'We increased the bounty on angels today,' my father said. He was shielding his eyes as he squinted up through the ground window at the red, dying sun. 'Five thousand pecs for a healthy woman or child...' Humanity has splintered. Over millennia, the Avians of the Clifflands have learned to fly with wings of sky metal. The Subterraneans venture to the surface only to farm in vast glass domes. Between them lies the boundless and savage Wilderness. Suspicion and hostility between their cities shadow every aspect of life in this post-apocalyptic world. Icarus is a Seraphim, rare and destined for greatness. When he is sent on a deadly mission to far-off Subterranean Newtopia, his people's hopes weigh on him as heavily as the wings on his back, or the bounty he must capture. Velvet is an outcast, shunned throughout Newtopia and protected only by her domineering father's influence. Unwilling to bend to the patriarchal tyranny of the Elders, she dreams of freedom. Meanwhile, shadowy forces are plotting to overturn the long-simmering stalemate, unleashing conflict that will usher in a new and even darker world order. Threatened with a war that will end their people forever, Icarus and Velvet must struggle to survive. Flung together by fate, they must forge an alliance — or die.