The story is about five-year-old Ruthie. Ruthie doesn't have a brother, a sister, a cat, or a dog but she has an imaginary friend, Jessica, "who is even better." Although Ruthie's parents tell her that "There is no Jessica," Ruthie knows that there is. The book describes all of the activities that Ruthie and Jessica do together and concludes with Ruthie's discovery of a "real" Jessica when Ruthie begins kindergarten.
