In a dystopian world where humans are thought to have died out, the animals have gone all Animal Farm. Wolves are the rulers of this landscape, controlling boundaries and determining which predators are allowed to stay in their territory. The wolves' control stems from their strength, the fact that they're pack-based (there's a lot of them) and that they helped kill off the last humans, decimated by an infection and who knows what else. All the wild animals have serious contempt for Faithfuls, basically pets.
The bears have an uneasy truce with the reigning wolf pack in the area. Casseomae, an old female bear, is chatting with a rat, Dumpster, one day, having just saved him from some hungry coyotes, when something crashes to the ground nearby. Inside the thing are some of the Skinless (aka "Old Devils" or humans). The crash has killed all but one, a Skinless cub. Casseomae's mothering instincts kick in and she determines to save this creature, which every other animal in the forest wants to kill, except for Dumpster and later a dog named Pang. This odd team works together to save the child.
I never really got over the sense of strangeness as I read this. In no way is it bad, and I think the concept is fascinating, but it never really worked for me. Partly, I think that this is largely because it doesn't seem to be targeted at a particular age group. It's being marketed as middle grade, but I question that somewhat. The fact that the main characters are animals, and the child's age, which is indeterminate but seems young, would recommend the book to children. However, the violence of the story (especially since it's animals being hurt) would lead me to think it would be best for older readers, who might not be so interested in an animal tale.
The Prince Who Fell from the Sky is rather reminiscent of Ice Age, although humans are the ones dying out in that one. Even the main character grouping is fairly similar to Ice Age: child, bear (to replace mammoth - able to carry others and fight), rat (similar to the sloth in usefulness physically, but Dumpster is also a compendium of knowledge), and dog (not as useful as the sabretooth I'll admit). It's kind of like a dystopian mashup of Ice Age and The Incredibly Journey. So if that sounds appealing to you, definitely check this out.