Note: This is not a stand-alone game - you need Saboteur, the base game, to play.
From the rules:
In this expansion, there are new roles for the dwarves to take as well as new action and path cards that await the players. There are the usual gold-digging dwarves, but now they are split into two teams: the Green Team and the Blue Team. As before, the gold diggers want to drive a mine towards the treasure. But this time, they‘re not on their own, but have to co-operate with their team mates in order to succeed.
One of the new characters is The Boss. He wins whenever the Green or the Blue Team wins, but always gets one Gold Piece less than them. Then there is The Profiteer, who, true to his name, doesn‘t just win when the gold-diggers (Green or Blue) win, but also when The Saboteurs win. However, he has to be content with two Gold Pieces less. The Geologist doesn‘t care much for treasure hunting. He is after the valuable crystals in the tunnels. For each visible crystal, he receives 1 Gold Piece. Play the expansion over three rounds (like the base game), and in the end, the player with the most Gold Pieces wins.