As in Madeleine L'Engle's A Wrinkle in Time, math and science inform this mind-bending mystery about a girl who must work with the laws of the universe and trust the love of her family if she is to set her world right. It's the morning of Maisie's tenth birthday, and she can't wait to open her presents. Maisie is not a typical kid. What she wants most for her birthday are the things she needs to build her own nuclear reactor. But she wakes to an empty house, and outside the front door is nothing but an unsettling, all-consuming blackness--a shifted reality. Even for super-smart Maisie, these puzzling circumstances seem out of her control . . . or are they? A CLIP Carnegie Medal Children's Book Award Nominee "A heartbreaking, head-melting science fiction mystery from the superlative Christopher Edge."--The Guardian "[Edge] . . . has a magical way of distilling difficult concepts [like] relativity, gravity, time and space, infinity. . . .He weaves these ideas into a high-energy thriller."--The Times (UK) "Gripping, terrifying and eye-poppingly original. Grabs hold of your brain--then tugs at your heart." --Jonathan Stroud, author of the bestselling Bartimaeus Trilogy