MacGyver is returning home after a hockey game and passing through the Little Haiti district. In a nearby shop, Sergeant Concassuer is threatening the owner, Denise. He demands payment in return for protection and Denise reluctantly gives in. However, her niece Cherine arrives and tells Concassuer to get out before she calls the police. MacGyver notices the commotion and comes in, and Concassuer backs down. However, he warns Cherine that he'll bring Baron Samedi to meet her the next time he pays the shop a visit. Cherine leaves for a protest rally but Concassuer and his thugs grab her. They drive away, almost running over MacGyver when he tries to stop them. Denise notices a voudon doll that Concassuer has dropped and quickly picks it up.
Sergeant Rudley arrives to take Denise's statement about the abduction. She refuses to identify Concassuer despite the fact she knows who he is. MacGyver talks with Rudley, who warns him that it's the third abduction in the neighborhood but everyone is too intimidated to testify. After the police leave, MacGyver asks Denise what's going on, and she explains that Concassuer is with the Tonton Macoute, the former secret police in Haiti. Concassuer and his men have moved to Little Haiti and are using their criminal skills and connections to take over the neighborhood, and they left the voudon doll as a warning.
MacGyver goes to see Mama Lorraine and shows her the voudon doll. Mama Lorraine explains that Concassuer is performing sacrilege and focusing only on the evil of voudon, while she treats with both sides evil. She tells MacGyver that Concassuer has placed a curse on Cherine and suggests he talk to Dr. Pierre Redemteur, Cherine's professor at the university. They meet with Redemteur, who explains that Cherine has been protesting the Haitian dictatorship and Concassuer wants to silence her. MacGyver mentions Concassuer talking about Baron Samedi and Redemteur explains that Samedi is the loa of the graveyard, and controls the unliving. Concassuer is adapting the religion for his own ends and uses a drug that can induce a coma state to create persons who appears to be zombies. Redemteur admits that some of his own students have joined Concassuer's cult.
Concassuer brings Cherine to Colonel Devraux, the head of the local Tonton Macoute operation. When she defies him insists he's corrupting the voudon religion, Devraux insists that he's merely helping to bring peace to his people and then blows a powder into her face. Cherine collapses, falling into a coma.
MacGyver and Mama Lorraine return to her shop and examine the doll. While Mama Lorraine points out the plant that can provide an antidote to the zombie drug, MacGyver finds oily dirt inside and realizes that it came from a dried out riverbed. The oil is turbine oil, and MacGyver deduces that it came from the riverbed near the old Liberty. He and Mama Lorraine go there and spot Concassuer holding a voudon ceremony in broad daylight. The worshippers are gathered around Cherine, who has been placed in a coffin. Mama Lorraine explains that the drug induces a deathlike coma, leaving the victim conscious but paralyzed, and that Cherine will only live a few hours without the antidote.
Mama Lorraine joins with the worshippers and distracts the guard so that MacGyver can sneak into the tunnels beneath the dam. He meets Mama Lorraine inside and she goes to join the ceremony while MacGyver looks for Cherine. She enters the main chamber and Concassuer greets her. He's glad to have her there and hopes that they can convince her to lend her authority to their voudon ceremony. Devraux, dressed as Baron Samedi, enters the chambers and calls upon the worshippers to support Papa Doc and turn against his enemies. He brings out Cherine, still in the coffin, and says that he will bring her back as his zombie servant.
As the opening ceremony concludes and the stage curtain closes, MacGyver approaches Cherine and tries to revive her. Outside, Concassuer suggests that Mama Lorraine join them but she refuses, and he warns her that refusal could be dangerous. She leaves and goes backstage to find MacGyver, but Concassuer and Devraux find them both. Devraux blows more powder into MacGyver's face. He collapses and Mama Lorraine tells him to slow his breathing and avoid panic, which will only spread the drug faster. Devraux boasts that nothing she can do will help MacGyver and offers to cure MacGyver if Mama Lorraine will join forces with him. Mama Lorraine agrees and secretly gives MacGyver an herb to keep resist the drug a little longer.
Devraux's men take Mama Lorraine to his chamber while MacGyver is placed in a crude wooden coffin. As they take the coffin away, MacGyver bites into the herb and revives a bit. As the van bounces down a country road, MacGyver manages to pull a rope through a knothole. As the van bounces, the coffin slides back and forth until the rope pulls taut and yanks the side off the coffin. MacGyver pounds on the back of the cab and the two men stop and come to investigate. MacGyver knocks them out and drives back to Mama Lorraine's shop. He takes some of the plant that has the cure and turns to find that Dr. Redemteur has entered the shop. He draws a gun and tells MacGyver that Devraux sent him to recover the voudon doll. He explains that he's working with the colonel and used his position as a professor to recruit students. He's also used his knowledge of chemistry to help Devraux create his drug. As Redemteur warns that MacGyver's recovery is only temporary and he'll need full hospitalization, MacGyver grabs some of Mama Lorraine's flash powder and uses it to distract Redemteur and knock him out.
As Mama Lorraine stalls for time, MacGyver returns to the dam. He drops the voudon doll behind the guard at the gate and drops on the man to knock him out. He goes inside and rigs some oil drums on a brick, using the wiring from a circuit box to tie the brick to a gate.
Mama Lorraine takes the stage and begins reviving Cherine to demonstrate Devraux's voudon power, while Devraux prepares to make his entrance through a secret trapdoor in the basement. MacGyver finds him and knocks him out. Concassuer begins to wonder when Devraux doesn't make his entrance on time and sends his man to investigate. MacGyver, dressed as Baron Samedi, uses Devraux's flash powder igniter to make his own entrance and then denounces Concassuer as a traitor to voudon. When Concassuer and his men head for the stage, MacGyver activates the flash again, grabs Mama Lorraine and the recovered Cherine, and they go down into the basement. They flee through the tunnels and get to the gate. MacGyver pulls on the wire, releasing the brick and causing the oil drums to roll back and slam into Concassuer and his men as they follow.
Later, MacGyver gets the necessary treatment at the hospital and meets with Mama Lorraine. She assures him that Cherine will recover and be able to testify at Devraux's trial. MacGyver admits that he still doesn't believe in magic, but wants to learn more about her religion. Mama Lorraine assures him that she has interceded on his behalf, and convinced the loa that because he's a vegetarian, he doesn't need to sacrifice a goat to make amends.