When Billie and her baby brother, Bix, neglected children of rock stars, stow away in their uncle's car, they find themselves transported to the Borderland, a world where animals talk. When Bix is kidnapped by the evil Kingfish, Billie must try to rescue him, with help from a shady crow and a talking wheelchair. No one would ever accuse the father-and-daughter team of Jenkin and Jenkins of lacking imagination, but there's little evidence of discipline or focus anywhere. The endless parade of invention for its own sake rapidly loses control; at first diverting, the action becomes numbing, and readers won't care enough about the characters to keep traipsing after them. Truly original creative turns show promise, but can't compensate for a wild-card plot.