User:Dab1001/RefStressTest: Difference between revisions

In 2507, while still a doctoral candidate, Halsey met Doctor [[Elias Carver]] at an academic social mixer and couldn't resist correcting his obsolete algorithm implementation when she heard him describing the matrix mechanics of the socio-economic and politico-economic vectors of human expansion.<ref name="HJ12410">''[[Dr. Halsey's personal journal]]'', ''December 4, 2510''</ref> She outlined a corrective matrix calculation to him which revised his dimensional parameters so that the sixteen dimensions were used rather than seven. Doctor Carver did not appreciate being challenged by someone he saw as a young upstart, but her words seemingly caused [[Captain]] [[Michael Stanforth]] of the [[United Nations Space Command]]'s [[Office of Naval Intelligence]] to take note of her. Three weeks later, a [[Wikipedia:Grant (money)|grant]] she had proposed for using [[artificial intelligence]]s to control N-dimensional matrices was green-lit by the UNSC, with its funding contingent on the successful testing of a model of its choosing. Naturally, it was Carver's model which she was directed to test. Halsey knew his flawed model would produce flawed results, so she ran her sixteen dimensional variant as a [[Wikipedia:Controlling for a variable|control]] in addition to his seven-dimensional version. Carver's model predicted a breakdown of social order in the [[Outer Colonies]] within twenty years unless strict governmental control was established, reinforced by an immediate and permanent military presence. Catherine ran more then fourteen hundred simulations during this time, varying every parameter, and even in the best-case scenario it was clear to her that the Outer Colonies at large would [[Insurrection|rebel]] against the [[Unified Earth Government]] ''soon''. She determined that at a minimum, the resulting conflict would lead to thirty years of war and the deaths of five billion people. The maximum effect was unbounded and could involve interminable war and a new [[Wikipedia:Dark Ages (historiography)|dark age]] for [[humanity]]. Halsey took her findings to Stanforth only to learn that ONI had already reached the same conclusion. The agency had been keeping an eye on her for years and it had been decided that in order to recruit her, she would need to convince herself that working with the agency was necessary to save the human race.<ref name="HJ12410"/> [[Ysionris Jeromi]], who considered Halsey his star pupil at the time, discouraged her from working with ONI.<ref name="HTFOR6">''[[Halo: The Fall of Reach]]'', ''Chapter 6''</ref> Halsey, however, had no problem admitting that ONI's tactic had worked on her.<ref name="HJ12410"/> She allowed herself to be recruited in [[2508]] and in early [[2510]] she was brought to the [[Inner Colony]] of [[Reach]] and contracted to work as a [[civilian]] consultant on a number of classified projects.<ref name="WaypointCatherineHalsey"/><ref name="HJ8810">''[[Dr. Halsey's personal journal]]'', ''August 8, 2510''</ref><ref name="HM60">''[[Halo Mythos]]'', ''page 60''</ref>

