Whisperworld

Their voices are all that remain.
Julia has never seen what lies beyond Angel City. And why would she? The Wrath of God destroyed the old world, leaving only endless deserts and terrible sandstorms that can flay the skin from any human caught outside the city walls. Only the Tear, a vast, strange black sphere at the heart of her home, protects the people of Angel City. No one knows what it is or how it works, but if Julia listens closely enough, she can hear the Tear whispering…
But now the sphere is failing, falling silent, and not even the Gardeners who care for it know why. And when one of those Gardeners is murdered, Julia and her partner, Zach, are summoned to investigate why.
Their search for a killer will take them from Angel City's crumbling skyscrapers to the salt flats of the Pacific Desert. But what they find goes far beyond the murder of one man and threatens to wipe out the last remnants of civilization. Perhaps Zach and Julia can save their city - but first, they have to save themselves.