I continue to be enamored with this series. I think the writing is really solid; I feel like I know the recurring characters well at this point, but the new characters, including the new villains, continue to be well developed and keep things fresh. The plot is fast paced, and full of twists, so it really kept me guessing all the way through, just like her books have in the past.
I really like that Lydia's character continues to develop through the series. We learn more of her history and backstory, and I personally felt like it helped me connect better to her character. This series continues to be solid, yet still surprises me and catches me off guard. Which is a very good thing indeed.