The Furies is the third book in the four-volume Holdfast Chronicles, a series of novels celebrated by feminists and science-fiction enthusiasts alike.
Alldera the Messenger was a slave to the Holdfast, where women are not women but fems, and all fems are the slaves of men. As Alldera the Runner, she escaped across the mountains to the grassy plains of the Riding Women (where men are unknown, except as a shadowy threat in the foothills).
Now, the Free Fems are coming back over the mountains to reclaim the Holdfast. And Alldera the Conqueror, leading this army, must faces new and frightful challenges on all sides. Eventually, Alldera discovers that—especially in war—friends can become enemies, and vice versa.