Some primal Zerg, however, eluded and remained independent constantly evolving creatures. On Zerus, Kerrigan learns that a fallen Xel'Naga named Amon was responsible for making the Zerg what they are: A warring swarm, bound to a single overriding will. Zeratul visits Kerrigan and advises her to regain her powers by traveling to Zerus, the original homeworld of the Zerg. On the frozen planet Kaldir, she annihilates the local Protoss forces, reclaiming the local brood and evolving the swarm to survive in harsh climate.
After a change of heart, she allows the wounded and the unarmed to evacuate. Kerrigan, in a rage, destroys a Dominion command fortress and kills its commander, General Horace Warfield. On the volcanic planet Char, Kerrigan subdues a renegade brood before attacking the occupying Dominion forces. Enraged, Kerrigan returns to Zerg territory to retake control of the swarm and overthrow the tyrannical Dominion. The Hyperion escapes, but Kerrigan remains behind to locate Raynor, only to hear a Dominion newscast announcing that he has been captured and executed. Kerrigan and other residents escape to the flagship of Raynor's Raiders, the Hyperion, but Commander Jim Raynor is cut off by the Dominion. Following the events of Wings of Liberty, Terran Dominion forces attack Sarah Kerrigan and her allies in a research facility in the territory of the Umojan Protectorate.