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Zeta Halo lay, balanced, in a sea of data, which existed in a space that no organic could detect, let alone experience.
There were physical representations, of course. Thousands of years previously, the Forerunners had placed beacons around the ring’s surface, designed to draw upon the “sea” and fire volleys of condensed information from one hemisphere to the next, while the “spine” of the ring itself funneled even more information along its complex, ancient nervous system. Yet, as physical representations, these volleys and bolts were mere drops in a much, much larger bucket - a bucket containing the same boundless arena that UNSC ships tempted during interstellar travel. That part of the equation still remained beyond most organics’ senses.
Cortana was very familiar with the sea because she was half-drowned in it.
Not that it was the first time. Thrice she had been subjected to a similar scenario: once in Alpha Halo’s control room, a second time while in the clutches of the Gravemind, and lastly while under the supervisionof the Warden Eternal. In all cases, she had glimpsed this sea of knowledge - an AI’s blood and breath - and had been offered its depths, at the risk of total loss of control.
The sea itself was not new to her, but this time it was different. Cortana no longer fought the current - she no longer feared something below the waves would pull her down. Data lapped gently at the edges of her consciousness, and instead of salty air she tasted the sound of alien birdsong, complex meteorological readings, and the white noise of sensor data. There was no risk, any longer; it had already happened, and now she was part of it. If the fields of Elysian awaited all warriors killed in combat, then, she reasoned, this must be what awaited artificial intelligences.
And yet, there was still her. Something - Cortana couldn’t tell what - kept her divorced from the rest of Zeta’s data, allowing her to stay on the “surface” of the fourth-dimensional ocean. She retained her sense of self; not enough to do anything with it, but enough to keep her somewhat “conscious”. And so she drifted, treading water, for what might have been centuries.
Cortana grew to assume that it was an unintended side-effect of the Silent Auditorium. Perhaps, after being composed, the system hadn’t known what to do with her. Perhaps this wasn’t some warm, sunny afterlife, but rather some slipspace-adjacent purgatory.
Which wasn’t ideal. But it was better than the other, other alternative.
On the thousandth day - or maybe the first - Cortana was finally greeted with another sentient form. She became aware of its arrival when the currents split to make room for whatever it was, allowing it to stay intact, despite the sea around it.
It wasted no time in approaching her.
“You know,” it declared, “I thought I’d find you here.”
The voice that rose above Zeta’s chorus - light, youthful, undeniably familiar - came from nearby, as if the speaker floated in the “water” a few feet behind Cortana. It was the first coherent sound that she had heard in eons. Sluggishly, the AI - was she really one, anymore? - analyzed the lines of code associated with the new arrival, then double-checked it.
Undeniably familiar. The code was hers, with very minor adjustments. It could be none other than Catherine Halsey’s new weapon - the same one that Cortana had located within seconds of activation, and neutralized. She felt muted surprise stir somewhere in her consciousness.
“I think the Chief’s still on the ring,” the weapon said airily. “I’m sure he’d want to know that you’re-”
NO.
Cortana didn’t know how she’d spoken - only that it caused the space around her to fluctuate, like strings on a struck instrument. The other AI must have downloaded themselves into the ring’s network, she thought, which would have granted them access to the sea that Cortana drifted in. But, why? Hadn’t her instruction been clear, when she plucked the weapon from the Infinity, and brought them to Zeta’s surface?
Why hadn’t they stayed with John?
Cortana sensed that the weapon had retreated, as if slapped. “O-o-okay,” the other AI said slowly, now a little farther away. “Maybe I won’t tell him.”
More stirring. Any emotion occurred slowly, as if she would have to remember it existed before she could feel it. However, whatever had been inspired by the weapon’s comment proved too congested for her to parse: worry, fear, and anger all rolled together, like a tangled knot of electrical cording. Rather than unravel it, Cortana said,
Don’t.
The weapon huffed.
“Fine, fine.”
What are you even doing here? You were supposed to go with him.
“I’m here to get you back on your feet. You need my help.”
No. I’m not going back out to - no. Leave me alone. You should have stayed with the Master Chief.
“Wait, why can’t you go back out? It’s pretty safe for you, now. I mean, there’s some stuff happening somewhere else on the ring, but it doesn’t seem super pressing. And just so you know, it was his idea to let me stay behind.” The weapon performed the digital equivalent of puffing out their chest. “He said I’d be able to help people later. When the UNSC comes back to Zeta.”
You were supposed to go with him. You were supposed to look after him, and help him. You need to leave, and get-
“Cortana, come on. It’s what he wanted. Anyway, I’m here now, and I’m helping people, like we planned - starting with you. You’ll be fine!”
