Sarah Kerrigan is a hero unit that appears in the missions "The Moebius Factor" and "All In." In "The Moebius Factor," Kerrigan will walk across a pre-destined path through the map, stopping to investigate empty buildings. The player must destroy the data cores before Kerrigan reaches one, or the mission is lost. Kerrigan cannot be killed and attacks the player if approached, so it is best to avoid her.