Late one night, a beautiful and well-dressed young woman, Grace, arrives in the mountainous old mining town of Dogville as a fugitive; following the sound of gunshots in the distance which have been heard by Tom, the self-appointed moral spokesman for the town. Persuaded by Tom, the town agree to hide Grace, and in return she freely helps the locals. However, when the Sheriff from a neighbouring town posts a Missing notice, advertising a reward for revealing her whereabouts, the townsfolk require a better deal from Grace, in return for their silence; and when the Sheriff returns some weeks later with a Wanted poster, even though the citizens know her to be innocent of the false charges against her, the town's sense of goodness takes a sinister turn and the price of Grace's freedom becomes a workload and treatment akin to that of a slave. But Grace has a deadly secret that the townsfolk will eventually encounter.

While in the hospital for a tomography of the brain of his autistic daughter Sarah, Ben becomes upset when there is a power failure. He decides to leave the hospital with Sarah, while the nurse Emily tries to convince him to leave Sarah for further treatment. They get the elevator with three other passengers, and suddenly the elevator stops; when the door opens, people has vanished from the hospital, the environment is creepy and they are chased by devilish monsters. They find that they are trapped in the hospital, and the creatures seem to be hunting Sarah.