The other side of the sky

"Prince North's home is in the sky, in a gleaming city held aloft by intricate engines, powered by technology. Nimh is the living goddess of her people on the Surface, responsible for providing answers, direction--hope. North's and Nimh's lives are entwined--though their hearts can never be. Linked by a terrifying prophecy and caught between duty and fate, they must choose between saving their people or succumbing to the bond that is forbidden between them"--OCLC.