Halsey was awakened from [[cryostasis]] alongside Keyes shortly after 0430 hours on [[2517#August|August 17]] while the ''[[Han]]'' was still in slipspace but set to emerge soon in the [[Eridanus system]].<ref name="HTFOR1"/> Giving not so much as an acknowledgement that they were both naked, Halsey simply climbed out of her tube and told the lieutenant to get cleaned up and dressed as she headed for the showers herself, making it clear to Keyes that she was in charge. Halsey was already strapped into the navigator's couch and on the bridge and tapping in commands across four keypads when he joined her soon thereafter. The doctor welcomed him and asked that he be seated at the communication station to monitor channels when they reentered normal space. She then had [[Toran]] provide her with [[astronavigation]] maps of the system and asked if any planets between their current position and [[Eridanus II]] could be used to pick up a [[Wikipedia:Gravity assist|gravitational boost]] to let them arrive sooner. Additionally, in rapid succession she had the A.I. begin to play [[Rachmaninov's Piano Concerto Number Three]], begin a preburn warmup cycle for their [[fusion engine]]s, and halt the rotation of the shuttle's central carousel section to conserve power. Toran obliged with each request and informed her they they would exiting slipspace in about five minutes, give or take three minutes. From the way Keyes was glancing at her, Halsey could tell he was impressed at her ability to put Toran through his paces so rigorously, so she asked if he had a question for her. In response he composed himself before inquiring as to the exactly what they were doing. Halsey told him that they were on a reconnaissance mission of sorts, as they were heading to Eridanus II in order to observe [[John-117|a child]] whom she hoped would only be the first of many. She suggested the junior lieutenant should just think of it as a UNSC-funded psychological study and then sternly told him that was exactly what he was to say it was to anyone who asked. The ''Han'' soon decelerated as it dropped out of slipspace near a gas giant and then began a hard burn, accelerating for sixty-seven seconds before arcing away from the planet. As soon as the boost was complete Toran informed the two humans that their [[Wikipedia:Estimated time of arrival|ETA]] was forty-three minutes and three seconds. At this, Halsey unlocked her harness and floated free. Just before they had dropped into normal space, Keyes had started to ask her if she knew how dangerous the Eridanus system was then and now she finally answered him in the affirmative. After stretching and strapping herself back into her couch, she reminded her escort that he was supposed to be monitoring their comms for that very reason. Catherine spent the next thirty minutes with her back to Keyes while she read over reports on her navigation screens. The Keyes eventually spoke up to candidly ask why he was there, and Halsey told him the truth about why she had selected him for the job. She also assured him that though he may have rather been on the {{UNSCShip|Magellan}} then, which now-rescinded orders had previously had him rotating to, the child they were traveling to observe could make all the difference for the ongoing struggle against the [[Insurrection]]. Once Toran announced they were approaching Eridanus II Halsey had him plot an atmospheric vector for the [[Luxor]] [[Luxor Spaceport|spaceport]] and ordered Keyes to make ready to land.<ref name="HTFOR1"/>

On [[2521#October|October 15, 2521]], while enjoying a slice of custard pie from [[Havadi Goodwan|Havadi]]'s, Halsey took the time to muse somewhat in her journal on the vulnerabilities created by the standardization of operating systems, highlighting the recent disabling of [[UNSC Persephone|a patrolling destroyer]] by a [[terrorist]] who hacked its code.<ref name="HJN1724">''[[Dr. Halsey's personal journal]]'', ''October 15, 2521''</ref> Given that the [[UNSC]], conversely, had not had much success penetrating the homegrown collections of software employed in the [[Outer Colonies]], she concluded that the time had come to think outside the box as far as programming practices were concerned. She had spared no resource in the development of routines that allowed the newly-operational third-generation A.I.s to penetrate any system software. Additionally, they had already learned to mutate and defend established UNSC operating systems from attack, a side effect of the routines which Halsey found serendipitous. Before she concluded writing that day, she took note of the frustration she felt at the way the acronyms for [[Illegal Entry Protocols|illegal entry protocols]] and [[Counter-Illegal Entry Protocols|counter-illegal entry protocols]] had been commonly misspelled and then vocalized based on those misspellings.<ref name="HJN1724"/> On [[2522#June|June 5, 2522]] Halsey was finally offered the position of chief scientist within ONI, after years of only officially serving in an advisory role involving a series of undocumented but well-paid contracts.<ref name="HJN1724"/><ref name="JS6526">[[Jessica Shea]] on Twitter 06/05/2522 [https://twitter.com/bsangel/status/606903711663681536]</ref> Since she had always lacked the time or interest to spend the money earned, these contracts had always benefited her little. Halsey accepted the offer, but was uncertain why it had been presented to her then. In her journal she theorized that the promotion might have something do to with the curiosity of her colleagues and the wider scientific community or might simply reflect suspisions that her temporary unofficial advisory role was in reality none of those things.<ref name="HJN1724"/> Once around this time, when [[Soren-066]] was nearly eleven years old, she approached him as he ran through an exercise with the other children.<ref name="HEP2"/> Soren had been hesitating, unsure of which team to join, so she asked if everything was alright. The boy replied in the affirmative, but slipped up and called her "Sir" before blushing and correcting his mistake. Halsey just smiled and told him he shouldn't get distracted by irrelevant data, then pointed past him as both teams ran for the skirmish ground and added that above all he shouldn't let himself get left behind.<ref name="HEP2"/>  

