A riveting novel about a female anthropologist. The narrative jumps between the story of her marriage in England, and the story of her time observing chimpanzees in Africa. It's not a thriller but it builds to an almost unpleasant level of suspense. There are some brutal bits of animal violence which I found very hard to read -- why is it so much harder to read about cruelty to animals for me than it is to read about cruelty to humans? Is it because I know humans better than I know animals?