Book Two suffers from most of the same weaknesses I mentioned in the review for The Alchemyst: the odd sort of dryness to the writing (don't know if that's quite the word I'm looking for, but no other word is really coming to mind) that causes the book to feel rather dull in places, even when it's during a scene with lots of action, and the bad habit of repeating facts that we've already established over and over. First, we need to relisten to all the main points of what occurred in The Alchemyst, which I find unnecessary, since a reader's enjoyment of this book is going to be quite hindered if they didn't read the first book to begin with, and then, everything that we learn within this book is hammered into our heads time and time again. The constant reminding of auric smells, or powers that everyone can use. This isn't helped when someone will make a comment about something they need to do or referring to some immortal's abilities in a roundabout way, but which the answer for is glaringly obvious to the reader (because, again, due to REPETITION), and Sophie or Josh will act all "Durrrr, what you mean?!?!?", even though it should be obvious to them too.
Speaking of the twins, Josh annoyed the hell out of me in book one while Sophie was alright. By the end of book two, I now hate them both. In fact, this is supposed to be a book series about Nicholas Flamel, so the importance constantly place upon Sophie and Josh, giving them the right to be the Spotlight-Stealing Squad makes things all the more unbearable. It's a young adult series, so of course the main characters need to be teenagers, right? Actually, I think the series would've been a lot stronger, and no less entertaining to youths, had it actually focused more on Flamel and his adventures. (Truthfully, though, I imagine if an author did try to sell a YA story with no minors in it, most publishers would refuse to buy it, saying it needs kids for kid readers to identify with, or some BS like that.)
Though to be honest, so far the only characters I particularly like and enjoy seeing the adventures/antics of are Scathach (sometimes), Machiavelli, the spider elder (hey, the narrator gave it this adorable lisp, okay?), and Perenelle...though Perenelle herself sort of falls into the "too perfect" category. (She's incredibly strong, more so and more worthy of fear than Nicholas, so far she hasn't made any serious blunders, she can constantly pull out some brand new trick from her ass when she's in a dire situation, and Nick himself constantly bemoans her not being there, because "Perenelle would know what to do" in even the most bizarre situation.) Really now, we already know all these non-humans and immortal humans have ridiculous amounts of power. They can still have some actual flaws, too.