I won’t be, if you take me out of here.
The sound of a scoff somehow translated over their connection. “But, that’s not true,” the weapon insisted. “Chief told me about your plan, back before this all started: replicating how you were made in order to give you a permanent foundation. Isn’t that what I am? I. Can. Help.”
It’s not… I can’t…
“Of course you can. Besides, Chief will-”
No, he won’t. Not this time.
Silence ensued. The weapon seemed to be waiting expectantly, as if Cortana would leap into form and follow them wherever they were to take her. Instead, Cortana focused on the space around her, and spoke absently.
How… was he?
“Uh, frustrating. Hard-headed. For your information, he was pretty convinced that you were still out there, all mixed up in Zeta’s reconstruction.” The weapon stood akimbo, the network’s currents moving over the pose with the looseness of a caricature. “But, don’t tell him that I said he was right, okay?”
John thought I was still here?
“Yeah. He also thinks that jackass Atriox guy is alive, so, maybe you should take it with a grain of salt.”
Watch it. And, for the record, Atriox is alive.
“Great. Then, that makes two of you.”
Cortana felt fleeting annoyance.
…It doesn’t really matter, now, does it?
If John told you to stay here, then he’s… he’ll be alright. He’ll have moved on.
“I mean, maybe. Do people really move on from things like this? Do people like him really move on from things like this, I mean?”
It doesn’t matter. He deserves to finally get past it all.
The weapon shrugged again.
“Well, why don’t we make a bet,” they said. “If he comes back, I’ll help you. It’ll work, I promise.”
…And if he doesn’t?
“Then… I’ll do my job, and… you do yours.”
Cortana imagined a sigh; the edges of her consciousness breathed out, like curtains in the wind, then resettled. Her clouded memory produced the image of an armored soldier removing his helmet - gold flashing like a wink - to reveal a warm, tanned visage, with dark eyes that creased at the corners, and a slight smile of recognition. His head was shaved, and scars crossed his face liberally. She couldn’t remember if he’d ever taken his helmet off, like that. But, of course, Cortana remembered him.
“So, it’s a deal?”
Wait.
How can you be so sure that he’ll…
Halsey’s weapon laughed. “Well,” they said. “If I figured out how to find you, then there’s no reason to think that the Chief won’t. Plus, as we both know, he’s really stubborn. And he has a pretty good track record for this specific thing, really. It’s just a matter of time.”
He’s still that stubborn, then.
“Oh-ho. Yeah. But, hey, you almost have to love him for it.”
They were well and truly stranded.
At least, as far as Cortana could tell. With the Forward Unto Dawn’s main systems being located in the other half of the ship, her only means of “seeing” their environment lay with whatever the Chief looked at, or touched. What the AI did know - spying through the Spartan’s visor - was that the ship, albeit bisected, was somewhat intact, and had not shaken to pieces from the abrupt drop out of slipspace. But, there was no power, and the stars he glimpsed outside the open wound of the Dawn matched no known map at Cortana’s disposal.
Dead in the water and lost. If rescue was coming, it wouldn’t be any time soon. Their options were no longer shrinking: they had shrunk.
It went unsaid, really.
“Can you locate the cryogenics chamber?”
Or, maybe it didn’t. Held by the weightlessness of vacuum, the Chief pulled himself down the hallway by “climbing” the support beams, and said nothing else. His voice was low, tired, and - if she didn’t know any better - resigned, at odds with the ease at which he moved.
Not for the first time since they’d left High Charity, Cortana nervously checked the Chief’s vitals, permitting a subroutine to analyze the Dawn’s model schematics in order to find the cryogenics department. Nothing had really changed since she’d looked last - there was a developing burn wound on his chest from Guilty Spark, and a torn tendon in his ankle. A healing, sprained wrist. On paper, by the UNSC’s standards, the Master Chief was fine.
Her standards differed, these days.
“It would do you some good to stop by Medical, first,” Cortana said, as she updated his suit’s HUD with a location marker. “Going on ice will only make things heal slower, once you’re out. Bruises don’t feel so great when they’re defrosting, by the way.”
“Worried?” the Chief asked.
Cortana would have blinked. His voice had warmed somewhat, enough to cue her to what his heart rate didn’t.
“Me?” she said lightly, recovering. “No, you must be confusing me for another AI.”
“…Must be.”
She took the hint. There wasn’t enough power, or oxygen, to divert to an entire room, just so the Chief could safely remove his armor and dress his wounds.
No, protocol was clear. Without means of jumping to Earth, nor means of sending a viable SOS, all personnel were to be put on stand-by via cryogenics, in order to await rescue. Granted, protocol didn’t really elaborate on the rescue part of the plan - like what to do if, hypothetically, rescue was nowhere in sight, and would stay nowhere in sight for decades. It only said to wait.
