Swap Night on Union Station

Kelly is chosen for an honorary exchange with the other tunnel network ambassadors on Union Station in which all participants pledge to represent the interests of the host species for a week. But the aliens have been playing this game for hundreds of thousands of years and have their own ideas about how to best serve humanity.
Swap Night on Union Station is the nineteenth book of the EarthCent Ambassador series. New readers should start with the three-book bundle, Union Station 1, 2, 3.