I read this entire book in one sitting and loved it! I need the third book stat.
I didn't give this book a full 5 stars just because I didn't care for the whole "love triangle turning into a love rhombus" aspect of the story. The central love triangle actually annoyed me much more than it did in the first book, also. Ergo, no 5 stars.
Other than that, this book was great. Juliet's ongoing struggle between the two sides of herself was sometimes hard to read. Even though her father is dead, the way he continues to influence her conscience and personality in general was equal parts realistic and disturbing. At the end of the first novel she has escaped from him and his creations. But it became clear throughout the course of this book that she will never be free of him because there is a part of him that lives within her, even though she generally chooses not to act on those urges.
This book had me on a total emotional roller coaster that really never happens while reading YA. Sometimes it happens with NA, but rarely with YA. I just care about these characters more and more as this series goes on. Even Lucy really grew on me throughout the course of this installment. I felt completely indifferent towards her going into this book, I honesty barely remembered her character from the first one. In The Madman's Daughter I did admire Lucy for standing by her friend after her fall from high society, but at the same time I couldn't imagine why Juliet would be friends with somebody so shallow in the first place. It became clear in Her Dark Curiosity that Lucy is actually a good friend to Juliet, and is a genuinely good (and surprisingly strong) person.
Juliet's relationships with each and every character developed so much throughout the course of this book. The interactions between her and the Professor and her and Elizabeth in particular were great warming to see. We obviously never had scenes between her and her mother, and so it was nice to see her have some normal and nurturing parental-type moments since her father was a total psycho.
I am so excited for book three, especially since the inspiration for that story was revealed at the end of this one. I'm not sure if it's mentioned in the synopsis for that one and don't want to spoil anything. It was a very unexpected and intriguing reveal.