This is going to be a long read so be prepared. I’m a Halo fanatic, literally a Halo freak. I was watching Halo Legends tonight because I wanted to watch it again. Of course Origins is the first episode in Halo Legends. I also pay attention to every little detail in every Halo game as it pay point out something for the next game in the Halo series.
Now we all know the planet at the end of the Halo 3 legendary ending is nothing other then the Forerunners homeworld itself. We all thought it was Onyx the Shield World but the planet from Origins pointed to the symbol on the planet from Halo 3. Now the ending of Origins part 2, it takes us back to the Forerunners homeworld. I know this because the piece of a cryochamber door is on the ground, which a Flood infection form crawls out of. Now 343I hinted of a threat that will threaten the Universe as a whole. My theorys added up to somehow Marines found the Forerunner homeworld and dived into Forerunner technology too much and it drove them mad. I know of this from a YouTube video and no I’m not posting it here so you can go find that yourselves.
Now what greater threat is greater then the Flood? It can’t be the Forerunner or the Precursors themselves because we’ve never seen the Precursors and from Origins, we know the Forerunner destroyed themselves in an effort to make them the last victims of the flood. But they didn’t destroy the flood entirely. The Flood appear again in the first Human Vs Covenant war we see in Origins. The scene at the end of Origins part 2 can only be the Forerunner planet. We see a Spartan get handed a AI chip that can be inserted into a helmet from a Flood form itself. We don’t know if that Spartan is John 117 himself, but it could be because John is headed to the Forerunner planet in Halo 4.
The Flood can appear again at any time. We’ve seen proof of this in the Human Vs Covenant war scene in Origins. So can it be possible that the Flood somehow back to the ruined Forerunner planet? There is no greater theat that can be aimed at the galaxy except the Flood. We destroyed the Flood in Halo 3, but we still don’t know where the Flood originated from. We also don’t know if there can be more Flood forms out there.
So here my theory. We travel to the Forerunner planet in Halo 4. Along the campaign, we discover that the Flood presence exists on the Forerunner homeword and that it is attempting to use the Ark’s portal to travel to different parts of the galaxy to infect everything it can. After all the Ark transported the Halo rings to different parts to the galaxy to destroy all life. We know the Flood absorb the intelligence of those they infect. What’s saying that they’ve accquired the intelligence to operate the Ark? So my conclusion is that we make a last stand against the Flood. But not the Flood we’ve seen in Halo 3 or Halo 2. The Flood forms that the Forerunner themselves encountered. Our goal in Halo 4 may be to destroy the Ark itself. I’m aware we destroyed the Ark in Halo 3. But what facts do we have that the Forerunner’s didn’t have a 2nd Ark? We know the Ark was created on their homeworld. Whats to say that the one that used to transport the Halo rings isn’t there still? The Ark we see in Halo 3 isn’t anywhere near the Forerunners homeworld and the portal is a mechanism that the Ark has. It could be possible that another Ark exists on the Forerunner homeworld.
This is just my theory on what may be the plot to Halo 4.