This is the sixth in the series of nine volumes that constitute Grant's Typhonian Trilogies. Hecate's Fountain is a highly original approach to contemporary Hermetic thought and experimental occultism. During the rituals of New Isis Lodge (1955-1962) it was noted that not all of them achieved the object for which they were performed. The exceptions had curious and often alarming side-effects which the author calls 'tangential tantra'. It was discovered that these anomalies effected a rapproachment with highly-charged dimensions existing between the realms of dreaming and dreamless sleep. This catalytic interface Grant calls the Mauve Zone. The weird nature of these phenomena suggested parallels with H.P. Lovecraft's Cycle of Myths extrapolated in the fabulous Necronomicon, and its affinity with Mauve Zone magick is here meticulously explored. The Magical Workings of New Isis Lodge have opened the gates to an influx of influences from Outside that will radically alter the direction of experimental occultism.