Yeah, in the first chapter of StarCraft, she was a ghost working for Arcturus Mengsk and she started a romance with the main protagonist, Jim Raynor. Arcturus Mengsk basically put her in the most dangerous position possible, then didn't rescue her, so she got infested by the Zerg. She then became the primary antagonist after the leader of the Zerg, (the Overmind), was killed. In the expansion to StarCraft, it was basically all about her struggling with others who were trying to lead the Zerg, but in the end, she became the undisputed ruler.
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