Adventure novelist Tom Harris [William Joyce] leaves the bright Miami Beach for the remote Voodoo Island in the Caribbean to do research for his next book, traveling with his publisher Duncan Fairchild [Dan Stapleton] and Fairchild's wife Coral [Betty Hyatt Linton]. The trio, eager for material and inspiration, heads into uncharted territory, hoping to uncover eerie legends and deliver a compelling adventure to their readers. As they press inland, a sudden crisis strikes—their plane runs out of fuel and Tom must take the controls from the pilot Enrico to make a rough landing on a welcoming, sunlit beach that soon reveals a far more dangerous atmosphere.
Tom moves toward a house he spots in the distance, but a stark distraction stops him: a young woman is swimming naked in a pond nearby. A zombie materializes from the shadows, yet vanishes as Tom dives into the water in a tense bid to reach it. After a worried fisherman seeks help, the zombie reappears with menace, decapitating the fisherman with a machete. Tom fires his weapon in a fruitless attempt to stop the undead, and the zombie bolts when armed men arrive in a Jeep. The leader, Charles Bentley [Walter Coy], flatly denies the existence of zombies, insisting that the island’s simple people cannot grasp the notion that a man could be deranged or homicidal in mind. The tension between belief and fear sets the tone for what follows, a struggle between superstition and science that permeates every corner of the island.
Back at the plane, Duncan [Dan Stapleton], Coral [Betty Hyatt Linton], and Enrico are frightened by the locals’ hostility, but Charles orders them to secure the plane and introduces himself as the overseer of Voodoo Island. At Charles’ home, Tom presses about voodoo drums and human sacrifice, only to learn the housekeeper—who is secretly part of the voodoo cult—feigns ignorance about such rites. The atmosphere grows increasingly ominous as night falls, and the promise of danger becomes a chilling reality.
Before dinner that night, Tom meets the woman he spotted earlier: Janine Biladeau [Heather Hewitt], the daughter of scientist Dr. Augustus Biladeau [Robert Stanton]. Tom insists on sharing the zombies’ strange behavior with the group, and Augustus, a pragmatic mind, dismisses the idea, suggesting that the islanders rely on a plant-based narcotic that can induce strange physical and mental effects. Yet the conversation only deepens the mystery, hinting that something far more sinister lurks beneath the island’s tranquil veneer.
Tom and Janine take a walk together and are suddenly attacked by zombies that attempt to abduct her. Charles warns that Janine faces possible sacrifice if she remains on the island, because she is a blonde virgin. Tom pleads with Janine to flee with him and the others the next day, but she refuses to abandon her father to whatever fate the island holds. Meanwhile, the voodoo cult conducts a ceremony led by a masked figure, Papa Neybo, adding a ceremonial gravity to the escalating crisis.
The following morning, Tom urges Duncan to assemble everyone at the plane for a planned escape. Janine has decided to go with them and to urge her father to leave as well. She accompanies Tom to Augustus’ laboratory, but her friend Fernando warns that kidnappers may soon seize them. Augustus—driven by a mission to cure cancer—works with irradiated snake venom, and when he injects a man with it, the patient instantly transforms into a zombie. Augustus begs Tom to take Janine away, admitting that it may already be too late for him to leave as the island descends further into chaos with continual zombie attacks.
As chaos erupts, Tom, Duncan, and Enrico scramble to prepare for take-off while zombies grab Janine and Coral. Enrico starts the plane, but a zombie infiltrates the propeller’s path, carrying a box of explosives that detonates, killing Enrico and destroying the aircraft. Tom and Duncan dive into the sea and later encounter a motorboat, slipping away from the disaster. They then disguise themselves as voodoo cultists to infiltrate the ceremony in a bid to rescue Janine, unaware that Augustus is watching the ritual unfold with interest. Just as Neybo is about to behead Janine, Augustus throws a knife, killing Neybo and revealing him to be Charles.
Tom, Janine, Coral, Duncan, and Augustus race back to the lab, pursued by cultists and the undead. Augustus rigs his equipment so that it will explode and destroy Voodoo Island, thwarting Charles’ plan to seize the world with a zombie army. As they escape by boat, two cultists board and fatally stab Augustus. In his dying moment, he explains that the zombies were an accidental byproduct of his experiments, and that Charles had exploited that knowledge to pursue conquest. The island erupts in a cataclysmic explosion, and the remaining survivors sail back to the safety of Miami Beach, leaving behind a legend that the island’s dark science and dark magic have finally been beaten—for now.
