It's a story of survival, and sacrifice, as in the parts of ourselves we need to sacrifice to maintain our sense of self in the face of unimaginable hardship and privation. In this story, we meet two Jewish Poles and follow them through their very different wartime experiences. Many reviewers have disliked Rita, and while I understand why, I also understand why she was the way she was. Up until very recently, there was no realistic way for an intelligent self-aware woman to live life on her terms. After being her parents' daughter for 18 years, Rita grasped at straws to become her own woman by going to law school, but could not fool herself into believing she would be allowed to be independent. So she did what just about all women did - sacrificed her "self" and went from being someone's daughter to being someone's wife. By today's standards, I am somewhat of a shrinking violet, but even I cannot fathom the despair so many women must have felt at knowing they'll never be anything more than someone's wife and someone's mother.
Then comes war, and she must forsake all she thought she would ever have just to survive. No one goes through war unchanged, certainly not Rita. She finds herself in a situation that many might find easy to condemn, and I'm not entirely certain the lesbian relationship really added anything to the story, but again, you do what you need to to keep your sanity.
And this book managed to do something no book that I can recall reading recently has done: it got me thinking philosophically. This book discussed themes of not just right and wrong/good and evil, but why is something right or good, and why is something wrong or evil - just the sort of thing that creates immense discomfort in the small-minded who believe what they believe and never bother wondering why.