Explaining the process and energetics of Daoist internal alchemy, the author describes in detail the practice of Nei Dan, the alchemical firing practice of Daoism that has until very recently been a closely guarded secret. Drawing together a huge amount of esoteric material on the hidden aspects of Daoist practice, he presents theory and practice coherently for western practitioners. He offers his own experiences of each stage of attainment, describing the tangible results that should appear, and provides guidance on the practicalities and potential pitfalls of alchemical training.