Tanith Lee

'Storytelling at its best and fantasy in its purest and strongest essence ... an artistic masterpiece' SF SiteHere is a world where demons and gods grant wonders and wreak havoc. The Upperearth, where the gods live; the Underearth, the realm of nightmarish demons; the Innerearth, the domain of the dead; and the Flat Earth itself, home of mortals. Supreme amongst all is the demon god Azhrarn, Night's Master, whose deadly whims could change the lives of those in the Flat Earth.
And Azhrarn is the keeper of a mystery which could alter the very existence of the Flat Earth for ever .