The Haunted House of Horror, also titled Horror House and The Dark, was an early type of teen "slasher film" set in late '60s England. It starred Frankie Avalon and Jill Haworth as young adults looking for a thrill by spending the night in an old mansion in the English countryside. Although portraying a teenager, Avalon was nearly 30 years old at the time of filming. It was directed by Michael Armstrong who would go on to direct Mark of the Devil.