Going in I thought this was a trilogy for some reason, so that may have affected my reading experience a bit. I thought I was getting answers and a conclusion, but instead it was another bridging volume.
What I enjoyed about this novel (seeing what was happening with Halli, seeing her motivations for things) was probably also what frustrated me the most about it. The way Halli was presented, especially when we see the life lessons her grandmother taught her, seemed very accurate. But that accuracy also meant that Halli was very selfish/self-serving. It was frustrating to see one character fighting so hard and being trapped in circumstances, while the other, even though she was trapped in her own way, used everything for her own advantage. Halli Markham's most important priority is always herself, so it was very upsetting to see her do whatever she wanted and not care about other people's feelings, most especially what Audie would have to deal with if she ever came back.
Interesting, Audie was the one I was frustrated with in the previous book, when she was caught up in Jake rather than a) being loyal to Daniel, and b) working on the switching bodies problem. I really liked how Audie recommitted herself to the issues in this book, even though she's very quickly waylaid by her health and her (Halli's) parents' influence over her.
As I said, I was expecting conclusions, so I was a bit frustrated when there was a lot of thought process going on here, but not a lot of action. However, the next novel will be the final volume, and I'm still very much looking forward to seeing how Robin Brande will bring everything together. I really love how she's brought real science (or at least the love of science and scientific theory) into science fiction.