On [[2524#January|January 18, 2524]] [[Wikipedia:Canada–France–Hawaii Telescope|CFHT]]-[[Mars]] captured a ten minute [[Wikipedia:Exposure (photography)|exposure]] image of an [[High Charity|anomalous object]] within the star cluster [[Wikipedia:NGC 2244|NGC 2244]] and nearing human space.<ref name="HJextras"/><ref name="H11824">[[343 Industries|Halo]] on Twitter 01/18/2524 [https://twitter.com/Halo/status/424662516803710976]</ref> [[J.C.|An acquaintance]] of Halsey's later sent her the image for evaluation along with a note describing the unidentified object as having guided movement and not belonging to the UNSC.<ref name="HJextras"/><ref name="H11824"/> They also gave her a way to reach them on [[ChatterNet]], should she wish to weigh in on this mystery.<ref name="HJextras"/> [[2524#August|August 22, 2524]] left Halsey furious after she learned that her candidates had been rerouted during a training exercise to a [[UNSC Special Forces|Special Forces]] camp on the other side of [[Reach]].<ref name="HJN1724"/> Mendez had told her that "interested parties" within [[ONI]] wished to observe the teens in action firsthand, which made her immediately wonder about someone trying to usurp her project or cut its budget. She took her grievances to Admiral Stanforth, who claimed to know nothing about what had happened and told her to stop being paranoid. Convinced he was not being truthful and that something was going on without her knowledge, she requested that the production of the next-generation A.I. matrix strata be expedited so her new intrusion and counter-intrusion software could be developed to aid the Spartans and protect herself.<ref name="HJN1724"/> On [[2524#November|November 17]] of that same year, Catherine made an entry in her journal following a conference she had attended at the [[University of Calippus]].<ref name="HJN1724"/> While at the conference, she had reunited with [[Jacob Keyes]] and had [[Reproduction|sex]] with him.<ref name="WaypointCatherineHalsey"/><ref name="HJN1724"/><ref name="HG6">''[[Halo: Glasslands]]'', ''Chapter 6''</ref> She was unsure whether her decision to do so had been a result of the dizzying pressure she was under, a response to a chance encounter with a kindred spirit in a strange place, or something else, but she was glad it had been him she'd run into.<ref name="HJN1724"/> The romantic liaison with Keyes left her pregnant with [[Miranda Keyes|a daughter]].<ref name="WaypointCatherineHalsey"/>

