I liked getting to better know Phin, his abilities were impressive. Readers were kind of left hanging about what kind of relationship he had with Joseph in the previous book. Their relationship development in this book, I wasn't really too happy about. It didn't grab my attention and I felt the chemistry between the two were lacking. When Phin and Jo mend the rift in their relationship and the truth comes to light, it's anti-climatic.
Plot-wise the progression wasn't too bad. Reader's get to see what happens when individuals at Glitnir becomes aware of magic users. New things are revealed and plans of action are kind of made.