The Invisible Library does not have a fancy cover but it is simple and elegant and I am a sucker for any book that has the word "library" in it. So I had to pick it up! And I'm so glad I did! This is not a YA book but I loved it none-the-less. Book Review: Irene is a junior librarian for THE Library. This library exists on its own, outside all the countless alternate worlds. Irene travels to different alternates on assignment to collect certain unique copies of books..occasionally, by any means necessary. Sometimes this is an easy task, sometimes not. For this mission, she must go into an alternate that is infested by Chaos. To make matters more complicated she has been assigned an apprentice that is keeping something from her.