A real estate mogul, Scott Crane, is watching a newscast about a family that was killed in a blaze, including their two children. He gets a call from Rick, the arsonist that he hired. Rick demands extra money since Scott didn't tell him there was a family in the house. Scott stands to make a bundle from the land the house was on and refuses to pay. Rick says he knows where he can find Scott, because he knows he's agoraphobic and never leaves his house. Scott insists he can leave his house any time that he wants, but Rick is unimpressed.
That night, Rick goes to bed but hears a noise outside. He puts a gun underneath his pillow and turns off the lights. The temperature starts to go up and Scott finally notices but is unable to get the thermostat to work. He hears noises downstairs and takes his gun to investigate. The TV is on but no one is there. Scott turns the TV off but it switches back on to a broadcast about the two dead children. Scott calls out for Rick but there's no response. He hears a whistling noise and goes out to the kitchen where someone has put a teakettle on the stove. He turns off the stove and burns his hand on the teakettle. When he turns on the water at the faucet, it's boiling hot. The police call and the investigating officer Kate Graham informs Scott that they've determined a faulty boiler caused the fire.
Scott goes to make a call but discovers the phone line has been cut. He braces himself to go out, calling out to Rick that he's going to bring the cops back. However, Scott's unable to step outside. He hears footsteps above and runs upstairs, but doesn't find anyone. The lights flicker and Scott goes to the garage to check the fuse box. He finds Rick, electrocuted, standing at the fuse box.
Scott sits down and has a drink, and sees a reflection of the two dead children in the windshield of his car. Scott heads for the door and tries to explain that it was just business for him and he can try and help them. The doors start to open and shut on their own. Scott retreats to the kitchen and notices that the gas knobs are turning on by themselves. The fireplace starts up and Scott tries to turn the gas off. The knobs keep turning and Scott manages to go outside and inch his way around the house to the gas meter. He shuts it off then runs inside.
Someone knocks on the door: Kate Graham, who says that she set up the fire to look like a boiler. She's there to get her money from Scott, and he tells her about the ghost children and the dead Rick. He wants her to help him negotiate but Kate figures he's nuts and just wants her money so she can get out. When he refuses to pay her, she leaves and Scott tries to apologize to the ghosts. The two children appear and Scott offers them his house. When they don't respond, he tries to get out but the door knob turns red hot and then the door bursts into flames. Fires spread throughout the house and Scott runs upstairs only to find all the doors are locked. He finally gets into the bedroom only to find the two children waiting for him. He locks himself in the closet as smoke and flames fill the house and the children just smile.
The next day, Kate comes to the house and finds the strongbox where Scott kept his money. She takes it back to her apartment and opens it, then lights a cigarette. She dozes off with the money… as her cigarette falls on the money. The fire starts to spread as the children watch and the apartment starts to burn.