Walter Sparrow is a family-man married with Agatha Sparrow, and works catching dogs in the Department of Animal Control and has a teenager son very close to his wife and him. On the day of his birthday, he is bitten by a dog and comes late to meet Agatha. While waiting for him, Agatha buys a detective book with a novel about the mystery around the number 23 in a bookstore as a gift to Walther. He becomes captivated with the story and obsessed with the number 23, finding many coincidences with his own life, and he decides to find the author, believing the story is about him. His further investigation discloses a mysterious situation that makes Walther paranoid.

Elisabeth Shue was originally cast in the female lead, but had to decline because she was pregnant.

Walter Sparrow:
She had a face that was meant to smile.

Factual errors: In the film, Walter Sparrow claims that the serial killer Ted Bundy died on January 23. Ted Bundy was actually executed on January 24, 1989. However, he was pronounced dead at 7:16 am (7+16=23).

Written by Billy Hayes (as Bill Hayes) and Jay Johnson (as Jay W. Johnson)
Performed by Dean Martin
Courtesy of Capitol Records
Under license from EMI Film & Television Music