Donnelly hooked me big-time with Revolution (still one of the most powerful books I have ever read), and I have hung with her as she has bounced from one genre to another ever since. I read somewhere that she wanted to write for her own middle-grade daughter and her friends, which I think explains her plunge into the Disneyverse in the last few years.
I just finished "Lost in a Book," and like the Waterfire Saga, her last Disney project, she brings a level of depth and nuance that's rarely (if ever) seen in its genre -- in this case, movie spin-off books. "Lost" is an original story that expands on the Beauty and the Beast fairy tale (and presumably the new movie), but doesn't repeat it or contradict it. It's a completely different story set in the same world and with the same characters (plus a few new ones). It follows the lives of Belle (mostly) and Beast and the rest of the crew when they're offscreen, if you will -- away from the main storyline, and before the movie's big romance.
You can read the book description for the story, but the amazing thing to me is how much goes on: this is not a throwaway tangential plotline. It's a grand adventure, as the blurb says -- but more importantly, it provides a lot of backstory and inner-life action that flesh out Belle (and Beast) as characters. It adds a big dimension to the overall B&B story -- I'm guessing this new addition will become part of the main tale from now on.
And this is a Donnelly book, so there's a lot happening beneath the words on the page: big themes of love and death (actually, in this rendering, Love vs. Death -- literally!), coming-of-age, forgiveness, redemption, a love of books and literature (yes, Belle adores Shakespeare, Chaucer and Milton; A Northern Light fans will definitely see shades of Mattie Gokey in her!). But it's not heavy or academic -- it's an easy read and a lot of fun.
It's a kids' book, but like the best Disney movies, there's plenty going on here to engage and entertain the grownups. If you're a Beauty and the Beast fan (or a Donnelly fan) of any age, I think you'll love this.