Horror House

A group of twenty-something friends in Swinging London decide to spend the night in an old, supposedly haunted mansion where one of their number used to play as a child. Among the group is American ringleader Chris, his bored girlfriend Sheila, promiscuous Sylvia, and his "good girl" date, Dorothy. They have fun exploring the mansion, even holding a séance before separating one by one by candlelight on the moonlit night. As they are shaken by one brutal murder after another, they become convinced that one of them must be the killer - but can they uncover the truth behind the haunted house and the sinister forces at play?