Jorge was the first of the IIs to go over to the Fleet, though it wasn't for a while.
With the intel the Fleet had provided, the Insurrection was mostly quelled and reintegrated into the UNSC, with concessions and new charters on both sides, but it still took years for the fighting to be over. The Arbiter had his own problems to deal with, and he did eventually invite the Fleet to speak to the Covenant's devotees. Like the Bellogeri, there were some who refused to accept the truth, but there were many more who did.
Jorge was the first of the IIs to go over. While there was still fighting taking place, mostly with the Covenant loyalists, he got hit hard by a plasma battery that damn near killed him. The UNSC was able to flash-freeze him and bring him back, of course, but even with cryo and medicine and augmentations, the Spartans were beginning to feel their age. Even Johnson had finally taken a desk job after nearly losing both legs to an Innie bomb.
The UNSC had contingencies, of course. They had already begun training a new generation of Spartans - SPARTAN-IVs - with the few remaining IIIs, and they were put into the field with the teams of IIs to give them experience and examples. And as they grew in skill and experience, the UNSC started pulling the IIs back. They were heroes to the populace, and upon learning of it, ONI had immediately adopted Directive 930 - Spartans never die, they're just Missing In Action - just in case. Still, if something public happened… and the S-IIs weren't exactly young anymore… Well, the S-IIs and IIIs were perfectly content to step back and let the S-IVs take over as the public face of the Spartan Corps.
Jorge was the first to go over, but he was far from the last. He was still sore and limping with the surgeries when he hobbled onto the Storm. John raised an eyebrow at him, and the other S-II waived a hand. "Fuck off," he growled, which made the other grin and step over to slide an arm over his shoulders and take most of his weight.
The rest of his team - James, Keiichi, and Isaac - weren't far behind, and then it was nearly a deluge, one S-II team after another retiring from the UNSC and jumping ship to the Fleet. Some of the S-IIIs came in the later days as well - Jun, Tom, Lucy, Kevin, Hazel, and a dozen or so others – and some IVs behind them.
("Are you going to steal all of the Spartans, Supreme Commander?")
("Acquiring, Admiral Hood, we're not stealing, we're acquiring. And I hadn't planned on it, but now that you mention it…")
(The amused-exasperated expression on the other's face had pulled a short chuckle from the Spartan.)
The Ecumene was eventually renegotiated, rebuilt, this time with the UNSC and Covenant species, and the Bellogeri, Amerontiki, and all the others.
('A Fourth Ecumene. Do you think we'll live to see a Fifth, Commander?')
([Oh Divines I hope not. Let's not try to look that far ahead, shall we?])
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Halsey herself was the last to come over, just in time for John and Cortana to be formally married. They had chosen to adapt the Saavaasi wedding traditions for their own use, with the wholehearted approval of the people themselves. Since the Naga-like people had arisen on such a dangerous planet, they valued the ability to defend themselves, their family, and their clan above all else. As a result, their engagement tradition involved one of the parties forging a sword for the other. If the receiver did not wish to be married to the giver, then they simply kept the sword to be either passed down for the children's use before their own engagement, or they melted it down for use in a sword for the one they did want. But if the sentiment was returned, then they forged another sword to give to the original giver.
("And here I was going to propose with a boring old ring.")
("But this is so much better, isn't it?")
("You know me so well, Cortana.")
With swords exchanged, they spent a year and a day (roughly six hundred Earth days) training together and learning to work with the other, to defend each other. When the engagement period was finished, they entwined their tails (or in this case, stood back to back) and fought against a certain number of relatives of the other's family. (Both of them lacking such members, they fought against some Spartans and other members of the Fleet.) The objective on both sides was to draw first blood; the couple could take a nick from each of the other combatants, while the others could only take one from either of the couple before they had to withdraw. If the others got all their nicks in before the couple could, then they had to train for another year and a day before trying again. But if the couple blooded all the others first, then they were wed in the eyes of the Saavaasi.
("OW! Son of a bitch!")
("James, you okay?!")
("Your wife got me in the balls!")
But John had a hundred thousand years' worth of experience for Cortana to draw on, and the Spartans of the "Parallel" weren't so different from those in the Origin that his knowledge there wasn't worth anything. The AI got nicked three times, and the Spartan once, before they took down all the others.
And they all lived in relative peace - until Cortana started thinking.
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"I've been thinking."
"Don't hurt yourself."
Cortana swatted the Spartan, but there was no real heat to it. Still, he'd turned his head to listen, so she continued, "I've been wondering… what would a child of ours be like?"
That made John frown and actually sit up to look at her. "Define 'be like.'"
"You know what I mean."
"No, I'm not sure that I do. I can't see a child of a Gravemind being anything other than another Gravemind or a monster."
"Not like that. I mean… maybe like how the UNSC makes AIs. Cognitive impression modeling, our patterns combined."
"AIs made from our minds, planted in Flood flesh programed to grow and age naturally? Like a normal human's?"
"If that's what it takes. We have Halsey's genome on file - or even Miranda's - and I still remember yours, so that's also an option."
The Spartan leaned back on one elbow with a soft smile. "You really want a child from the two of us?"
"...Sort of, yeah." She tucked herself up against his side, and he drew her in gladly. "I just… I know nothing can really happen to us. Like you said, 'bold of you to assume the UNSC can get rid of us; we can't even get rid of ourselves.' But, if something does happen… Whenever an AI is sentenced to final dispensation, there's nothing left, no real core thoughts or memories, just scattered data. I…"
"If something happens, you want to leave behind real proof that you were here, that you loved and were loved." He rested his chin on her head. "Something - someone - as proof of existence."
"...Yes. I do."
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It took a bit to work out the specifics, but they did it. And not just them, but others, too. For the first time, the Flood created life, instead of taking it.
The Spartan and AI unexpectedly wound up with fraternal twins, a girl and a boy, and though they had different names when they were young, when they reached adulthood, they named themselves after their mother, in a way.
I am Cortana, of the same steel and temper as Joyeuse and Durandal.