During the five years while Livy is absent, Bob reads the dictionary in the closet. Initially, this is a way for him to pass the time and to stave off potential boredom. But Bob relishes the knowledge that the dictionary brings, retaining the new words and definitions he learns and frequently recalling them. That he laments being unable to read when it becomes too dark demonstrates this love of knowledge. Likewise, he turns to the dictionary to teach him how to comprehend and navigate the human world, indicating his intelligence and resourcefulness.

Bob and Livy both recognize that books such as a dictionary are tools for discovering how the world works and for uncovering the unknown. They initially use the dictionary in hopes of discerning what Bob is, quickly ruling out Livy’s initial assessment that Bob is a green creature. Defining what Bob is, they agree, could be key to determining how to return Bob to his home.

In this way, Livy and Bob’s hypothesis is correct, as the answers to their questions lie not in the traditional dictionary but in another kind of resource book: A to Z. Once they have remembered this book’s existence via the help of Livy’s time capsule, Bob and Livy learn that Bob is a well dweller.