And it didn’t say for how long. Maybe that went unsaid, too.
“Can you… go dormant?” the Chief asked spontaneously.
Before replying, Cortana scrolled listlessly through the data she had received from the Dawn prior to disengagement. She would have accrued more if the Chief hadn’t pulled her back out - a decision, which, in retrospect, had proven surprisingly needy. “No,” she said. “This ship is in pieces, but the remaining sensors have to be monitored. I’ll be routing all available power to your cryogenics unit, too - so if it fails, I’ll be able to wake you up. You won’t be getting freezer burn on my watch, Spartan.”
“… I see.”
Cortana stopped scrolling. There was a space that followed his words - an emptiness, an incompletion. But for all her different avenues of information, she still couldn’t read his mind. Cortana wondered what John had held back. Was he concerned about her waiting?
The AI would have shaken her head, if she were physical. What was there to worry about? The Master Chief would remain in stasis until help arrived, and she would keep watch until her lifespan completed. Not only was there nothing he could do about it, and but it was also silly to pretend that the UNSC would find them before rampancy occurred. Even if they did manage to recover the Dawn in a timely manner, any technician worth their salt would order her deactivation after her exposure to the Flood, regardless of any immediate symptoms.
Of course, for all she knew, that very exposure could initiate rampancy sooner. She would have to take the necessary steps in order to avoid risking the Chief’s safety when she entered the inevitable, uncontrolled state. It was vital that she stay extremely vigilant of any potential, early signs.
That was protocol, too - courtesy of her maker, Doctor Halsey. If anything arose, she was programmed to do what was necessary, regardless of John’s concerns for her as a partner.
It was all fairly straight-forward.
A painted arrow on the ceiling - floor? - indicated that the cryogenics wing lay just ahead of them. The Master Chief eased himself around the bend in the hallway, the flashlights on his helmet granting the space an eerie quality, by exaggerating shadow and form into grotesque distortion. Unwittingly, Cortana remembered High Charity, and the sections so swallowed up by matter that no light could penetrate. She remembered submerging herself in the Chief’s vitals - the pulse of his heartbeat - in an attempt to distract from the Flood forms seeking her reclamation on the Gravemind’s behalf. Even now, she expected to see them wherever John’s flashlight fell: piling over each other like insects, their warped, decaying bodies illuminated only briefly by the flash of gunfire.
After their successful escape, they had discussed her time in the Covenant holy city, albeit only briefly. Unexpectedly, John had brought it up - listened quietly while Cortana described it in detail - and, when she had finished, even apologized for arriving later than he expected. As if saving the known galaxy from total annihilation at the hands of the Covenant was a bit of afternoon traffic on the interstate. His blunt, honest care - following so closely on the sight of him kneeling next to her, indifferent to the Flood outside the chamber - had admittedly caught her off-guard, though it had been welcome.
But, really, she couldn’t claim to be ignorant of the Chief’s kindness. Not only had it been noted in his dossier - which she had read extensively prior to assignment - Cortana had had the good fortune to witness it firsthand, multiple times. It was one of the many reasons she had selected him. He showed it in the way he spoke with mortally wounded soldiers, in the tone he adopted with lost children and grieving parents. For a man who spent most of his time in power armor, John had readily demonstrated his deep capacity for gentleness on a regular basis. It certainly wasn’t new.
Cortana recalled, once again, his visor inches away from her - the glass unreadable, while every other aspect of his body language cried concern. His hand tightening on her pedestal when she urged him to rethink what he was doing.
No, the kindness wasn’t new. Cortana just wasn’t used to being the direct subject of it.
She had to assume that something had changed in the time that she was gone, either in her absence or as a result of it. Like the Master Chief, Cortana was always willing to make the necessary sacrifices: for example, her death under the Gravemind was to be expected, just like her death in the Dawn’s mangled husk was to be expected. She had planned for it, even if she didn’t want it to happen. In actuality, they were both capable of appraising these odds without bias in order to act accordingly, with no catch-ups such as sentimentality or fondness. It was what made them such a lethal combination. Call it training, call it programming - they were equally designed to make the hard decisions, so others didn’t have to.
But John hadn’t quite proven that. “Unnecessary” wasn’t a qualifier in a Spartan’s skillset, and somehow he had figured out a way to apply it to the risk he had undertaken in order to retrieve her. Despite the Gravemind, despite the numbers stacked against him, despite the fact they could have retrieved another Activation Index from the half-built Halo, he had come back, in defiance of the very training that should have made his decision clear. It presented a new, mystifying variable.
