The movie opens with titles and credits shown over a woman and a voodoo doll. She places a noose around the thing's neck and cinches it tight.
Tonda Metz (Allison Hayes) walks over to the bedroom window to spy on her husband, Dr. Carl Metz (John Wengraf). He is relaxing out on the porch. Tonda tightens the noose on the doll and Carl begins to choke. He calls for the houseboy, Suba (Dean Fredericks, as Norman Frederic). Metz asks for water, but it does not help. Suba enters the house, and Tonda puts the doll away. Tonda calls for Suba. Her husband outside returns to normal. Suba confronts Tonda. She inquires about her husband and is told the doctor is sick. Sporting a large dagger on her belt, Tonda goes out on the covered porch to see her husband. She feigns concern then tells her husband she wants to go off for a walk in the jungle. Before she leaves they hear drums. Suba translates and tells the doctor and his wife that three white men approach and will arrive shortly. One man is ill and needs the services of a doctor. Metz loudly objects to their visit and wants them stopped, but Tonda tries to intervene. Suba still departs to carry out the doctor's orders.
Four men approach the doctor's house. The guide, Gogi (Paul Thompson) leads, followed by two men carrying a third on a stretcher. Suba fires at the group with his rifle. Tom Maxwell (Paul Burke) demands the firing stop. Tonda orders Suba to stop. She approaches the group and asks their intentions. When told of their need for a doctor, Tonda directs them to the house. Metz invites them inside, Gogi remains outside. While Dr. Metz cuts away the injured man's shirt, Norman (Joel Marston) looks on. Joe (Robert Christopher) was mauled by a lion and is near death. Metz dismisses Tom and Norm to an outside hut so he can begin treatment on Joe.
Tom exits the hut and talks to Gogi. Gogi is terrified by the sight of a vulture feather imbedded in the hut. Tom pulls the feather out, over Gogi's objections, and drops it on the ground. Gogi sees it as a very bad omen. Using a shovel, he picks the feather up and drops it into the fire. Tom goes off for a walk and encounters Tonda on the porch of the house. She hikes up her dress to show a little more thigh and calls to Tom to join her. Suba watches and listens to the pair converse. She makes subtle signs of interest in Tom, who quickly dismisses himself. Tonda accuses Suba of spying on her. Suba threatens to tell Dr. Metz about his wife. She embraces Suba, kisses him, then just as suddenly slaps him. Suba's wife, Mara (Eugenia Paul) strolls by and sees the seduction and rejection of her husband. Tonda walks slowly back into the house. With tears in her eyes, Mara retreats back into the jungle. Tonda enters Joe's room with a skull and some bones. She places three bones on the man's chest, then burns a section of his shirt. Suba exits his hut in a trance-like state.
In a jungle clearing, a native ceremony is underway. In the center, around a fire, Tonda dances. She is surrounded by dancing natives. Suba is on an altar, sporting a squiggly line down his chest. Norm wakes Tom to listen to the ceremony. They walk over to investigate. They take Gogi along, over his objections. They witness the ceremony from under cover. The dancing and music stop and a dead chicken is thrown to Tondas feet. Tonda picks it up by the feet and walks over to the altar. The three men leave before the ceremony concludes. Tonda throws the chicken on Subas chest as he shakes with fear. Using her dagger, Tonda approaches a doll and stabs it. Joe, back at the house, grimaces in pain.
The next morning, Norm and Tom enter the house to check on their friend's condition. The house appears to be empty, so Tom goes to check on Joe. He is shocked to see Joe's wounds almost completely healed. Tom calls Norm in to see Joe. Dr. Metz comes into Joe's room to check on his patient. He appears to be just as surprised as Tom and Norm at Joe's remarkable recovery. Dr. Metz tries to explain the quick healing as attributable to special jungle plants, but Tom and Norm are not quite sold. A scream outside draws the pair out of Joe's room and to a native hut nearby. Mara accuses Dr. Metz of murder and vows revenge. Dr. Metz slaps the hysterical widow. Tonda takes Mara in the house to comfort her. Metz explains to Tom and Norm that Suba was killed by a lion. Tom pulls back the blanket covering Suba's body and notes the heart was cut out, something a lion would not do, only a human could be responsible. Tom, Norm and Gogi walk to the clearing in the jungle, the site of the prior night's ceremony. Tom searches for clues. He believes Suba was killed there last night. They find the carcass of the dead chicken. Using a stick to turn it over, they discover the bird's heart was also cut out. There is human blood on the altar. Norm and Gogi walk towards the jeep. They promise to return in three or four days. Tom hears someone approaching. He hides, with his gun drawn. Tonda appears in a very provocative leopard-print dress. Tonda explains she is unfamiliar with guns when reproached about wandering the jungle unarmed. Tom and Tonda talk. Tom admits to witnessing a ceremony the night before. Tonda lies and tells Tom she's never been in the spot before, but casually mentions she may have seen it in a dream.
