If you haven't read The Iron Queen yet don't even read the blurb...seriously, just don't read it! I'm going to try not to spoil anything with this review, but I might not be able to refrain from spoiling bits for the earlier books...I'll try though. 
 I think the biggest change between The Iron Queen and The Iron Knight is quite obvious...this one is NOT in Meghan's point of view, instead, it's in Ash's. I know lots of people were worried about Ash losing his mystery and all that, but honestly, I was never worried...Ash is even a mystery to himself ...seriously. haha I loved getting to read an entire book written in his POV. It only made me love Ash more. I loved getting to know his thoughts, and getting to see things from his side of the story. It was incredibly interesting and I think Ash managed to maintain his mystery...although I feel like I know his feelings for Meghan a lot better, which just made it even more awesome. Ash has always been able to make me swoon...honestly, I'll stop reading a sigh, no joke...so getting a whole book from his POV was a dream come true. Plus, I'm pretty glad that the story didn't actually end up being finished with The Iron Queen...as much as I loved that book, I think I would've been a bit upset if it ended there. :P 
 If you've read the other three books, you already know the characters, so you already know who you love and maybe some who you didn't love...but I'll mention them anyway. Ash, Puck, and Grimalkin, of course, are in The Iron Knight aplenty! The Big Bad Wolf and some other characters also pop up. The Wolf and Grim are hilarious together...seriously it's like Puck and Ash's banter, but they're animals...plus cat and dog jokes, that good stuff. I just mentioned Puck and Ash's banter...and I loved it in this one, I also loved getting to be inside Ash's head when he'd think about his past with Puck...or just think about Puck in general. It was interesting to get to see their relationship from the inside rather than just in passing through Meghan. Overall, the characters were fantastic in this one...as always, Julie always writes fantastic characters. :D 
 If you haven't started this series yet, then I'm just going to say right now that you should definitely go out and start it. If you're unsure, borrow the first book, The Iron King, from the library, and once you're hooked you can get your hands on the other books. :P 
 I'd recommend this one to fans of the series...although I'm sure by now most of you have read it already. :P And if you haven't started The Iron Fey series yet, then I recommend it to anyone who loves stories about the fey, stories with awesome heroines with some fabulous leading men, and anyone who's a fan of fabulous one-liners and banter....also, if you're a sucker for a forbidden (or even maybe impossible) romance you'll love this series. :)