While driving through a deserted stretch of land in the Southwest, Ben Holden, his little daughter K.T. and his girl friend Nicky spot a demolished car that has run off the road. Ben speeds to the nearest town, Hillsboro, to report the accident, but upon arriving, finds the townspeople barricaded in their houses, paralyzed by fear. Pete, the town sheriff, suddenly appears, and at gunpoint, throws Ben against his car and begins to interrogate him. After ascertaining that Ben has stopped in town to report an accident, Pete releases him, drawing the townspeople out of their houses. When one of them, Mike, runs at Ben with an axe, Ben jumps into his car and speeds off. Unknown to Ben, the town is on edge because twenty-six people have met grizzly deaths within the past seventy-two hours, and members of Mike's family have been among them. Pete, his deputy Tobey and Doc Duncan, who has recently retired to Hillsboro because of his heart condition, drive out to the wreckage and discover that the car's occupants have been crushed, with the exception of Timmy, the family's young son, who is now missing. Meanwhile, as Ben drives down the highway, he suddenly sees a young girl standing in the middle of the road, and while trying to avoid her, runs off the road, incapacitating his car. With no other choice, Ben, Nicky and K.T. turn around and walk back to town. Later, in Hillsboro, Ed Meadows returns to his house, and upon finding his son Stuart and daughter playing in the yard, hurries the children inside and chastises his wife Mildred for allowing the children outdoors. After Ed reveals to Mildred that he has learned her sister and her children have been in a deadly accident, the family, shaken, recites grace at the dinner table. That night, at the old, abandoned Barry house on the hill, several elderly people approach the door and are beckoned in by Doc, who in reality is the head of a coven of witches. The twelve elders who enter are also members of the coven, and later at the gathering, after pledging allegiance to Satan, marvel at a series of pedestals on which are standing the children destined to assume the witches' spirits. Later, as Ed is reading the bible to Mildred, their daughter's doll suddenly appears in the middle of the room, after which both adults die violent deaths. Stuart and his sister then join a group of children who are waiting for them outside and escort them to the old Barry place where they are welcomed by Doc. Soon after, Ben, K.T. and Nicky reach the Meadows house and find the dead bodies. The Meadows' bodies are taken to a meat locker where the rest of the town's dead have been deposited to be blessed by Jack, the town's priest. Ben and his family go to the sheriff's house to spend the night, and soon after, Doc comes to visit. When Pete ponders why Ben and his family have managed to enter Hillsboro while no one else has been able to enter or leave town, the priest suggests that malevolent forces are at work. Doc scoffs at Jack's theory and suggest that everyone get some sleep. Later, while pouring over books containing drawings of devil worship, Jack notices a preponderance of children's images. When Nicky wakes up screaming from a frightening nightmare, Ben announces that they are leaving. Although Pete doubts that Ben will actually be able to leave, he tosses him a set of car keys. On the drive out of town, one of the car's tire goes flat, and after stopping the car, Ben and Nicky turn around and realize that K.T. had slipped out of the backseat when they were not looking. K.T. joins the other children at the Barry house, where they play with party favors set out along a table, over which hangs murals of slain children and black-cloaked figures. When Ben and Nicky report K.T.'s disappearance, Jack announces that the witches took her. Producing a list of eleven missing children from the ages of six to nine, Jack explains that a coven of witches consists of thirteen people. He continues that the town was short of one female child, which is why K.T. was recruited, then warns that only four more boys of that age group remain, and that one of them will disappear next. Arming themselves with rifles, Tobey, Doc, Ben and Pete spread out to protect the houses of the four boys. At Mike's house, Mike sleeps as his little son Joey walks out of the house and into the woods in a trance-like state. Upon awakening, Mike notices that Joey is gone and follows him into the woods, where an armored horseman gallops by and beheads Mike. Jack follows Mike, and upon witnessing the beheading goes insane and wanders back to Ben and the others. After procuring one child for each witch, Doc approaches the altar to entreat Satan to connect a bridge between the dead and the living so that the elderly witches can cross over into the children's bodies. The witches then take their places beside the children standing on the pedestals. After finding Mike's headless body, Ben, Tobey and Pete, with Jack raving in the backseat of the car, drive up the road and notice the old Barry place on the hill. Upon searching the area, Pete finds a figure of a toy horseman, his lance covered with blood, and when Jack sees the figure, he screams in horror. Realizing that Jack was right, they break into the house, but are too late because the witches have all perished by blows meted out to them by a fiery sword, their spirits crossing over into the children. By the time Ben, Pete and Tobey break down the door to the room in which the ceremony was held, the witches and altar have disappeared and the room has reverted back into a dusty ruin. Around the cob-webbed covered party table stand the group of missing children.