A sweeping conclusion to the trilogy, with a (mostly) satisfying ending... In this book, Christine and Face-Off manage to extract themselves from trouble, get some training, and then deal with the Very Big Trouble that the whole series has been leading up to. There are some major setbacks along the way and a few very big shocks in the course of the book. The very end felt as though we were getting a set-up for a new book (series?) about Ultimate... we'll see, I suppose.
Anyhow. My one quibble with the book was the pacing of it -- it felt uneven, and I had a little trouble during the slower sections with maintaining interest in the plot as a whole. It almost felt as though the huge action-packed beginning should have been a part of the second book, so that we could have begun this book with the gentler-paced training & preparation section that, for this novel, was the front-middle of the book.
Lots of superhero action (in space!), and it's good to see the good guys get their act together and figure out who the real enemy is. Worth reading and an apt conclusion to a very fun superhero sci-fi story!