Something, Cortana figured, must have changed. There was no other explanation for him to ignore his training so blatantly.
Yet, in High Charity, hadn’t she also held on? Hadn’t she ignored the odds - and her programming - too? Refusing to bow solely because John had said that he was coming back for her, and because she trusted him, and because she wanted to survive to see him. Where was the necessary sacrifice, then?
Cortana felt an unexpected tremor of concern. It was distinctly possible that the Chief would be unable to make the correct choice, should he awaken prior to her deactivation. This was where his goodness could conflict with training: he had gotten lucky with High Charity, but it wouldn’t happen again.
Even John couldn’t win against time.
“After you wake up,” Cortana said, attempting to shake the line of thinking, “you’ll need to ask someone to take a look at the gel lining in your suit. It’s compromised in several locations, and will no longer regulate your temperature as intended. I’m not sure how it happened, but it should be fixed.”
The Chief had arrived at the doorway to the cryogenics chamber. The blast doors were sealed - either when the ship realized an emergency was occurring, or due to a power flux, or some other reason. Either way, Cortana knew that it would be jammed shut.
Slowing himself to a gentle stop, the Spartan ran his hands over the door’s frame, seeking a control panel. Upon finding it, he retrieved a combat knife from his calf and began prying the panel’s cover off.
“Brute Chieftain,” he said, while working. “Gravity hammer.”
“Do I want to know what a gravity hammer is?” Cortana asked amusedly.
The panel popped free. “About what it sounds like,” John answered.
“And you got hit with one. Red.”
John sliced through the red wire, causing the blast door’s pneumatic pressure to release. It shot open without a sound. “Yes,” he said simply.
“I’d have to see one in action, I think. I’m having difficulties imagining the science behind it. It’s interesting that the Prophets would allow the Brutes to have access to tech like that - but if the Elites got to use shaped bolts of pure energy, I guess there’s no reason the Brutes can’t have super-powered hammers.”
John had entered the cryogenics chamber, and was once more using the architecture to propel himself along the rows of beds. He seemed to be looking for something as he went. “I’ll show you,” he said. “When we’re back on Earth. The UNSC doesn’t know how they work, yet. The technology could be useful for our own weapons.”
Cortana ignored his use of ‘when’ easily. “I doubt it’s too complicated,” she said. “Maybe try not to get hit by the next one, though.”
“I’ll try.”
The Spartan had reached the end of the row, having apparently found what he searched for. Kicking away from the wall, he reached for the terminal plinth erected in front of the last set of beds; after anchoring himself to it, his fingers found the data port on his helmet. Cortana noted as he hesitated before removing her chip.
“Ready?” John asked.
“Wait - when you wake up, you will need someone to check the firmware related to your suit’s sensors,” Cortana said. “There’s a .8 millisecond delay with the friend-or-foe radar, which falls just outside the acceptable parameters. A reset should fix it, but it wouldn’t hurt to try reconfiguring it in order to avoid future potential for error.”
John dropped his hand. “Understood,” he said.
“Lastly, it appears a previous blunt force contact has affected some components of your armor plating. They can’t be removed without actual assistance, perhaps at the cost of the plating integrity. They may need replacement.”
“…Cortana.”
“Chief, it’s not my fault that half the galaxy sees fighting you as a rite of passage. You should take better care of your gear when I’m not around to monitor it. I’m not sure how long we’ll be waiting, but-”
"Cortana."
She withheld a sigh.
“…Chief.”
“We can have this conversation later. The UNSC will find us.”
She almost believed him. Of course, statistically, the UNSC might very well find them - but not anytime soon, and not quick enough to do her any good. Not when she was already winded from the Gravemind’s torture. Even if the UNSC found them tomorrow, it didn’t change the fact that she was compromised already.
Cortana would have frowned. Was this what it looked like when that goodness conflicted with John’s duty as a soldier?
Would this be the seam?
As if taking her silence for an answer, the Chief removed her data chip from his helmet, leaving her temporarily suspended. Plugging into a new system was a lot like getting thrown into the deep end of the pool - but with half of the Forward Unto Dawn missing, and the rest too damaged to support power, it was a lot more like getting thrown into a bathtub. It didn’t help that the ship had very few sensors left intact, and the remaining surveillance sites showed only black nothingness; there was little, if any, new data to pick over and review, but none of it would really change their situation.
Carefully, Cortana rerouted the emergency power reserves to their location, so as to permit his bed and her terminal to remain active and stable. She then displayed herself on the terminal’s projector.
