The girl Maryann has just moved to the house of her Grandfather and Grandmother in the countryside after losing her parents. She is lonely and misses her former friends and decides to wander around the area. She finds the secluded boy Andy, who lives alone with his mother, the surgeon Dr. Katherine Young, and his father, the nurse Richard Young, in an isolated house. They immediately befriend each other and she enters in his room through the window to play video-game with him since Andy depends on a wheelchair to locomote. On the next day, Maryann visits her new friend again and Richard let her in to play with Andy. On the next day, Katherine does not allow Maryann to visit her son and she goes to the house of her grandparents to forbid Maryann to visit her son.
However Maryann insists on visiting Andy when his parents are absent; out of the blue, they return and Maryann is trapped inside the house. She goes to the basement expecting to find a way out and stumbles with a dark secret. What has Maryann discovered about Andy's parents?.