The Toyshop at the End of the World — Robert Brown

At the top of a dusty cellar stairs, two little girls sit listening at a crack in the ceiling. Chloe and Isabella live here beneath the floor, in a cramped and dreadful basement apartment, where they have cared for their sick mother for as long as they can remember - never told what they are hiding from and never allowed to leave. They sit day after day listening to the sound of happy children above them,  wishing for a different life than the life of fear and hiding they were born into. One day, the food stops coming. Desperate, they crack open the hatch door. They creep out to find themselves in Herr Drosselmeyer's Toys, the most fantastical toy shop in the world, and the final project of the great Doctor Calvin Calgori. Calgori - the very man who had invented time travel and thinking automatons! Each night the girls sneak out to play with, and befriend, the marvelous toys - until they learn why they've been forced to spend their lives in hiding.