From the introduction:
Cloud City has always operated on the fringe of the law, but its tibanna gas mining has kept its Baron Administrators wealthy and powerful enough to preserve the city’s autonomy. Even Palpatine’s overreaching galactic empire has kept its hands off of the city’s not strictly-legal operations, making the Bespin city something of a haven for ambitious entrepreneurs, gamblers, and miscreants.
However, rumors have begun to spread of Imperial transports landing in the city. Some even report Darth Vader himself has been meeting with Baron Administrator Calrissian. Tensions are running high, and the city of six million waits on edge. Is it time to pick up and leave the planet, or is there time for one last score?