There's much speculation to who or what the antagonist of Halo 4 will be. People have said that our enemy will be the Forerunners, Precursors, and the Flood. The tenth terminal of Halo: Anniversary hints that the Forerunners will be our enemy in the upcoming game. In it, 343 Guilty Spark states, "Oh, but what I would not give to have even a single company of [the Librarian's soldiers] here right now. Oh, they would most certainly restore order with their trademark lethality. Although, that would mean [the Didact] would have to be here too, and without the Librarian around to temper his rage, well, these Reclaimers might almost prefer the Flood." This possibly hints that the Didact, the commander-in-chief of the Forerunners, will return and exact vengeance against the UNSC and Elites for the destruction of Installation 04 and the irreversible damage to the Ark.