Falling to Ruin

From publisher blurb:

A few dozen stalwart souls stand at the edge of the ruin of Haggard Keep. Ahead lies the horde of the Fen Hag, their pennons and campfires and fell magics filling the entirety of the valley below. Behind are the refugees, the last people of the kingdom who are not already enslaved by the Hag, fleeing for their lives. All that stands between that army and the refugees is these sorry few. There's no one else left. It is a death sentence, of course. None of them are coming out of this alive. But they are the only chance that the refugees have. They need to give the refugees time. Time enough to escape. And they will buy that time with their very lives.