On March 9, the day before [[Project ASTER|Project: ASTER]] was to be initiated, Halsey and the seventy-five teens could be found aboard [[Medical Facility Endurance]] in orbit over Reach.<ref name="HTFOR6">''[[Halo: The Fall of Reach]]'', ''Chapter 6''</ref> At 1130 hours the doctor was pacing in the observation room while she waited for for Déjà to decrypt [[UNSC Priority Transmission 09872H-98|a transmission]] from Vice Admiral [[Ysionris Jeromi]]. Catherine had previously proposed a hypothetical series of experiments involving [[Wikipedia:Bonobo|bonobo]]s to he and his team in order to obfuscate her true intentions for the protocols. To her dismay, the latest from Jeromi informed her that further analysis had failed to yield viable alternatives that might mitigate any of the risks inherent to her "hypothetical" experimentation. As soon as she was finished with the file he'd sent Halsey erased all traces of it and even sent Déjà to track its pathways all the way back to the {{UNSCShip|Hopeful}} to destroy his related notes and files. Given the news, Halsey seriously considered delaying the procedures and only put such thoughts aside due to Déjà pointing out that ONI would only find someone else to move the project forward if she started dragging her feet. Chief Mendez met the doctor in the hall outside the observation room and at her insistence followed her up the stairs to the hospital's pre-op wing. Upon seeing John in Room 117 she forced a smile and asked how he was feeling. John, thinking of the procedures as just another exercise, asked her if she could just this once tell him how to win. To that, she could only lean in close and tell him he needed to survive.<ref name="HTFOR6"/> Later that day Halsey divided the various augmentations into two groups according to their risks of failure or long-term side effects not adequately studied.<ref name="HJ3925">''[[Dr. Halsey's personal journal]]'', ''March 9, 2525''</ref> Those that she considered to have unacceptable fail rates were to be tabled for then in order that further research could be done. Already she had begun to quietly arrange [[Operation: TENDRIL|long-term studies]] on the gradual application of cyclo-synthetic neural transmission gene sequences during subjects' early lives and noted in her journal that research on the injection of [[Wikipedia:Virus|viral]] [[Wikipedia:Neutrophil|microphage]]s at neuron surfaces was pending. Halsey closed that day's journal wishing there was a god to pray to.<ref name="HJ3925"/> As she was being readied for the procedures within Lab 7, Halsey visited the girl [[Yasmine Zaman|Yasmine]] and assisted a nurse in strapping her down.<ref name="ILBPM">''[[i love bees]]'', [[Princess Monologue|princess monologue]]</ref><ref name="ILB12">''[[i love bees]]'', ''[[Axon Clips Chapter 12|Chapter 12]]''</ref> She attempted to reassure the girl that she would barely feel anything apart from slight pain that accompanies injections.<ref name="ILBPM"/><ref name="ILB12"/><ref group="note">In the [[Axon Clips Chapter 11|eleventh chapter]] of ''[[i love bees]]'' the A.I. [[Durga]] recites the date [[2537#September|September 16, 2537]] immediately after mentioning Yasmine's involuntary recruitment for the Spartan-II program. Following this recitation Durga mentions Yasmine's post-procedural designation as a medical washout. It may be likely that an error was introduced by seemingly having records which show her as having been abducted for the Spartan-II program years after Project: ASTER had been initiated. Whether the given date actually refers to her original childhood conscription, however, is not completely clear. She is also stated to have died prior to [[2546#January|January 2546]]. The possibility exists that each given date is in error due to having twenty years mistakenly added to the dates [[2517#September|September 17, 2517]] and [[2526#January|January 2526]].</ref> While visiting [[Serin-019]] before the procedures commenced the girl asked her how different she would feel when she woke up.<ref name="HG15"/> Halsey was honest with her and let her know just how painful and persistent the side effects of the surgical enhancements would be if she survived—possibly lasting months or even years.<ref name="HG15"/>

