Ness writes in a very engaging way, and he takes gender politics seriously. In the first book the protagonist, Todd, ran away from his community where all the women had been slaughtered. In this book the army of the all-male community conquer the capital city and set up prison camps for the remaining women. In response some of the women set up a guerilla force in the wilderness.
The book begins with Nietzche's famous quote about 'fighting monsters one becomes a monster', and this is the thread of the book. The men use torture, specifically waterboarding (the 'Ask') and the women blow up buildings (the 'Answer'). The women's terrorist campaign is seen as morally compromising, although it began as a response to gynocide. This parallelism is embodied in the young couple - Todd and an off-worlder, Viola - who are co-opted into the male army and the female resistance respectively. They must find a way to reconcile and forgive.
However this is not satisfactory to me. I don't think genocide and the resistance to it are morally parallel. For example the male army brand all women, like cattle (with metal tags brutally embedded in their flesh, but effectively branding). Todd does the branding. To my mind this is not forgiveable. There is no reconciliation back from that sort of thing.