Synergy on the Galactic Tunnel Network — E.M. Foner

The New York city-state has a problem, and it's not just gryphons eating drones..Earth is holding its first world's fair in over a century and the nascent Human Empire is building a pavilion. The non-human species of the tunnel network are worried that their tourists visiting Earth will fall victim to charity scammers, while the city-states and legacy nations of Earth are worried about their exhibitions being outshone by alien business operating on Earth.