Every Heart a Doorway by Seanan McGuire

EVERY HEART A DOORWAY gives readers a peek into the cracks and doorways of magical worlds. Worlds of wonder and whimsy, and then asks: "What if you were to tumble into one of these enchanting realms?" EVERY HEART A DOORWAY tells the story of what happens after, the Ever After. When the children who have tumbled down the rabbit hole or entered that wardrobe are no longer wanted, their magic all used up.