Who is Frater Achad and why should we study him? Besides Aleister Crowley, Frater Achad is the single most important Thelemite in our history. He discovered the secrets of which Crowley was oblivious and he proved that Crowley did not write The Book of the Law. His discoveries about the number 31 and how 31 (AL) x 3 gods = 93 is critical. He discovered the 93 Current. Crowley so loved his discovery that he changed the cover of 'Liber L vel Legis' to 'Liber AL vel Legis.'Achad also joined the A.'.A.'. in 1909, only a few years after Crowley established the Order. He, like Crowley, swore the Oath of the Abyss and became a Magister Templi. He was already in the A.'.A.'. when Crowley was approached by Reuss to join the OTO.Crowley's letters to Achad in these early years are the clearest description of how OTO sex magick works. Equally important are Crowley's views on women. Achad's breakup with Crowley is discussed in-depth, as is the debacle in Detroit, the Cefalu period and Achad's involvement in the Universal Brotherhood. We also address the question, "Who is Maat?"