The main reason it didn't quite grab me was the relationship with Meghan and Ash, it just wasn't deep enough for me - saying that, there were a lot of other things in the book that made me want to read the rest of The Iron Fey series (that, and I've heard nothing but rave reviews about it).
Ignoring the novellas, The Iron Daughter is the second book in The Iron Fey series and, in my colloquial opinion, absolutely decimates The Iron King! It's just better. Better writing, better dialogue, better storyline, better relationships. Better in every way.
I'm so glad I gave this series a chance because, halfway through book 3, The Iron Queen, it's turning into something pretty great. But anyway, I'm getting ahead of myself.
So, The Iron Daughter starts off with Meghan a prisoner by choice in the Winter court. Ash refuses to acknowledge their relationship/feelings and she's freezing all the time. I won't give away any spoilers but the action starts pretty quickly in this book and so does the development of Meghan and Ash's love.
I believed it a lot more this time around. Kagawa does a good job of presenting Ash's torn feelings of guilt and regret over Ariella's death and at the same time really makes you feel bad for Meghan as she sees that. This is what I wanted from The Iron King, more depth and more conviction to the relationship; and throw in the involvement of Puck and good lord, its a goodun. (Desperately trying not to give away spoilers).
Aside from the love triangle going on, we meet a couple of new characters, Leanansidhe and Paul probably being the most significant newbies, Ironhorse being a very significant oldie, Grimalkin sticks his tail back in, and our contagious friend Virus is back, too.
We get a little more insight into Meghans abilities and her connection to Machina and the Iron Realm. It's pretty easy to guess the outcome and therefore the premise of The Iron Queen, but if you hadn't guessed it half way through the book, a few choice words from Ironhorse will solidify it towards the end.
Overall, the mix of characters, scenery, and storyline make this much more interesting that the first book in the series. The Iron Daughter still leaves a few pretty big, unanswered questions lingering, and if they aren't enough to make you read book three, the enduring sure as hell will!
I'd give this one a 4.5/5, much more interesting than The Iron King and I'm getting the feeling the series only gets better.