Earthman, come home

When the cities left Earth, they exchanged a simple environment for one of constant, sometimes shattering, change. The Universe was littered with cultures in every conceivable stage of development. Only the iron hand of the germanium-backed economy and occasional interventions by the Earth police imposed some kind of order on the spaceways. Even John Amalfi never got used to the constant crisis of life on board and "Okie" city. And he had been mayor of New York for nearly five hundred years now...