Don't Open the Patio  (1980)

Also Known As: Don't Forget to Lock Your Windows, Helen Hides in the House, Knock Knock

Genre: Horror

Starring: Sandy Fandango

Plot:
A teenage girl, home alone at night, spends an hour and 26 minutes running around her parents' house with the lights off, calling out, "Hello?"

Suspense builds to a climax when a shadowy figure appears at the window.

Quotes:
Helen: "Hello?"
Helen: "Is there anyone there?"
Helen: "Hello?"

Most Helpful User Review:
I first saw this film when I was 10 years old; it scared me so much that I dived behind the sofa, farted really loudly, and my whole family took the piss for weeks. Traumatised for life.

BIFTA Nomination: Best Lighting and Shadows (1981)

Directed by: Red Lester. US. Colour.