“StarCraft: Ghost took place in the fictional universe of the StarCraft series. The series is set in a distant part of the galaxy called the Koprulu Sector and begins in the year 2499. Terran exiles from Earth are governed by a totalitarian empire, the Terran Dominion, that is opposed by several smaller rebel groups. Two alien races discover humanity: the insectoid Zerg, who begin to invade planets controlled by the Terrans; and the Protoss, an enigmatic race with strong psionic power that attempt to eradicate the Zerg.

Ghost took place four years after the conclusion of StarCraft: Brood War, in which the Zerg become the dominant power in the sector and leave both the Protoss and the Dominion in ruins. The game followed the story of Nova, a young ghost agent—a human espionage operative with psychic abilities—in the employ of the Dominion.”

- Source: Wikipedia