Queen City Jazz

Queen City Jazz is a science fiction novel by Kathleen Ann Goonan, published in 1994. It takes place after a plague of engineered organisms has broken the population that once lived in the nanotech cities, leaving small settlements like the farm where Verity has grown up, and it follows her out of that shelter and into the ruined city of Cincinnati.

Verity's world is small and her only close friend in it is Blaze, so when he is shot and left dying she does the one thing available to her and puts him inside a nanotech cocoon. Then she leaves for Cincinnati, the Enlivened City, which the people around her know mainly as a story about a place where the dead can be brought back, and the journey there is the whole of her plan.

Cincinnati is stranger than the story. It is a city of bio-engineered bees carrying information along the streets and enormous flowers bursting from the tops of strange buildings, and it is still reliving the fantasies of the person who made it. Verity finds that its creator has died without a successor and that the city has to be governed by someone, which leaves the visitor from the farm as the only candidate it will accept.