Night's Master
World Fantasy Award finalist and the founding volume of the Flat Earth cycle — a key text of mythic, eroticised fantasy whose influence runs through Gaiman's Sandman (acknowledged) and modern dark fantasy generally.
Series Guide
Tales from the Flat Earth
by Tanith Lee
Lee's cycle of demon lords and mortal playthings beneath an antique flat world — Night's Master, Death's Master and their successors, told in prose like dark silk.