Not my favorite of Butler's work but a good quick read. I thought the mechanic of the parasite was inventive. It was an idea that stuck with me for a while. Also the questions the novel raises of free will and humanity gave me food for thought. A lot of Butler's work deals with how communities are built and new futures for humanity that may not be human, and that shows up here as well. I think Keira and Rane were my favorite characters, but they were all interesting.