The Last Universe
Fourteen-year-old Susan and her wheel-chair-bound brother Gary live in a strange house far from the ordinary bustle of their suburban community. In their sprawling backyard is an overgrown garden planted by their late uncle and tended by a mysterious gardener. Gary, who seems to be dying of an unknown illness, insists on being wheeled around the garden everyday by his sister. On these excursions, they notice impossibly large plants and exotic flowers growing up overnight and, in the heart of the garden, a hedge maze that holds a secret. This quantum garden is not ruled by the laws of the macro world, and the longer Susan and Gary explore, the more they risk returning home very changed; if they can get home at all.
William Warner Sleator III (1945–2011), known as William Sleator, was an American science fiction author who wrote primarily young adult novels but also wrote for younger readers. His books typically deal with adolescents coming across a peculiar phenomenon related to an element of theoretical science, then trying to deal with the situation. The theme of family relationships, especially between siblings, is frequently intertwined with the science fiction plotline.