I really liked "Shadow and Bone" and read the Wikipedia summary before starting this second book in the series to refresh my memory. However, I just couldn't remember enough. I know it's tricky for authors when they write a sequel - too much rehashing gets boring, but in my case, not enough took away from my enjoyment. Presumably the primary audience of teenagers do remember the details better and it hopefully isn't a problem. 
 Otherwise, there was plenty of action and angst, and I liked how the author made Alina's role and her feelings about it so complex. The plot moved forward nicely, but I won't be finishing this series.