More like 4.5 I enjoyed this book more than the 1st in the series. It reminds me of a mystery by other authors I used to enjoy, but started to find too predictable, cheesy, trite, and cliche. This series is gripping and moving but also very smart. Some predictions can be made, but overall things flow with a relative amount of twists, turns, and realizations that are logical and believable. The ending on this one was excellent, I couldn't stop reading. Can't wait for the third, but am sad it will be the last. I know I will be upset when I get to the end. 

Question: How is the storyline?
Answer: This series is gripping