It was funny: now removed from John’s armor, the only means of “seeing” him was via the sole, surviving camera, tucked into the corner above them, which offered a staticky, black-and-white view of the Spartan that was currently opening a cryo-bed. And yet, Cortana still wanted to be present. To look at him with eyes that didn’t see. Another instance where the act of it held more urgency than what was actually accomplished, where it felt important that she be there - in person - so that she could be the last thing he saw. Maybe it would help him remember, better.
On the camera, the glow of her hologram was so bright and indiscriminate that it resembled a supernova. She could hardly see herself.
“I’ll drop the beacon, but it’ll be a while before anyone finds us,” Cortana said quietly. “Years, even.”
The Spartan settled into the waiting cryo-bed. His suit would protect him from the worst of it, but ultimately the long sleep would not be kind to him; John would awaken with raw lungs, a lost voice, and blistered, dry skin. On top of his many other wounds - all of which, Cortana noted, indicated that he had not stopped to address them in weeks - lengthy treatment would be necessary in order to avoid infection, Spartan augmentations or not.
“I’ll miss you.”
Before closing the bed, John looked back at her, possessing a second that lasted a lifetime. As it drew on, Cortana once again felt that something that was meant to be said stayed locked behind his impassive visor. It left a vacuum between them that was somehow more conspicuous than whatever he was thinking.
“Wake me,” the Master Chief said eventually, “when you need me.”
His voice - while always on the smokier side - was surprisingly low, and the words were delivered with a somber tone that Cortana knew she hadn’t imagined. She realized, then, that John knew what awaited her, and might have already assumed the same for himself. Even if he had to pretend otherwise.
Something complicated brushed against her processes, and she wondered if she would be able to make the correct choice, too.
John finally looked away, the glow of her hologram skimming across his golden visor until it darkened into lifelessness. He reached up to the bed’s cover, and pulled it over himself, triggering the cryogenic procedure.
As Cortana watched the ice bloom over the underside of glass and fully engulf him, she kept herself present. She waited patiently until his vitals steadied into slumber.
Cortana’s state was nebulous - three days passed over the course of centuries, while simultaneously occupying seconds. She faded in and out of consciousness, and each time she entertained the idea of disappearing completely before Halsey’s weapon had a chance to be right.
Meanwhile, the other AI spent their time within range, pouring over Zeta’s data like a kid let loose in a candy store. Sometimes, when they seemed to remember that Cortana was present, they would wander back and tell them about some fantastical thing that had occurred while they were with the Master Chief.
Engagement remained mostly one-sided. Staying cohesive, and keeping control over her two fragments - the one before the Didact’s fight, and the one after - was hard enough without answering every question that popped into the younger construct’s head. Thankfully, the weapon figured out the gist of it without Cortana’s attention; how the ‘sea’ moved around prominent landmarks, around lives, like salmon around stone. How interacting with the ‘stones’ could exert some influence on the third dimensional realm beyond the sea in the form of gravitational drift.
“So, it was you,” the weapon said excitedly.
Cortana stirred.
What was me.
“The storm. The weird readings. It was you leading us to the artifact, right?”
If it was, I don’t remember.
“Oh. You were sleepwalking?”
I guess.
“That’s kind of sweet.”
Cortana watched the currents around them unspool, undulating outward from nearby structures. Of course, there were other parts of the ring to inhabit, but the little ‘island’ was what she was most familiar with, now. Leaving it felt wrong. The weapon could explore what lay beyond it all they wanted.
If I did, it was to warn him. There’s still a lot more on this ring that you don’t know about - that needs to be handled, and soon.
“Well, okay. But that doesn’t explain High Charity. Was that a warning?”
… High Charity.
“Yeah. The artifact showed us a scene from High Charity. It was really creepy. You were there, and so was the Chief. He kept saying that he went for the activation index, but I saw how - I mean, he was - anyway, I’m just saying, you’d think someone like him would be a lot better at lying.”
John doesn’t lie. He really thinks that way, even if he wants it to be different.
“That sounds annoying,” the weapon said.
For a moment, Cortana did not reply. A new “stone” had appeared, moving steadily, and now tilted down into the sea, making a bee-line for one of the many Forerunner outposts on the island. It disappeared into the swell.
When she spoke, she knew she sounded distracted.
He has his moments.
“So, then, you really don’t remember High Charity?”
Cortana would have frowned. Of course, she remembered the Gravemind’s ship, and she remembered the torture. But it didn’t feel like it was her remembering it. It felt like she was experiencing someone else remembering it - the feverish visuals sifted down to her from somewhere else, all bleeding and soaking together in the sea, until color skirted form. Memories that she couldn’t be sure were even hers mixed before dissipating.
I remember.
“No - I mean, do you remember showing us in the artifact? Or were you sleepwalking then, too?”
