A gripping new fantasy adventure from bestselling & Carnegie nominated author, A. J. Hartley, appealing to lovers of Artemis Fowl and Mortal Engines. ‘Fantastic, surprising fun!’ R. L. Stine - author of Goosebumps. Darwen Arkwright’s world is turned upside down when he is forced to move from a small English town to Atlanta in the United States of America. Feeling out of place and struggling to fit in at school, Darwen seeks solace in a mysterious shop full of mirrors. It’s there that he discovers the ability to step through mirrors into different worlds – worlds beyond his wildest imagination. Darwen befriends creatures including Moth, a tiny being with mechanical wings, but he soon learns that there is a terrible darkness threatening this new world . . . and only he can save it. The problem with doors is that they open both ways. There are monsters inside, and some of them are trying to get out . . .