City of a Hundred Rows, book 1: City of Dreams & Nightmare
Ian Whates2010

They call it the City of a Hundred Rows. The ancient city of Thaiburley is a vast, multi-tiered metropolis, where the poor live in the City Below and demons are said to dwell in the Upper Heights.
Having witnessed a murder in a part of the city he should never have been in, Tom, a lowly street-nick, has to run for his life through the City Below, Thaiburley’s unsavory basement world. Accused of committing the murder himself, he is pursued by sky-borne assassins, Kite Guards, and agents of a darker force intent on destabilizing the whole city. His only ally is Kat, a renegade like him, but she proves to have secrets of her own…