Blood in the Valley - Heroes of the Valley, #2

They thought they'd won. They thought it was over. The Defenders of the Remordan Valley have smashed the barbarian horde that spilled out of the frozen wastes to plunder their cities and farmlands. They've blasted the wizard that incited their rampage from existence. They've slain the elven traitor that led them. But it was all a ruse. It was all a distraction. While the defenders were facing a human threat in the north, a thoroughly inhuman one has risen in the south.
Slavering goblinoid legions now roll up out of the wilderness, across a frontier stripped of its guardians, led by a re-awakened demoness freed of the bonds of hell and bent on domination. And the traitor has somehow returned at her side - not just for vengeance, but to prove to the woman he still loves that he was right. There will be Blood in the Valley.