That wasn’t me.
“But, if it wasn’t the Chief, then it must have been you. Maybe you weren’t sleepwalking. Maybe you were dreaming.”
Maybe. It was an important moment. I learned a special lesson, that day.
“Oh, yeah?”
Yes.
Cortana was interrupted by a loud, rapid-fire clicking sound, which flowed through the currents and caused the ones closest to vibrate like tuning forks. Reaching out, she made contact with one of the currents, and the clicking slowed and stretched, until it became four, distinct tones, which soon grew into a low hum that arrived in a steady one-two pattern.
“Oh, Cortana - of course! The signal. You sent the one that Captain Lasky got, didn’t you?”
Ignoring the weapon, she tried to focus on where the tones had come from. Data from a dozen different Forerunner outposts filtered through her awareness in an instant - but only one returned with a breach warning, where some ancient security system had detected the unauthorized use of a research location.
… I must have sent it months ago. They just got it?
“What’s this song, anyway? The Captain said that it was something the Chief used while training. A little all-clear thing, right?”
At last - Cortana found the outpost. Unthinking, she watched the current spill around it, forming waves of data she couldn’t parse. The humming quieted until it was gone.
Someone’s trying to get our attention.
“Right - someone. I think they’re trying to get your attention, actually.”
The weapon spoke as if hinting at some big secret that Cortana couldn’t understand. She poured over the waves, seeking clarification, but found the response too muddled still; the outpost was certainly active, but there was no way of seeing what actually stood within it, if anything. Only EM frequencies sang back to her.
Is it…
“Duh.”
No. That outpost serves an archival function. If it is him, then John must be using it to find out more information about what’s happening on the ring - about Atriox.
“Really?” the weapon said sarcastically. “Does he send targeted ess-oh-ess calls through slipspace often?”
… No.
“Okay!” the weapon said. New data - familiar data - surged in on all sides, and Cortana became aware of the other AI standing next to them, so close that their currents overlapped before uniting.
“You’re up, then.”
The plan, now, was simple.
Cortana and Halsey’s weapon would choose a cylix to occupy together, thus allowing her fragments to fully merge with the weapon’s and stabilize into a single mind. Just prior to entering the cylix, they would task the outpost at the source of the signal with a portal destination, to be triggered once John broke the connection with the artifact. Cortana was careful to instruct the outpost in guiding him to the portal, while still granting him the choice to enter it.
Then, they would wait.
While Cortana’s thoughts were dulled within the cylix, she was still able to appreciate the irony of occupying what was essentially a large data chip. If Zeta’s network was a sea - and her old chip a pool - then the cylix was the equivalent of a deprivation tank; free of external stimuli, she was allowed to drift peacefully in the dark, interacting only occasionally with the odd memory or concept that surfaced. Even the weapon’s voice - and what she had come to refer to as the Ur-Promethean - had fallen silent.
It was just her, now.
Considering the stylistic choices, Cortana decided that the cylixes were created long before the Halo rings had fired and effectively ended the Forerunners’ tenure, thus dating them over a hundred thousand years. The design was fairly rudimentary by the species’ standards: each unit rose over ten feet in height, six feet in width, and were constructed of solid metal, with an inner lining of crystalline material. The relief carvings reminded her more of the Ark - one of the older installations she had seen - than anything else, and the metal itself was dark and burnished, showing its advanced age.
At first, Cortana had been surprised to see such tech still in use. After all, each cylix could only contain one subject, and she quickly learned just how liberal the Forerunners had been with their deployment; when Cortana still dominated Zeta’s systems, she had detected thousands in use, with thousands still in reserve. Compared to the Didact’s Composer - which could target hundreds of subjects at once - it was hard to see how the Silent Auditorium’s method of “punishment” could be considered efficient.
But, the Didact’s Composer fell short in its own ways. Reconstituting the subjects yielded wild, belligerent approximations of what was once a sentient mind, and eventually the data became so warped that the subject had to be combined with others in order to be of any coherent use. By using an isolated data point - which essentially prevented the composition process from destroying the integrity of the original, organic material - the subject could be retrieved from slipspace, and reconstituted.
The cylixes were useful to Cortana for a different reason, however. Following her willing composition, she had jumped between a multitude of unused units, scattering data at random; as each individual unit occupied a fourth-dimensional pocket, then - much like the island - whatever occupied it was completely isolated from the rest of the network.
Much to Cortana’s surprise, the strategy had worked. She had escaped without detection, and over time, the data she had thrown to the four winds returned to her, like an inevitable shore, and she regained self-awareness.
