The literature of the Great Perfection is divided into three sections or groups: The Mind Section, the Space Section, and the Upadesha Instruction Section. The Upadesha Instruction Section is represented by a famous set of Seventeen Tantras. The three Tantras translated in this volume are among these Seventeen Tantras. All of these Tantras, therefore, are filled with practical advice and pointing out instructions for the practice and realization of the Great Perfection. The Mirror of the Heart of the All Good One is a direct introduction into our own nature as the All Good One, a teaching on the practicalities of mandalas and of wisdom, and a description of the ways we can misunderstand what the Great Perfection means. The Arrangement of Precious Introductions contains actual instructions on many of the yogic practices associated with the Great Perfection. The Secret Kissing of the Sun and Moon is the source for the Song of the Vajra. Within the rubric of a teaching on the four kinds of bardos, it presents us with comprehensive descriptions of the practice of the Great Perfection as it applies to every aspect of our lives and deaths.