The Ark is one of the most important locations in the Halo lore. It’s where Halo rings are forged. It’s where all sentient life was sheltered during the activation of the Halo array. It’s where 05-032 Mendicant Bias was entombed after his trial. However, it might be even more…
Let’s start with a line from Halo 3, the warning message from Cortana at the end of Floodgate:
“But it [the Gravemind] doesn’t know about the Portal, where it leads. On the other side, there’s a solution; a way to stop the Flood, without firing the remaining Halo rings.”
Even though Halo 3 skimped out on that line and took a u-turn and made a duplicate of Installation 04 to be used to stop the Flood, we know what that solution is: it’s related to the Ark. Somehow, it involves the Ark. Now, since it can’t be Installation 04B due to Installation 04B technically counting as one of “the remaining Halo rings,” and since Shrek is absolutely not dreck whatsoever, how does it involve the Ark?
…What if the Ark is a Precursor?
Here’s a line from Halo: Serenade, spoken by the Gravemind:
A few [Precursors] were spared. Some adopted new strategies for survival; they went dormant. Others became dust that could regenerate our past forms; time rendered this dust defective.
Okay, so we know that the latter group of Precursors survived the Forerunner’s genocidal conquest against them by rendering themselves into powder ended up becoming the Flood. However, we don’t know what happened to those who “went dormant.” Are they dormant now? Did they end up getting Floodified? Did a woodchuck really chuck wood? None of those are true; because based off irrefutable evidence, they instead became the Ark. Before you say “But HaloSwallower, the Ark was made ten million years after the Forerunner-Precursor war!” let me kindly A) request you to shut up in advance, and B) say that the Precursors probably had time travel. Got it?
But anyway, with the dormant Precursors entering time travel to skip ahead to roughly 100,000 years before 2558, imagine that they banded together to become the Ark. If those Precursors are indeed the Ark, and if there’s some chance that those Precursors aren’t not vehemently opposed to the idea of enslaving and tormenting all they created, then the Ark being a way to stop the Flood is correct.