Dark forces combined to bring her under the sway of the zerg Overmind, but the same courage and tenacity that she had shown as a ghost, and later as a rebel against the Confederacy, brought about her dominance of the alien sentient. Now she holds the reins of the Swarm and commands an innumerable army of monstrous creatures poised to sweep mankind from the Koprulu sector.
Sarah Louise Kerrigan discovered the strength of her latent psionic gift as a young girl. An innocent flash of childish anger at her parents resulted in massive cerebral hemorrhaging and a horrific death for her mother. Her father would only repeat one thing over and over again in the ensuing years: “I saw her head come apart.” This gruesome event alerted the Terran Confederacy to her powers, and she quickly became the focus of the fledgling ghost program. Because she had reached unheard-of scores on psi-evaluation tests, her abilities elicited a complete readjustment of the scoring system so that she could be properly measured. The remnants of her humanity were stripped from her, and Kerrigan was designated Ghost Number 24601.
Following her emergence from the ghost program, she became an unstoppable assassin for the corrupt Confederate government. It was her assassination of the independent senator Angus Mengsk that brought her to the attention of his ambitious son, Arcturus. At first wishing to extract revenge from Kerrigan for his father’s murder, Arcturus soon realized that she was much more useful as a weapon against the Confederacy. After rescuing her from a clandestine experimental facility, he removed her neural inhibitor and used her restored memories to build righteous anger against the government that had abused her. Kerrigan and Mengsk became allies.
She was running a mission on Antiga Prime when she first came across one-time Confederate marshal Jim Raynor, a new recruit to the Sons of Korhal. He disapproved of her lethal dealings with the Confederacy, but the conflict between the two soon grew into mutual respect, admiration, and even… something more. Kerrigan and Raynor ran several secret missions together before Mengsk’s revolutionary movement brought them to Tarsonis. Even Kerrigan’s jaded sensibilities were shocked when she learned what Arcturus had planned for the Confederate capital world: the placement of psi emitters to lure the zerg to one of the most densely populated planets in the sector. It would result in the death of almost every living thing on Tarsonis. Voicing her opposition, she nonetheless set about loyally fulfilling her mission to protect the hive clusters from a mysterious new alien enemy, the protoss. Mengsk would take advantage of that loyalty, abandoning her to die on Tarsonis when the mission was complete. He couldn’t run the risk of having a powerful weapon like Kerrigan running loose in the shadow of his new government, and he couldn’t resist the chance to claim some vengeance long overdue. This betrayal enraged Raynor; he left the revolution, swearing revenge.
Little did Arcturus Mengsk suspect that he had just succeeded in arming the zerg against him.
The zerg Overmind sensed Kerrigan’s formidable psionic powers and desired to adapt this new weapon for the Swarm. Bringing all of the evolutionary strength of its genetic skill to bear upon the one-time ghost, the Overmind transformed Sarah Kerrigan into an unstoppable combination of psychic ability and biological deadliness: the Queen of Blades was born.
Not wanting to hamper Kerrigan’s intellectual and strategic brilliance, the Overmind left her a degree of individual will that differed from its cerebrates. It was this freedom that allowed her ambitions to rise, and before long, the Queen of Blades conquered her cerebrate kin and took charge of the Swarm when the Overmind was slain.
Now Kerrigan moves the zerg toward an unknown future. Ancient prophecies foretold her coming. The sense and meaning behind these prophecies are vague, but make no mistake: countless billions of lives are bound to the destiny of Sarah Kerrigan.