"Conan's scalp prickled. In Stygia, that ancient and evil kingdom that lay far to the south, he had seen such black dust before. It was the pollen of the black lotus, which creates death-like sleep and monstrous dreams; and he knew that only the grisly wizards of the Black Ring, which is the nadir of evil, voluntarily seek the scarlet nightmares of the black lotus, to revive their necromantic powers.
The Black Ring was a fable and a lie to most folk of the western world, but Conan knew of its ghastly reality, and its grim votaries who practice their abominable sorceries amid the black vaults of Stygia and the nighted domes of accursed Sabatea."
Chapter 4: 'From What Hell Have You Crawled?', The Hour of the Dragon, Robert E. Howard