From the back of the book:
"'At a crossroads of the lower planes, past the ancient portal called the Threshold and its twin stone guardians, lies the Midnight Realm. It is a grim and foreboding place of otherworldly aspect, where rivers of molten iron flow across a desolate landscape of smoldering plains, virulent swamps, and forests of pale deadwood trees. By day, a black sun casts dark shadows over the Realm. By night, the sun sets, and the land is lit by the wan light of distant stars, moons, and suns.'
Welcome to the dark side of the Talislanta milieu: An eerie twilight world inhabited by Tarteran demon hunters, Ebonite soul traders, merciless Brood reapers, and many other terrifying and mysterious denizens of the lower planes.
Midnight Realm is a dark fantasy setting that provides players and Game Masters with an exciting new world to explore. Designed for use with the Talislanta Role Playing Game, Midnight Realm can also be adapted for use with other RPGs, or simply used as a source of new ideas to add to your own world."