On the anniversary of the release of Halo 5, as promised in my previous post “How to Hunt the Truth in Halo 5”, maybe it’s time to reveal what I believe to be the “solution” to the “Hunt the truth” Mystery in Halo 5. There is indeed a “hidden plot” beneath the apparent story of the Campaign. In another post, I will show how this all fits with the Trailers.
Spoilers ahead, so this is only intended for people who have completed the Campaign, and requires that you know the basic story anyway. But for those who have played the Campaign and still be baffled by it, I hope this will change your minds about Halo 5’s story and the Trailers forever. Enjoy.
(1) The Cover-Up
It’s NOT Cortana on Genesis, but a new AI, the ONI Cyberweapon “Cortana Mk.2”. Probably by offering a way out of spending the rest of her life in Jail (in Lore), ONI blackmailed Halsey into making “a new Cortana model” after Halo 4. This is as predicted by Cortana in Halo 4, it’s just the way the “new Cortana model” and Chief get “paired” was wrong. The rest of the “AI Revolution” is also faked as part of the cover-up, using hacked and remotely controlled AI’s. So, Cortana and the AI’s are all being framed as part of the cover-up.
(2) The Truth Exposed
Behind the cover-up, it’s actually ONI who are behind the Guardians. Perhaps at first they intended to blackmail independent Colonies with “If only you were under ONI Rule, we could protect you from Cortana and her Guardians”, and anyone who gave in and let ONI rule them wouldn’t get attacked by Guardians, “Proving how good ONI are at protecting them!” Yes, it was to be a good old fashioned “Protection Racket”. But if it fails, then Halo 5 just becomes an ONI Military Coup to crack down on the Rebel Colonies and their UNSC Defenders…
(3) Chief’s Character Development
After Cortana apparently dies saving him and the world at the end of Halo 4, Chief now discovers that ONI are trying to frame his dead best friend Cortana. This finally pushes Chief over the edge. His problem of “Am I a human with free will, or just a machine who just obeys ONI orders?” gets solved, as Chief decides he’s a human who needs to turn against ONI and their Machines. So, is Chief “Hero or Traitor”? He’s kind of both! A Hero to us and the UNSC, but a “Traitor” to ONI as he’s trying to stop their Military Coup with the Guardians…
(4) Janus Key & Artemis
The Janus Key is still missing, perhaps “out there” for Chief to yet find and use. To get round the missing Janus Key needed to find Forerunner Superweapons like the Guardians, ONI equipped Cortana Mk.2 with a version of Artemis, like Locke’s Intel Finder, to search through the Foreunner Networks to look for Superweapons such as the Guardians. This high-power Artemis causes the pulses seen coming out of the top of the Gateway on Genesis into Slipspace/ It’s also behind the Builder’s “Echoes”, and the Halsey Intel in Mission 1 reporting “Some sort of Echo-location, as if she’s looking for something.” That Cortana uses Artemis is also one of the pieces of evidence that this is an ONI plot.
(5) The Fate of the Real Cortana
Chief begins Halo 5 believing Cortana to have died. In Halo 5, he and we discover she kind of did. But, behind the scenes, before ONI got control of the new Cortana Mk.2, Halsey finds, repairs, and extracts the original Cortana. Redeeming her old Spartan-II tricks of replacing originals with clones, after Halo 4, we can now witness the real Cortana’s “Resurrection from the Dead”…
So, Cortana is completely innocent!Halsey extracts her and hides her in Sleep Mode in the capsule as anti-assassination insurance, to blackmail ONI back with “Anything happens to me, and the real Cortana and a copy of all the plans gets made public!” The term “both” in the Opening has more than one meaning. In the very next scene, instead of “both”, Locke is now only ordered to kill Jul Mdama but extract Halsey alive. After this, Palmer is probably simply ordered by ONI to be nice to her again. But Halseys then sends hidden messages to Chief, tipping him off about the fake, and that she has the original.
The race is now on. Master Chief must find and protect the real Cortana before ONI find her and kill “both” Cortana and then Halsey. At the end of Halo 5, Chief finally arrives in Sanghelios to see Halsey to get the real Cortana back. This is when Halsey says “It took you long enough (to work out the clues and come and get her)!”
The real Cortana will now return in Halo 6 to help Chief fight her new, little Evil ONI sister! 
Alas, the brewing war between ONI and the UNSC has finally begun…
If this is all correct, it’s a brilliant plot, 343! Devious, sneaky, and underhanded, but brilliant!!!