Robert Caine, chief executive of Caine Enterprises, leads a group of political officials to a remote location, where his company intends to build a nuclear power plant. As Robert explains to the prime minister of a North African country how nuclear energy works, press photographer Sara Golan comments that a nuclear plant is as dangerous as a nuclear bomb. At the site, Robert and Sara visit a cave that has the name “Jesus” carved outside as Sara mentions a local prophet’s vision of a monster with “seven heads and ten horns, and on the ten horns, ten crowns,” that provokes the apocalypse. Sara takes a flash photograph of Robert as he stands by the cave wall. Later, in London, the North African prime minister attends a party at the home of Robert Caine and his wife, Eva, and son, Angel. Outside, an assassin lurks amongst the throng of anti-nuclear protesters while the prime minister expresses concern to Robert that his constituents are against the plant. There is an upcoming election and his political rival, Harbin, opposes the project. Moments later, Eva, a majority stakeholder in Caine Enterprises, shocks Robert by announcing that she intends to cancel the project, fearing a damaged reputation for the company. As they argue, the assassin attacks and fatally stabs Eva. After the funeral, Sara visits Robert and gives him a copy of the photograph she took in the cave. The flash picked up a carving on the wall, depicting a seven-headed beast. Sometime later, Robert visits the assassin in the mental institution, and the man proclaims Robert is the origin of evil. The next day, Robert and Angel fly to North Africa to meet Harbin, the new prime minister, to persuade him to allow the nuclear project to continue, despite safety concerns. When Harbin rejects their proposal, Robert and Angel return to the Caine Enterprises board of directors and instruct them to allay Harbin’s fears. Angel suggests they seek the backing of his former teacher, Professor Ernst Meyer, a Nobel Prize winning scientist. At Oxford University, Meyer runs his own tests on security systems. However, several weeks later, Angel, Robert and one of Meyer’s research colleagues, Professor Griffith, run different tests in a computer lab. When Angel feeds data into the computer, the system behaves erratically until it prints out a formula, “2√231,” but no one understands what it means. Later, on an airplane, priest Father Charrier tells Robert that the formula read backwards says “Jesus,” and that “Jesus,” written backwards, is a symbol of the Antichrist. Intrigued, Robert visits Charrier at his home and the priest shows Robert Biblical drawings regarding the apocalypse. Robert recognizes one of the images from the pictures in the cave. Robert returns to work to tell Angel and Griffith what he learned, but they laugh in his face. Robert leaves the office and finds Sara hiding in his car. She informs him of Harbin’s upcoming press conference, where he intends to condemn the nuclear plant project. When Robert seeks out Meyer for support, he learns the professor has recently disappeared. At the airport, Robert and Sara wait for Harbin’s arrival by helicopter, but as the prime minister disembarks, he accidentally walks into the propeller and is decapitated. Several days later, Robert returns to work and Angel informs him that Harbin’s temporary replacement approved their project. Robert later listens to a recorded message from Angel about the state of the nuclear plant while examining a model of the plant, and he remembers Sara’s description about the apocalyptic beast. On the tape, Angel describes the plant as having seven principal turbines, with ten commutators and ten automatic control systems. Robert realizes the nuclear plant is the seven-headed monster, then suddenly receives a call from the missing Professor Meyer, who warns Robert of the potential for catastrophic failure. However, Robert calls Meyer a religious fanatic and insists the nuclear plant is legitimate. Robert seeks solace from Sara, and they make love. Later, Robert has a nightmare filled with religious symbolism, predicting his “evil seed” will bring about the end of the world. The next day, Griffith worries about Robert’s health and performs a magnetic resonance imaging (MRI) scan. Angel explains it is protocol for everyone in the company. Robert tells them about his nightmare, and they worry about Robert’s mental stability. Griffith brings up the strange mathematical formula and thinks it might correspond to identification numbers in the company’s medical files. That evening, Angel meets Robert and Sara for dinner. Robert receives an urgent phone call from Griffith, who begins to tell him something about his nightmare before the phone cuts out. Back at the table, Sara announces she is pregnant. Meanwhile, at the computer lab, a falling piece of metal impales Griffith. Robert is disturbed by recent events and visits Charrier to discuss the situation. Charrier reports that the “second son” is the Antichrist who will “unleash the dragon.” He believes the dragon is the nuclear power plant and the second son is Sara’s unborn child. Later, Robert brings Sara to meet Charrier, but she runs in terror at the sight of the church. At home, Robert tells Sara she must have an abortion, but she refuses. Months later, Robert berates his board members for not being able to guarantee the nuclear plant’s safety measures, and he demands they start over. Robert later takes Sara to a gynecologist, but she becomes frightened, realizing she is being prepared for an abortion, and escapes. Months pass, and Robert has not seen or heard from Sara. Angel complains to his father that his constant testing is holding up the nuclear plant development and he is shocked to learn that Robert intends to shut down the project. At the computer lab, Robert looks over Griffith’s research notebooks, finds the formula and types it into the computer. A message from Griffith prints out, stating that the formula corresponds to Angel’s medical file; Angel’s MRI scan revealed that Angel is not human. Meanwhile, Angel returns to his apartment where he has been hiding pregnant Sara from his father. Elsewhere, Robert and Charrier discuss the revelation about Angel, and Robert explains that his son is the “second son,” as Angel’s umbilical cord strangled his twin brother at birth. Robert wants to confront Angel, but before leaving, he gives the priest a letter to take to the Geneva Conference that nullifies his contract to build the nuclear plant. He asks the priest to deliver the letter if something happens to him. Back at Caine Enterprises, Angel tells his father that he ousted him from the board by announcing that Robert had a nervous breakdown. Angel admits he intends to destroy the earth and kill Robert and Sara’s son. Robert chokes Angel, but security guards sedate him and send him to a mental institution. Meanwhile, Sara gives birth at a nearby hospital. Although Charrier catches Robert’s private plane to Geneva, the plane loses control and crashes, killing everyone inside. At the mental institution, Robert is restrained with a straight jacket and strapped to a gurney. However, the assassin finds Robert and unties him, then takes him to a room filled with other patients. Robert fends off an attack and escapes. At another hospital, Sara gazes at her son in the nursery ward. As one of the nurses prepares to feed the infants “vitamin drops,” Sara asks to take her son for a walk. In the hallway, Sara sees Robert stumbling toward her, begging to see their son. Sara shows Robert the baby as screams emanate from the nursery; the nurse accidentally poisoned the babies. Robert, Sara, and their baby escape. At Caine Enterprises, Angel takes over the board, claiming that Robert died in a tragic plane crash. Meanwhile, in North Africa, Robert and Sara care for their child. Robert cradles the baby as anti-nuclear protester chants echo in his mind.