and calls Raymond over. MacGyver and Luke, hiding behind a fake paper wall, jump out and knock them unconscious. Alasdair opens fire and the duo duck for cover. Luke uses the bellows for the stove to blow ash into Alasdair's face. Blinded, the cartel head quickly goes down.
Later, Luke is ready to take over Jade Dragon and has put on a suit and tie. Pete assures him that the Foundation will back whatever he says, and Luke insists that he plans to let his conscience be his guide.