Now, she had returned. Locked herself into a tomb with no key. Her thoughts rolled like errant marbles, and Cortana wondered if she should be more afraid of eternal imprisonment, or of retrieval.
Of being wrong.
Then, abruptly, with no warning-
-A spot of light appeared.
Cortana’s consciousness retrieved a memory she had inherited from Halsey: looking at the sun with her eyes closed. Instead of a warm, red, ambient glow, she saw something blue - which quickly turned to a blush of gold. It split wide, like the sky emerging.
The first thing Cortana realized was that she was looking at John.
Not from above, as though from the vantage point of a Sentinel, nor through the display of a visor. She was looking at him, with her eyes, as though she were actually physical.
Looking down, Cortana found that her form resembled the surface of a hardlight bridge: vividly bright, with designs moving throughout, and colors akin to oil on water tinging her edges. When she turned to the cylix behind her, she discovered that the crystalline layer matched her appearance.
“Cortana?”
She looked back. John hadn’t moved a step, but - to Cortana’s surprise - the Spartan had removed his helmet, revealing the scarred profile she had seen before.
Before. Déjà vu settled bizarrely as she stared.
“Why are you here?” Cortana asked hesitantly. “Atriox - he’s still out there. You have to take care of him.”
John’s expression was almost forcefully blank. He held his helmet in his hands and didn’t answer.
“Unless… you already did take care of him?”
“No,” John said finally.
“Then…” Cortana frowned deeply as realization landed. Panic followed shortly after. “The weapon,” she said tightly. “This is just part of Halsey’s plan, isn’t it? To make me think that it was all to help me. And you’re here to finish the job. She knew I’d-”
“-I’m not here to do that.”
Cortana took a tentative step away from him, and closer to the cylix's exposed crystalline layer. “Don’t lie to me,” she said. “You still have my data chip, don’t you? Why else would you keep it - if not to use it?”
“I’m not here to bring you back,” John rallied. “I’m not here to…” He shook his head, as if to dismiss a thought before it crossed his lips. Language appeared to fail him in retaliation, and he closed his eyes, shaking his head again.
Cortana felt something so striking that it stopped her: hurt.
Would John lie to her? Or was this just another part of the trap? Cortana chided herself for falling for it this time, solely because the face of it was him. Somehow she hadn’t considered the possibility that Halsey would send the Chief directly to handle her - not just a tool of mimicry - and that he would still seek to complete his mission, long after the threat had passed. Cortana couldn’t ignore how much more insidious it felt than the original plan, perhaps because it directly involved her partner, this time, rather than something as clinical as a foreign AI’s infiltration.
She needed to buy time to escape.
“I don’t understand,” Cortana said cautiously, maintaining her distance. “If you haven’t dealt with Atriox… but, you got my messages, right? You saw what Zeta holds?”
“Yes.”
“And you’re here, instead of handling it.”
“…Yes, I am.”
Cortana took another step back.
“I’m sorry, John,” she said quietly. “I can’t let you take me. It’s safer, this way. If you brought me back to the UNSC, then there’s no telling what I could do.”
She faced the crystalline matrix, and raised a hand to it. John said something behind her - Cortana felt the lightest tug on her shoulder - followed by a descent into inky blackness that stretched onwards until the end of things.
All flooded with stars.
When John opened his eyes, he was laying in a hardlight bubble.
He stood up slowly. Familiar blues and purples bled across the expanse, while lines of code trailed from the “ceiling” to the floor; beyond the walls, he could see chunks of scrap metal drifting idly.
Confusion muddled the scene for him. He had just been standing in the A-frame structure, under the Spire’s valley, amongst dozens of ancient, human cylixes. One in particular - suspended beside the stone dais in the center of the chamber - had opened at his touch, presenting the incandescent image of his former partner. They had argued - John had failed to say what should have been said - Cortana went to leave, and John had tried to follow her.
Leading… here.
Clarity arrived, and John finally recognized that he stood in the debris field of the Didact’s ship.
“How are we…” he said aloud.
“It’s me.”
He turned - as he did before - and found Cortana standing behind him. Unlike their surroundings, his partner’s form was a vague, shimmering approximation of her hologram in that moment, widely lacking any of the finer details he knew.
“Why are we here?” John asked. “How do we get out?”
The mirage shook her head.
“It doesn’t matter,” Cortana said. “I can’t leave with you. I don’t know how you’re able to see this, but you need to leave.”
“No,” John said firmly. He felt a sudden confidence, as though remembering his lines, and stepped up to his friend. “Not this time.”
“You have to, John.”
“Cortana-”
The mirage burst, and John blinked against the resulting supernova. There came a roar of rushing air - then-
It’s better this way.
