So you have a door, getting in and you go into an entire different world? Who doesn't like that?
I find the strongest part of the story, this new world i mentioned. It's so well created, with its own lore, people, ideas, magic and so well explained it's just feel so real. My favorite parts were when Charlotte was over there. And for the sake for it, the book deserves a read. No it's not the only good thing about it, but it's just so good.
Of course except Charlotte who is our main heroine there are others too. Okay wait..let's talk about Charlotte first. She is one of the strong girls, i didn't really connect with her and there were times she annoyed me with how easily she believed and followed Calvin but she is okay. My favorite character was her brother Kevin. He is older, and who doesn't love an older brother who is overprotective about his little sis and does everything about him? Maybe it's because i have a soft spot for that kind of things but i definitely liked his presence in the book.
In the end you have a book, with another world. Something we've seen before but still feels new and is quite enjoyable in here.