Walter Sparrow is an animal control officer married to Agatha; they have a son, Robin. At a bookstore, Agatha begins looking at a book titled ''The Number 23'' written by Topsy Kretts. She later gives Walter the book as a birthday present. Walter starts reading the book, noticing odd similarities between himself and the main character, a detective who refers to himself as "Fingerling (character)." Mirroring the detective, Walter becomes obsessed with the 23 enigma, the idea that all incidents and events are directly connected to the number 23, or to some number connected to 23. When he tries to warn Agatha about the number, she tells him he is crazy.