Philip is in despair at the thought of having to stay with 'stuck up old aunt Jane' in her vast gloomy mansion. Worse still, his awful cousin Susan is living there too. At first Susan and Phillip dislike each other intensely, but form an uneasy alliance when they discover the secret room upstairs. If it has been empty for several years, why is there a light on there every night? Intrigued, the two cousins start to investigate. As they dig deeper and deeper into the past the terrible secrets of the house on the hill start to unfold...