Clockwork Heart

"A steampunkish romantic fantasy set in Ondinium, a city that beats to the ticking of a clockwork heart. Taya, a metal-winged courier, can travel freely across the city's sectors and mingle indiscriminately among its castes. A daring mid-air rescue leads to involvement with two scions of an upperclass family and entanglement in a web of terrorism, loyalty, murder, and secrets."