The neighborhood community group for Maple St. is meeting at Tyrone's home. Some of the parents are absent to attend their childrens' soccer game. The group is just wrapping up their meetings when Phyllis, whose husband is in the Army, notes that the new family that just moved in has put up an unsightly chain fence. Dylan, a jock-type parent, thinks the family is weird because they didn't put up an American flag on Veterans Day. The intellectual Will Marshall seems amused by the pettiness of the whole thing. They're interrupted when all their cell phones go off simultaneously. The Game Boy belonging to Dylan's son Jason goes dead. A few seconds later there's a piercing noise, the ground shakes, and every window in the house shatters.
The community meets on the streets to try and figure out what is going on. Phyllis mentions that her husband said there was increased terrorist activity overseas, and Dylan thinks they're under attack. Tyrone and another neighbor, Simon, try to go to the soccer field to find the other parents. However, their car doesn't start. People wonder if the community was hit with an electromagnetic pulse.
Dylan decides to go confront the new family and Will insists on going with him. The family doesn't answer the door and everyone goes home. Will is still smug about the whole thing and his wife Holly gives him a hard time, accusing him of being a snob. He admits that he didn't want to move here, and doesn't think much of any of their neighbors.
Night falls and Dylan starts riling up the neighbors against the new family, insisting they're terrorists. Will tries to calm everyone down but Dylan is sick of his condescending attitude and comes at him with a broken bottle. Will manages to fend him off but they're interrupted when someone drives a SUV past the group and to the new family's house. The lights in the house come on as the SUV pulls into the garage. Dylan thinks that proves they're terrorists but Will notes that there's no reason they'd draw attention to themselves by having electricity. Dylan pulls out his gun but Will convinces him to stay there while he talks to the new family. After a few minutes, he emerges and tells everyone that the father works the night shift at an electrical firm and has told his family not to open the to anyone when he's not there. When Will informs his neighbors he told the family to stay inside because of the hostile atmosphere, Dylan accuses him of being a terrorist and prepares to shoot him. Will points out they all have something that makes them look guilty, and challenges Dylan to shoot him. Dylan gets hold of himself… but then his son notices a spy camera on their house. The neighbors search their houses and find other cameras. Connecting the new father's job at an electrical firm with the cameras, the mob attacks the house. Dylan and Jason throw torches through the window and shove Will to the ground when he tries to stop them. The entire neighborhood bursts into the house as the new family cowers in fear.
In a nearby van, two soldiers are watching the situation on a hidden camera. They note how long it took for the neighborhood to descend into chaos and worry about the civilians panicking so easily.