On [[2525#September|September 11]] Halsey had just returned to Reach.<ref name="HTFOR8">''[[Halo: The Fall of Reach]]'', ''Chapter 8''</ref> Chief Mendez was surprised to find her reclining in his chair when he opened the door to his office at 0930 hours that day, as he had been under the impression she would be gone for yet another week. She told him their situation had changed and asked to know where the Spartans were, since she had failed to locate them in their barracks or on any of the ranges. The Chief told her they'd been forced to find them other facilities recently and offered to show her what he meant. He then escorted her to his personal [[M12 Warthog]] and drove them both off of [[Reach FLEETCOM Military Complex|the base]] and onto winding mountain roads leading to a series of [[titanium]] mines. They passed a manned guardhouse before descending steeply underground through a tunnel which wound downward in a spiral. Mendez revealed that dozens of old [[MJOLNIR Powered Assault Armor#Mark I exoskeleton|Mark I]] exoskeletons had been stored down there and were now being used by the Spartans' trainers, three of whom had been accidentally killed on the first day back from [[Lambda Serpentis system|Lambda Serpentis]]. The vehicle came to a stop within a large cavern, Mendez helping her out and leading her to a small prefabricated one-room building. At the push of a button by Mendez the room climbed a track along the wall until they were twenty meters off the floor. When floodlights snapped on a game of [[Capture the Flag]] was illuminated in a large section of the cavern; trainers in armor defending against Spartans. Halsey could not see any of her Spartans at first, but she soon identified a glimpse of motion as Kelly. The trainers were armed with 30mm miniguns loaded with [[stun round]]s, but when one almost landed shots on John at point-plank range the doctor briefly panicked, for even stun rounds could kill at that distance.[[File:HTFOR Laden.PNG|left|thumb|350px|The five Spartans who infiltrated [[Eridanus Secundus]] to capture Colonel Watts did so by stowing away aboard the {{Class|Parabola|freighter}} ''[[Laden]]''.<ref name="HTFOR9"/>]] Once the flag had been stolen without any sign of the Spartans remaining Halsey asked to see what she'd just witnessed again, sure that it had been recorded. Unfortunately, the teens had already found the cameras and disabled them. The Spartans' newfound impressive abilities made Catherine conclude there must be unexplained synergistic effects brought on by the combined modifications. Once she made sure to inquire about any physiological or mental instabilities, she then asked Mendez whether he thought they were ready to kill others in real combat. He believed they were, so she let him know [[First Battle of Harvest|something]] unexpected had happened and that [[UNSC High Command|the Admiralty]] wanted them deployed as a first test. Mendez rightly guessed that the rumors he'd heard about heavy action at Harvest had something to do with this, so it was left to Halsey to inform him that the colony there had been wiped out. She proceeded to bring the observation room back to the floor and told him she wanted the Spartans ready to muster at 0400 hours the next day for a briefing aboard the {{UNSCShip|Pioneer}}, a {{Class|Halberd|destroyer}} which would take them on [[Operation: TALON|a mission]] ONI had been saving for the right crew at the right time. Tomorrow, she said, they would see if all the pain they'd put the Spartans through had been worth it.<ref name="HTFOR8"/> At 0605 hours the next day both Halsey and Mendez met the Spartans in the ''Pioneer'''s briefing room while ''en route'' to the [[Eridanus system]].<ref name="HTFOR9">''[[Halo: The Fall of Reach]]'', ''Chapter 9''</ref> The doctor walked to a the podium and greeted them with good news: Command had decided to finally put their abilities to the test. The doctor explained that intelligence suggested an [[Eridanus Secundus|insurgent base]] had been established in the [[Eridanus system]]'s [[Asteroid|asteroid belt]] by rebel elements who had escaped [[Operation: TREBUCHET]] years before. She further introduced them to the [[United Rebel Front|URF]] leader [[Robert Watts]] and announced that they were to infiltrate the base to capture him alive to be returned to UNSC-controlled space. Halsey then stepped aside so Chief Mendez could go over the details of [[Operation: TALON|the operation]]. When finished, he and Halsey left the room.<ref name="HTFOR9"/>

It was at 1750 hours on [[2525#November|November 27]] that the ''Commonwealth'' finally emerged in real space in the [[Chi Ceti system]].<ref name="HTFOR12"/> Halsey then immediately summoned John to the bridge, where she waited with the ship's Captain [[Wallace]]. The doctor called his attention to a screen displaying deconvoluted radar signals, including one which was repeatedly appearing and might represent another ship eighty million kilometers away. Though Wallace didn't see the need Halsey urged that they go to battle stations and let he and John know that at Harvest the aliens had been observed making an intrasystem slipspace jump, something beyond the capibility of human technology. This new information was enough to change the captain's mind and before long the ship had changed its heading and its bulkheads had been sealed. The doctor informed John that they'd be taking one of the ''Commonwealth'''s dropships to the surface of [[Chi Ceti IV]] and instructed him to get the others ready to depart, seeing as it was vital the Spartans reached Project: MJOLNIR before the [[Covenant]] did. Almost immediately after he'd relayed orders to muster them [[Unrelenting|an alien ship]] [[RCS-class armored cruiser|a third]] the size of the ''Commonwealth'' suddenly appeared three thousand kilometers off its prow. Both vessels quickly engaged one another and Halsey was surprised to see that even a Covenant ship of such small size was equipped with [[energy shielding]]. Even a direct hit from the frigate's [[Magnetic Accelerator Cannon|magnetic accelerator cannon]] only served to disable its shields rather than destroy the ship. Captain Wallace gave orders to ready another round at that, but Halsey argued against this, instead imploring him to initiate evasive maneuvers. Having the doctor second-guess his command led the captain to threaten her with being ''gagged''. Yet soon enough they were been struck amidships by the enemy's weapons and multiple decks had melted in Section One. When fires were reported throughout various sections Catherine suggested the crew don [[respirator pack]]s so the atmosphere could be vented on all decks outside the [[bridge]] and this time, Captain Wallace assented to her reccomendation. When he demanded to know what they'd been hit with she explained that the aliens could evidently [[Plasma torpedo|guide]] the trajectory of [[Plasma weaponry|plasma]] through space. Their MAC system having been destroyed, Halsey next floated the idea of attacking with [[Nuclear weapon|nuclear missile]]s but was once more rebuffed by Wallace since the enemy was far too close to them to make their use safe. Both she and John then concluded that using [[GA-TL1 Longsword]]s to distract the aliens could afford them the safe distance they would need to use nuclear weaponry. To their dismay the smaller ship still remained intact, although obviously crippled, after being hit with the blast of a [[Shiva-class nuclear missile|Shiva-class warhead]]. For her part Halsey could at least appreciate that even if they couldn't destroy the enemy's ships they could evidently at least slow them. With the Covenant craft moving off Wallace ordered the ''Commonwealth'' to execute a [[Wikipedia:Planetary flyby|flyby orbit]] so that Halsey and the teenagers could depart for the [[Damascus Materials Testing Facility]] in [[Vhalkem]] as they passed by it. He told the doctor he would attempt to lead the Covenant ship away if it came back but that they should plan to reconvene in orbit no later than 1900 hours. She immediately turned back to John and told him to they needed to hurry, as there was much she had to show the Spartans.<ref name="HTFOR12"/>

