The tranquil coastal town of Midwich, located in Marin County, California, experiences a strange phenomenon when its residents mysteriously fall asleep at 10 AM for a prolonged period, only to awaken at 4 PM. Following this peculiar event, a shocking twist unfolds as ten women of child-bearing age unexpectedly become pregnant, including a virgin girl and a married woman, Jill McGowan, whose husband has been away working in Tokyo for a year.
The women, despite having vivid dreams, choose not to seek abortions, and all the babies are delivered in a barn on the same night. While five boys and five girls enter the world, one child, the virgin's daughter, tragically succumbs to stillbirth due to umbilical cord asphyxia. The surviving children are strikingly distinct, boasting exceptionally pale skin, white-blonde hair, and cobalt eyes, coupled with remarkable intellects.
However, they lack conscience and individual personalities, demonstrating unsettling psychic abilities that can lead to violent outcomes if they are in pain or provoked. The children form pairs akin to mating, yet David, the would-be mate of the stillborn girl, finds himself on the outside looking in. Though David retains some psychic powers, he stands out for his ability to express genuine human compassion. He reaches out to his mother, Jill McGowan, and begins to grasp the complexities of his existence.
Among the children, Mara, the daughter of the town's physician, Dr. Alan, and his wife, Barbara, emerges as a powerful leader. Mara has a sinister past; as an infant, she used her powers to manipulate her mother into taking her own life by jumping off a cliff. As the children begin to gain notoriety for causing accidental injuries and fatalities among the townspeople, they relocate to a barn for safety.
The situation escalates when local priest Father George tries to confront them, but Mara uses her powers to compel him to turn the gun on himself. It's discovered that similar "blackout" children exist in other countries, where they were often exterminated for their inhumane characteristics, sometimes resulting in the destruction of entire towns. In a dark turn, one of the researchers, Dr. Susan Verner, reveals a well-preserved alien corpse of David's intended mate, only to be forced into a tragic end by the children she studied.
The mounting tension culminates when an angry mob attempts to drive the children away, but their efforts culminate in chaos. As the scientific team scrambles to escape, Dr. Alan formulates a desperate plan to detonate a bomb hidden in a briefcase within the children's classroom. Using his abilities, he creates a mental barrier to keep the bomb's presence hidden from the children. However, when Jill McGowan pleads for Alan to spare David, complications arise as Mara senses the hidden danger and exposes the truth.
The situation spirals out of control when the clock strikes, triggering the bomb’s explosion and claiming the lives of all within, including Dr. Alan. Outside, as devastation envelops the classroom, Jill clings to David and assures him, > "We'll go someplace where nobody knows who we are."
