Synopsis: "The Ninth Arch" contains the text and commentary on the "Book of the Spider," a 'received' text revealed to members of the Nu Isis Lodge of Grant's Typhonian O.T.O. The work completes Grant's trilogy of trilogies (The Magical Revival, Aleister Crowley and the Hidden God, and Cults of the Shadow) + (Nightside of Eden, Outside the Circles of Time, and Hecate's Fountain) + (Outer Gateways, Beyond the Mauve Zone, and Ninth Arch).