From Adventure Introduction:
The Gem of Alderaan is the eighth adventure in the Dawn of Defiance campaign, which will take heroes from 1st level all the way through 20th level in a continuous storyline designed to give players and Gamemasters a complete Star Wars Roleplaying Game Saga Edition experience. This adventure begins the third act of the campaign, which consists of three adventures: The Gem of Alderaan, Sword of the Empire, and Jaws of the Sarlacc.
About six months have passed since the last adventure. Over the
course of this adventure, the heroes will infiltrate a high society gala, play high-stakes games of sabacc, and fight alongside Imperial stormtroopers to defend against hijackers bent on capturing a train full of dignitaries. The heroes should start The Gem of Alderaan at 15th level and reach 17th level by the conclusion. With some modifications, this adventure can also be used as a stand-alone scenario or as part of your existing campaign.