Walter Sparrow (Jim Carrey) is just an ordinary dog catcher living an ordinary life when certain seemingly random events lead him to a book called The Number 23 by Topsy Krets. The fictional story interlaces a crime drama with a conspiratory look at the magical number 23. Walter is amused by the similarities between the main character named Fingerling, and himself. However, when the book continues to be eerily similar to his life, Walter becomes obsessed with finding out why. When Fingerling murders the leading lady in a fit of passion, Walter must figure out what is real...and what is fiction.