Yin, a paradoxical, still, dark, chaotic, and unknowable principal. The oft forgotten counterpart to Yang, Yin is among the most mystical topics yet also the most difficult to describe. It has so many taboo, confusing, and paradoxical aspects. Yet, in its darkness lies the source of action, success, and meaning. Hidden in Yin life phases, experiences, and events is something secret and abundant. Through a Yin path, one can achieve huge outcomes by doing nothing. One can win by yielding and garner support by listening. One can manifest by waiting, impact through silence, and be strong through weakness. In other words, the Yin ways are the forgotten methods of moving receptively through life, begetting huge abundance with little effort. However, through thousands of years of Yang domination, only the Yang, active, and masculine methods of accomplishment have survived as the sole path to success. How can we tap into the mystical, powerful, and hidden strategies latent in a Yin way of doing and seeing things? The famous Taoist sage, Lao Tzu, advised to 'know the male but keep to the female.' His words indicated that if a sage could keep to the receptive and Yin path, then there is nothing he cannot do. Yin is the paradoxical headwaters of all manifestations, and by aligning ourselves with Yin methods we can, like ancient masters, siphon abundance from a Yin and Yang world. Yin Mysticism is an ontological treatise and hypothesis on the unknowable and dark half of all things: the wu-wei-like tactics for aligning with Yin.