Book excerpt: A spiritual classic along the lines of The Tibetan Book of the Dead, this text is a clear and accessible guide to the essence of Dzogchen and the attainment of Buddhahood. A text belonging to the same cycle as The Tibetan Book of the Dead, this instruction on the method of self-liberation presents the essence of Dzogchen, The Great Perfection, regarded in Tibet as the highest and most esoteric teaching of the Buddha. Teaching the attainment of Buddhahood in a single lifetime, this text was written and concealed by Guru Padmasambhava in the eighth century and rediscovered six centuries later by Karma Lingpa. The commentary by the translator is based on the oral teachings of Namkhai Norbu Rinpoche and Lama Tharchin Rinpoche.