Awesome Oz-esque portal fantasy. A couple regular kids get ripped away from their regular lives by weird coincidental road construction and a wall that shouldn't be there.

The story detail's Zib and Avery's improbable adventures through the Up and Under searching for their way home.

I listened to the audiobook and the narration by Heath Miller was fantastic on top of prose that is nearly lyrical but not to the point of being dense, just the right word with the right feel and the right sound at the right time.