The storyline of StarCraft II will take place four years after StarCraft: Brood War, and will feature the return of a number of heroes and villains from the original game, such as Zeratul, Artanis, Sarah Kerrigan and Jim Raynor. Players will revisit worlds from the original game, such as Char, Mar Sara, and Braxis, along with new worlds, such as the jungle planet Bel'Shir. It has also been confirmed that the Xel'Naga, the ancient space-faring race responsible for creating the Protoss and the Zerg, will play a major role in the game.
Following the events of Brood War, Kerrigan and her Zerg forces are the dominant force in the galaxy, having annihilated the United Earth Directorate's Expeditionary Force, destroyed the Terran Dominion, and invaded the Protoss homeworld of Aiur. However, it has been revealed that after the conclusion of Brood War, Kerrigan retreats back to Char, despite having more than enough power to crush all resistance in the Koprulu Sector. In the four years leading up to the events of StarCraft II, Kerrigan has not been seen or heard from by any of the other characters, although her ultimate attack may come at any moment.
Arcturus Mengsk has been left to rebuild the Dominion, consolidating his power while fending off harassment from rival Terran groups. Valerian Mengsk, a character introduced in the novel Firstborn, will play an important role in Dominion politics, due to his position as heir apparent to the throne. Meanwhile, Jim Raynor, whose role in the events of StarCraft and Brood War have been marginalized by the media under the Dominion's control, has been reduced to mercenary status, and has been shown to be doing business with the "Moebius Foundation", a new faction which is interested in ancient Xel'Naga artifacts. Chris Metzen, Vice President of Creative Development, has emphasized that by the events of StarCraft II, Raynor has become jaded and embittered by the way he was used and betrayed by Arcturus Mengsk. Other new characters to the series include Tychus Findlay, first introduced in the StarCraft II teaser cinematic, a marine who will be a member of Raynor's crew, and Matt Horner, Raynor's second in command, another character originally featured in one of the novels.
Following the fall of Aiur and the death of their matriarch Raszagal, the Protoss have retreated to the dark templar homeworld of Shakuras. There, Artanis, a former student of Tassadar, is trying to unify the Khalai Protoss and the dark templar, who have nearly separated into a tribal mindset as a result of centuries of distrust. Zeratul, tortured over the murder of his matriarch, has disappeared to search for clues to the meaning of Samir Duran's cryptic statements regarding the Protoss/Zerg hybrids in Brood War's secret mission "Dark Origin".
