“Tantra,” “Tantra-Yoga,” and “Tantrism” are all terms that refer to one of the most sophisticated and fascinating spiritual approaches in the world. It also has been the single most influential approach on the Indian subcontinent, and many of its concepts and practices have found their way into mainstream Indian culture and philosophy. Tantra, moreover, has given the world many great masters (known as siddhas and mahâ-siddhas), who have left precious teachings behind. These teachings are still largely a sealed book, and in order to comprehend— never mind realize—them, we must be willing to actually tread the Tantric path under the guidance of a qualified adept.