Helen and Martine run unusual establishments: "sex shops," one in Los Angeles and one in New York, that never ask payment for their wares. They aren't in business to sell "novelties." They aren't there to make a profit. Their enterprise is more serious than that: an effort to buttress the erotic spars that hold Mankind above the level of the beasts. "Priestesses" chronicles the adventures of two priestesses of erotic desire, commissioned from On High to spread erotic knowledge among those who need it. They labor in the shadows to avert both the chaos of untempered lust and the despair of desire too tightly shackled. Either could plunge human civilization into eternal darkness.