The Gnostic Mass is a hymn to the wedding of scientific truth and religious aspiration. It offers a truly modern spirituality. The celebrant is encouraged to leave superstition and dogma behind and join in an ecstatic tribute to the glorious nature of reality. Aleister Crowley wrote the Gnostic Mass in 1913. He described it as the central ritual--public and private--of Ordo Templi Orientis (O.T.O.). Today it is being performed on a regular basis throughout the world. The authors of this performance guide are both longtime O.T.O. members and consecrated bishops of the Ecclesia Gnostica Catholica (E.G.C.). They share between them over half a century of diligent practice and training with this rite. Their devotion has been rewarded with long-sought-after insights into its complex choreography. The detailed instructions presented here not only provide missing keys to the geometrical puzzle of the Mass, but offer a wider window into the workings of magical ritual. This book will thus be of value to spiritual aspirants, as well as to scholars and students of ancient myth, modern religious movements, and contemporary Gnosticism. The authors believe the Gnostic Mass to be a doorway into the highest realms of spiritual development and make a compelling case for that assertion. James Wasserman first performed the role of Priest in 1979. In 1992 he and Nancy Wasserman celebrated the most widely attended Mass in the history of the ritual, with a congregation of some 500 people. In 2009, they began to share their insights in book form. They released an improved second edition in 2010. This third and final elucidation solves certain remaining problems. James Wasserman is also the author of In the Center of the Fire: A Memoir of the Occult 1966-1989, a modern history of the O.T.O., and the editor of Aleister Crowley and the Practice of the Magical Diary. Nancy Wasserman is the author of The Weiser Concise Guide to Yoga for Magick.