What the Peeper Saw is a British horror-thriller film from 1972 directed by James Kelley. The story revolves around a wealthy author and her 12-year-old stepson, Marcus, who live together in a grand mansion after the tragic death of the boy's mother in a bathtub accident.
As the story progresses, Marcus begins to demonstrate some odd behavior - a fascination with knives, a tendency to spy on people, and a cold demeanor. His stepmother, Elise, begins to grow increasingly suspicious of him and wonders if he is responsible for the death of his mother.
As the tension builds, Elise becomes more and more convinced that Marcus is a danger to her and anyone else who gets in his way. She seeks the help of a private investigator, who soon uncovers some shocking secrets about the boy's past.
The film features strong performances from its two leads - British actress Britt Ekland plays Elise, the troubled stepmother, while Mark Lester, a child actor known for his work in Oliver! and Melody, plays Marcus, the creepy and enigmatic young boy.
Overall, What the Peeper Saw is a well-crafted thriller that keeps viewers guessing until the very end. With its smart script, haunting score, and Hitchcockian tension, it remains a cult favorite among fans of the genre.