Know the time-shunned Leng by the ever-burning evil-fires and the foul screeching of the scaly Shantak birds which ride the upper air; by the howling of the Na-hag who brood in nighted caverns and haunt men's dreams with strange madness, and by the grey stone temple beneath the Night Gaunts lair, wherein is he who wears the yellow Mask and dwelleth all alone.