In this article, the authors explain how nonfiction literature can demonstrate the nature of problem solving within disciplines such as math, science, and social studies. This literature illustrates what it means to puzzle over problems, to apply disciplinary thinking, and to develop creative solutions. The authors look closely at three examples of what they refer to as "the literature of inquiry." Using the concept of the dance of agency--real people actively using knowledge and disciplinary ways of thinking to get things done--they consider these questions as they discuss each book: (1) Who is doing the investigating?; (2) What is the problem?; (3) What is the process of investigation?; (4) What are the results?; and (5) Are they convincing? When discussing selected books, the authors first provide a brief summary of the inquiry being discussed, and then focus on how one of the selected features of inquiry propels the process forward. These features--which in reality operate together--include: (1) personal identity, or seeing oneself as a person who is open to new ideas; (2) agency, or making an impact; and (3) knowledge, both content and procedural. (Contains 1 table.)