Dark Portal

Dark Portal is about a group of school aged mice that are lured behind that face of an ancient grill that they've been warned about since before they can remember. once through, their lives are in terrible constant danger. With rats and all manner of other creatures out to make a meal of them. but they stumble onto something much bigger than themselves and end up responsible for saving everyone they know because not a soul would believe them about the dangers down below, even if they could admit to going down in the first place
Dark Portal was actually an extremely interesting book. You would think that since the main characters are animals that the book would be childish but it wasn't. Also, the complicated additives of religion, and prejudice between the social classes are very interesting and somewhat ironic given that the main characters are animals.

Catherine Kendell