The Vengeance of Gwa

King Bwene of the Baradi faces a stark dilemma. A plague is devastating his people, and the only possibility of salvation is relocating his kingdom from the lowlands to a place where the disease doesn't flourish. But when he attacks the ape-men of the plateau, suddenly the hordes of semi-humans come boiling down from the heights, overrunning his land with their superior strength and numbers.

He sends emissaries to the Ho-Tus, another race of humans on the other side of the plateau, to seek their help, but they kill anyone unrelated to them. As the days grow ever darker and the prospects of his people's survival diminish, Bwene must deal with a murderous Queen, treachery within his own ranks -- and a beautiful refugee from the Ho-Tus!

Another classic fantasy by a master of the genre.