Nafash had taken the brood there, seeking to rebuild the brood's numbers. She hoped the cold, harsh climate would enhance her brood's resilience. The harsh conditions of the planet has evolved her brood to new heights of aggression.
Her ploy failed, and the protoss forces there killed her, though they had to drive her out of positions that she had prepared in the ice valleys. Sarah Kerrigan arrived on Kaldir seeking her brood. They found Nafash's body and the feral remnants of her warriors, inducting the survivors into the Swarm.