I have recently discovered that I have a thing for books about the multiverse. Something about the unknown, about the possibilities... that excites me. This book, this series, did exactly that. I loved the world that the author built and how she changed it between the various multiverses. I also loved the mechanism she used to tie the worlds together. By mechanism, I don't mean the actual Firebird, but how she makes those worlds accessible.
There is a lot of science involved in this series, but it is presented in such a way that it explains what it needs to without being anything like a lecture. It also is the perfect tool to create villains and heroes. The science behind travel between the multiverses is something that has lots of implications and applications, some with less positive ramifications.
This has been such a fantastic series, so beautiful. And I am so sad that the ride is over! This is a series I highly recommend for anyone who loves a thought-provoking, exciting read!