Darker's story is revealed over the course of the game as information gathered by reconnaissance. The people of Delphi are not militarised, having never had reason for military action, and so technology for combating the Halon menace is developed over the course of the game. The Halon people are revealed to be invading in order to expand their cities away from the light side, which they have polluted beyond the point where it can sustain life. Eventually Tolly pilots a Halon craft to the light side of the planet, where he destroys the Halon aircraft factories.