In suburban Chicago, Sarah Clarke suffers a car accident during the third trimester of her pregnancy, which leaves her husband dead, and her partially deaf.

On Christmas Eve, she prepares for her child's birth which is due Christmas Day. That morning, her neighbor and friend, Isaac, visits, and the two exchange gifts. Sarah phones her mother, who is traveling to stay with Sarah that night. After falling asleep that evening, Sarah awakens to a knock at the door from a woman claiming her car has broken down.

Sarah goes back to sleep, but the woman infiltrates the house and drugs her with chloroform before injecting her with oxytocin. Sarah awakens as the woman prepares to abduct her unborn child. The two fight, and Sarah flees down the hall, locking herself in the bathroom.