Liesl lives in an attic bedroom, locked away by her stepmother.He only friends are mice and shadows, until a ghost appears from the darkness. Po comes from the Other Side, where the dead go. Both are lonely, but together they are less lonely. The same night, the alchemist's assistant, Will, accidentally mixes up a box with the world's most powerful magic with one that isn't as extraordinary. Will's mistake has tremendous consequences for Liesl and Po, and the three of them end up on a remarkable journey.This book was magical and hauntingly sweet and sorrow-filled. It was a journey through life and death, through truth and lies, through a dangerous world to fins the one place you can call home.After reading the book, I found the title a little misleading. Yes, it's about Liesl and Po, but it's also about Will. It's Will that continues the book after Liesl and Po's first meeting, even though he has no idea what he's done until it's too late.The trip Liesl and Po and Will make is so daunting, so dangerous (but they don't know that). All Liesl cares about it her father, about seeing him again, making everything right, escaping the attic. Once she's out in the world, nothing will ever keep her locked away again.The illustrations were wonderful, they added to the story, giving the characters more life. Like snapshots into their journey. I can't talk about this book without mentioning the artwork.When reading this book, I wondered whether or not it could be called middle grade or not. Considering the story, the characters, the journey, yes. Considering that it's 300 pages long and hardcover, I'm curious if some kids will see it and think it's too big or too long. However, I do see this as a book parents can read with their kids. If you've got any 8 to 12 year olds in your life, get this book and read it with them.A change of pace from the author's previous novels, Liesl & Po proved to be just as magical and moving. A welcome addition to the huge crop of historical fantasy (it has a vague historical feel to it, dusty from coal and wood fires) middle grade books with ghosts and magic.