Dr. Metz is researching something. Tonda brings in coffee. Tom enters the room and is invited to join the couple. Tom asks the doctor what is his specialty. Metz tells Tom it is psychology. Tom then asks about voodoo, volunteering he wrote a book about the subject in Haiti. Tonda leaves the room explaining she has a headache. Tom and the doctor continue their discussion about voodoo. Metz warns Tom not to get too curious about the matter.
Outside, Mara and the tribe grieve over Suba with a ceremony. Tom returns to his hut. Joe awakens, his chest badly scarred, and leaves his room. He seems to be in a trance. He walks right into the middle of the ceremony. He walks away and Mara follows him. Tonda returns from her walk and tells Tom she needs to talk to him. She admits she is afraid of her husband, the influence he has over her and the natives. Tom and Tonda embrace and kiss. Joe notices the encounter, pulls a knife and approaches the couple. Joe and Tom struggle and fight. Joe is finally knocked cold by one well delivered punch. Tom carries his friend into his hut. Joe comes to, but rambles incoherently in a foreign language. Tonda translates and tells Tom, "I kill white man."
Gogi and Norm are at the jeep. A minor repair is accomplished and they are on their way. Tom brings Joe a cup of coffee. Joe is still rambling. Tom confronts Dr. Metz in his office. He accuses Metz for Joe's behavior and pulls a gun on the doctor. He gives him thirty seconds to explain. Metz denies any knowledge, but Tom is unconvinced. The new houseboy, Kabar (Otis Greene) quietly enters the office and disarms Tom. Kabar escorts Tom outside. Tonda enters the room. Metz accuses his wife of infidelity. Mara comes to Tom's hut and comforts Joe. She is convinced Joe now houses the spirit of her late husband, Suba. Outside on the porch, Metz gives Tom back his gun and suggests they both go see Joe. Joe is gone. Metz tells Tom that he won't find his colleague and strongly advises he leave immediately. Metz reiterates, "I warned you, Maxwell. You remain here at your own peril."
Gogi and Norm arrive at the hut in the jeep. Tom tells Norm and Gogi that Joe is gone. They prepare to leave the next morning. Metz and his wife again argue over her attention towards Tom. She tries to reassure her husband. Metz informs Tonda that the strangers will be leaving in the morning. Tonda wanders over to the hut to talk to Tom. She tells Tom that her husband intends to kill her. Tom tells her he will take her with them when they leave. She is convinced Metz will try to stop her, so the only solution is murder. Tom flatly refuses to murder Dr. Metz. He slaps Tonda and tells her to stay away. He sends Tonda back to her husband. The next morning Tom and Norm dress and prepare to leave. They notice all the guns are missing. They rush to the jeep and find a spear in the gas can and the dead body of Gogi--a spear through his back. Tom and Norm go to the house to procure a few guns. They know Metz is with the natives and seeing no lights they assume the place is empty. They attempt to break into the gun case, but the noise arouses Tonda, who arms herself before she exits her bedroom. She confronts the burglars, but Tom charms her and gets her gun. Metz and Kabar arrive home. Metz unexpectedly gives Tom a rifle and ammunition. He asks Tom if he is taking his wife along. Tom tells Metz he is not in love with the doctor's wife. Metz informs Tom he wants to travel with the party and he does not intend to return to his wife or the village. In a fit of rage, Tonda stabs her husband. Tom and Norm take the injured man to his bed. Kabar volunteers he has gasoline for the jeep. Tom remains to talk to Tonda, while Kabar and Norm get the gasoline. Tom is horrified by the callous disregard Tonda shows for her husband. Tom informs Tonda she will be tried for murder if her husband dies, and reinforces his threat by claiming Kabar will be a witness. Norm and Kabar fuel the jeep, but Kabar falls ill. In the house Tonda is strangling a voodoo doll of the houseboy. Kabar dies in the jeep as lightning flashes and thunder claps. Tom is convinced Tonda was responsible and straps the body upright to the seat. He intends to fool Tonda into thinking Kabar is still alive. It works.
Tom goes back to the house. He stops Tonda from dispatching her husband with a pillow. Norm and the now deceased Kabar depart for the city to report the crime. Tonda is now worried she will be convicted and hang for the crime. She begs Tom for help. She formulates a new plan--another ceremony should do the trick. Joe wanders from his hut to Tonda. Mara tries to stop Joe, but Tonda takes him away. Tom, flanked by two spear carrying natives, encounters Joe and Tonda. They walk to the jungle clearing. Another ceremony is underway with Tonda dancing center stage. With dagger in hand, she walks to the altar. Mara watches hidden from sight. Tonda stabs a dead chicken. Joe approaches the altar and pulls the knife from the chicken. Tom's guards strip his shirt off and tie him to the altar. Joe stands over Tom, knife in hand. As he prepares to plunge the knife into his friend's chest, Mara appears and stabs Tonda in the chest. Tonda's scream distracts Joe and he snaps out of his trance. Joe cuts his friend free of the altar. Thunder and lightning scare off the natives and they scatter.
Sometime later Dr. Metz is on the porch recovering from his wound. Tom bids the doctor goodbye. We close with the three men driving away in the jeep. Mara and the natives gather to see them off.