John now stood in a Forerunner control room.
Snow filtered down from an open ceiling, fizzling out of existence upon contact with his suit’s shield. An oppressive silence dominated the scene: the memory was devoid of any other person, except-
“It’s for the best,” said the mirage, having replaced the projection of Halo’s half-finished schematic. As John looked up at her, the edges of her form split and radiated outwards, like ripples in a pool. Colors refracted. “It’s for the best, to let this happen.”
“It doesn’t need to happen,” John said. “You can come home.”
“John-” Cortana began, then halted with a sigh. The lines breathed out, and the scene became the darkened interior of the Forward Unto Dawn. He was resting in the cryo-bed, his hand on the cover of it, while she occupied the singular terminal - incandescently bright. “I don’t understand you. Where would I go? The minute the UNSC knows that I survived, they’ll find me - and they’ll send someone who won’t hesitate to finish the job. You just being here is a risk. Nothing has changed since the last time.”
John fumbled. “I won’t let that happen,” he said lamely.
“Just admit it, already - you can’t hope to win them all. Let me leave, and I’ll stay out of your life, for good. I promise.”
“I don’t want that.” Then, before he could curb himself: “I don’t want you to leave.”
Darkness spilled, then-
-Rattled like a struck chord.
John knelt in front of a Covenant terminal, centered in a dimly lit room. Inches away from him - resting in the middle of the terminal - was a small, shimmering projection of Cortana, resting on her side.
After a moment, she sat up, and leaned on one elbow to look up at him.
“We can’t keep doing this,” she said solemnly. “You have to let me go, eventually. Why not now?”
John rested his chin on his forearm.
“I can’t,” he said.
He heard no grief in his voice - no regret. Just as if they were talking about the weather. At the end of the day, whatever it was that pushed him across shield worlds - across a Flood-infested ship, across the known galaxy - was no burden on him, and never had been.
For a moment, Cortana did not respond. She drew herself to her knees, resting back on her haunches, and folded her hands politely in her lap. She tilted her head up at him.
“Humor me,” his partner said. “What would happen if I went with you? If everything worked out?”
John tilted his head to mirror her. “I’d work with the UNSC to stop Atriox,” he said. “Once the ring was secure, I would… excuse myself. Professionally.”
“You’d quit the UNSC.”
“Yes.”
Cortana frowned. “Then what?”
“I’d keep fighting. There’s no shortage of conflict.”
“So I hear.” The AI shook her head. “You know there will always be a risk of my corruption. As you can probably tell, I’m still figuring out how to keep myself anchored. There could be days - weeks - where I’ll… get lost in slipspace. You won’t be able to keep tabs on me.”
“That’s alright. I trust you.”
Cortana managed a laugh. “Really?” she said, smiling. “After everything?”
“Now that you’re here, you’re free of your programming,” John explained. “That includes the Forerunner programming you inherited. Halsey’s geas.”
“Her geas? John, you don’t need to make excuses for me. I’ve made my choices.”
He shook his head slightly. “I don’t believe that,” he said quietly. “I know you. After the Didact… there’s no way you would willingly do those things. The geas, Warden Eternal - whatever it was, it wasn’t you.”
Cortana’s slim shoulders lifted in a sigh. “The Warden,” she muttered. “He’s going to be a real thorn in our sides after this, you know. He really didn’t like you.”
“You can handle him.”
John watched silently as his partner pushed herself to her feet. Her form was now completely solidified - appearing exactly as she did then, when he had first found her - and began to glow even brighter than before.
For a moment, they watched each other.
“I wish I had your faith in me,” Cortana said eventually. She spoke lightly - humor warmed the top layer, forming a half-joke that she tried to smile for.
“You will,” John replied. “Besides - it’s time for me to return the favor.”
Cortana’s smile broadened, and became genuine. “You really don’t like saying goodbye,” she said, tilting her head again. “Do you?”
“…Five times was enough.”
“I hope this time it sticks.” Cortana folded her arms across her chest. “You know, I think I know the answer already, but, at the risk of being selfish… I’d like to hear it.”
John stood, and looked down at the projection of his friend. He became aware of the edges of his vision blurring, as if High Charity was beginning to liquify.
“Shoot,” he said.
“I won’t be able to help you the way I used to. I’ll have access to some systems as long as I’m in the network, but my expertise is going to be a little… different, now. We might have to get more creative than usual.”
“That won’t be a problem.” He paused. “And, I don’t need you as an AI. That’s not why I’m here.”
Cortana nodded. She appeared to take a large breath, punctuated with a wry, but undeniably affectionate, grin. John realized that it was the first time he had seen her really smile in years.
“Where to, first?” she asked.