Essence of Vajrayana is the first complete explanation in English of the Highest Yoga Tantra practice of Heruka body mandala. Buddha Heruka is a manifestation of all the Buddhas' enlightened compassion, and by relying upon him we can swiftly attain a pure selfless joy and bring true happiness to others. In Part One, Geshe Kelsang explains with great clarity and precision how we can practise the sublime meditations of Heruka body mandala, and thereby gradually transform our ordinary world and experiences into the transcendental reality of a Buddha. Then, in Part Two, he provides definitive instructions on the completion stage practices that lead to the supreme bliss of full enlightenment in this one lifetime. This is a treasury of practical instructions for those seriously interested in following the Tantric path.