First is The Sixty-Eight Rooms by Marianne Malone. In the Children's Gallery of the Chicago Art Institute there are the Thorne rooms, 68 miniature rooms, each of which is designed in the style of a different historical period. This book imagines what if you had a key that made you shrink so that you could go inside each room? And as you went through them, what if you discovered other people had also visited and maybe left something behind? This sounds like a really fun read to me.
Second is Suddenly in the Depths of the Forest by Amos Oz. In a village, all the animals disappeared long ago. Only one old man, and a young teacher will talk about animals with the children, it is like no one wants to talk about it. There is one little boy who really gets into the animal stories, then disappears. Two girls, Maya and Matti decide to explore the woods around the village. There are dangers, something called Nehi, who is mountain demon. They find the boy in a cave, but also find a place where there are lots of animals. But is also the home of Nehi. Turns out Nehi used to be a boy in this town who was mocked and treated horribly. He has stolen all the animals. They must try to find out how to get them back.