Explore the second part of "The Joy of Axion Theory" lecture delivered by Anson Hook from the University of Maryland as part of the KITP Program "What is Particle Theory?" (#particles25). This 90-minute lecture continues the exploration of axion theory within particle physics, combining formal, computational, and phenomenological approaches to address central questions in the field. The lecture is designed to bring together diverse perspectives and methodologies to accelerate progress toward long-standing goals while potentially generating entirely new questions in particle theory. Part of the weekly "The Joy of..." series, this presentation offers valuable insights for researchers and students interested in theoretical particle physics and its ongoing developments.