This novel is about a dog named Enzo who can understand people but cannot speak. Through observing his master, a racecar driver named Denny Swift, Enzo gains tremendous insight into the human condition. He learns that in life, as in racing, it is not about going fast but using proper technique to navigate challenges. At the end of the book, Enzo recalls key events in Denny's life, including the loss of his wife and battle for custody of his daughter, before seemingly being reincarnated as a human as he had dreamed, preserving the Swift family.