"After the Created, came the onslaught."
When the devastating and costly war against the Created came to an end, due to the lack of faith in the UEG as a whole the insurrections rose up to claim independence. Thus, the UNSC was left unable to recover from the losses and instead fight against them, with even some insurrections such as the Reikist Initiative becoming strong enough to openly challenge a dying UNSC.
At the worst possible time, the parasite returned with a vengeance, the Flood began it’s onslaught on a divided Humanity and the rest of the galaxy. Now in 2576, the situation has become desperate enough to where even one of the UNSC’s most feared Spartans has returned. Foley Lockhart heads Spartan fireteam Verdict, who will be the scalpel to cut into the enemies of the UEG and Humanity.
But it is only a matter of time before everything comes crashing down. Halo: Onslaught Chapter 01.