In the small English village of Midwich, physicist Gordon Zellaby is speaking on the phone with his brother-in-law Alan Bernard, a military officer at the London War Office, when Gordon and all the townspeople and animals suddenly fall unconscious. Concerned when he cannot reach anyone in Midwich, Alan drives towards the town and watches as a constable just ahead suddenly slumps to the ground near a bus, which has stopped in the road because its driver and passengers are under the same spell. Wary bout proceeding, Alan asks his commanding officer to send the southeastern command to investigate. Within hours, the military has set up a perimeter around the town and tests the area by sending in a soldier with a gas mask as a plane monitors from above. The soldier quickly drops to the ground unconscious, while the pilot also passes out, crashing his plane. Several minutes later, however, the bus passengers, constable and nearby cattle all awaken from their spell. In the Zellaby home, Gordon and his wife Anthea realize that they both have been unconscious for hours and are shocked when Alan informs them that the entire village passed out. Military troops move into Midwich and search the ground with detectors, but are unable to determine the cause of the “time out.” While Doctor Willers notes that no one was seriously hurt, the townspeople are deeply disturbed by the incident. In the interest of national security, the military orders that the incident be kept top secret and begins surveillance of the Midwich citizenry. Weeks later, Anthea discovers she is pregnant, while spinster operator Miss Ogle and a virgin teenager are also pregnant but cannot explain why. It is soon discovered that every woman capable of giving birth became pregnant the day of the mysterious spell cast on Midwich. When a nursing station is set up for the women, Willers tells Gordon that x-rays reveal the fetuses are in a very advanced stage of development. Despite Gordon’s attempts to reassure Anthea that she will have a normal baby, she and all the villagers fear the upcoming births. All twelve babies are born within hours of each other and are similar in their features, including blonde hair and strange, arresting eyes. At four months old, Willers notes that all of the babies have the physical development of eighteen-month-old children. One day, while Anthea is feeding her infant David, the child's stare sends his mother into hysterics. Months later, Gordon shows Alan how David easily solves a puzzle box that even Alan has a hard time resolving. Gordon then takes Alan to meet two of the other children who also easily open the trick box. Gordon, who has been monitoring each child's growth and behavior, explains that if you demonstrate something to one child, that all the children know the solution. Gordon thus concludes they share a common consciousness. Although still the age of toddlers, the children appear to be school age and scare the villagers with their glaring eyes. They demonstrate telepathic abilities, prefer one another’s company and politely refuse their parents' attention and love. When Alan suggests the children are evil, Gordon assures him that they are exceptionally bright, but must be taught to understand human interaction. Soon after, Gordon and Alan meet with a committee of government and military personnel and discover that there were many “time outs” simultaneous to Midwich and consequently other colonies of such children exist, including one in northern Australia, where a similar brood of children died within ten hours of birth, and another in the artic, where a group of babies was killed because of suspicions about their blonde hair and fair complexions among the dark-skinned Eskimos. While one doctor believes that a "jump" in human development has taken place, another doctor hypothesizes that the earth received impulses of energy from beings in outer space. Assuming that a series of accidents in Midwich are attributable to the mysterious children, the committee decides to imprison them, but Gordon asks for one year to teach them as a group and monitor their behavior. Over the next few months, Gordon learns that the children, who are under his instruction in a house on the outskirts of town, have limits to their mind reading capabilities. When he asks them if they know of life on another planet and what they plan to do with their telepathic powers, the children refuse to answer, leading Gordon to assume they have plans to control the earth. One day, a man accidentally hits one of the children with his car. Although the child is unharmed, the group uses their telepathic gaze to cause the man to drive into a brick wall, killing him. The brother of the deceased believes that the children caused the death and plans to kill them, but the children, sensing his hatred, use their powers to make him shoot himself in the head. Although Gordon, Alan and Anthea witnessed the event, they were caught in a trance created by the youngsters and were powerless to stop it. Later that night while Gordon, Alan and Willers discuss their options, General Leighton calls to tell them that the Russian army has annihilated the village of Raminsk where another group of “time out” children began wreaking havoc. Meanwhile an angry mob of villagers take torches to the children’s house, but the children put them in a trance and cause the leader of the group to set himself on fire. Soon after, when Alan demands to know why David killed the man, the boy informs him that the children know about Raminsk and have decided to survive no matter what the cost. Later that evening, David goes to the Zellaby home to tell Gordon that human emotions hinder their capacity for power and to ask him to make arrangements by Friday to help the children disperse throughout the country covertly. When Friday arrives, Gordon asks his wife to drive Alan back to London while he attends to the children. Now alone, Gordon arms himself with dynamite in his briefcase and imagines a brick wall to protect his thoughts from the children’s mind reading skills. Meanwhile, on the road, Anthea suddenly realizes that there was something strange in her husband’s request and turns the car around. At the house, the children sense Gordon is nervous during his lesson but are unable to see through his “brick wall.” Using their powers, they shake Gordon’s concentration by causing the wall to crumble, but Gordon succeeds in holding off the telepathy long enough to detonate the bomb. As Anthea looks on, the explosion kills the children and Gordon, who has saved the world from the control of the aberrant children.