{{Expand-Section}}

The next day Halsey joined Johnson and both admirals aboard the {{class|Point Blank|stealth cruiser}} {{UNSCShip|Vanishing Point}} in deep space within the [[Polona sector]].<ref name="HSS5">''[[Halo: Silent Storm]]'', ''Chapter 5''</ref> At 0558 hours she led [[John-117]] into the ship's tactical planning center for a meeting with the aforementioned men, Captain [[Halima Ascot]], and [[Colonel]] [[Marmon Crowther]], commander of the [[21st Space Assault Battalion]] of [[ODST|orbital drop shock trooper]]s. Halsey took the first open chair around the TPC's conference table and before long was being introduced by Cole as leading their effort to analyze and reverse-engineer alien tech. The mission those present had gathered to discuss, [[Operation: SILENT STORM]], was being conceived of as a desperate mission with the stated aim of boarding as many Covenant capital ships as possible in order to detonate small-yield tactical [[nuclear weapon]]s within their hulls. When Colonel Crowther balked at these aims, Halsey suggested that John be put in command of his troopers. She had previously broached this suggestion with Cole, who rebuffed it for a second time, stating that John was not ready to lead something of that scale. Halsey began to argue in kind but was cut of by John himself, who agreed with the admiral. This earned him a scowl from the doctor but she did not press the point any further after that. Ascot, who would be leading an all [[prowler]] force dubbed [[Task Force Yama]], let Halsey know she would be confined to the ''Vanishing Point'' for her own safety for the operation's duration. Halsey began to protest this but relented when Cole threatened to ship her back to [[Reach]] should she try to leave the ship.<ref name="HSS5"/> Following this meeting Catherine gave Johnson access to the Spartans' TEAMCOM to facilitate his role as liaison between they and the ODSTs and also made it clear to John that he should give the sergeant's advice a lot of weight—especially when navigating the vagaries of protocol inherent in their attachment to the 21st.<ref name="HSS7"/><ref name="HSS8">''[[Halo: Silent Storm]]'', ''Chapter 8''</ref>

{{Expand-Section}}

On [[2549#September|September 9]] Halsey reflected on the recent [[Second Fall of Arcadia|loss]] of [[Arcadia]], as she had come into possession of a near-complete record of the attack taken from from an orbiting weather satellite.<ref name="HJ72949"/> In her journal she expressed the agony viewing the destruction caused her, noting that she knew some would smirk at the thought of her shrinking from it. As the entire world's surface was mercilessly [[Glassing|glassed]] rather than only portions, she wondered variously whether the planet posed a threat to them, had religious or political value, or was simply designated for sending a message to humanity.<ref name="HJ72949"/> By September 14 Halsey had hacked into the redacted portions of other Arcadia reports.<ref name="HJ91449">''[[Dr. Halsey's personal journal]]'', ''July 14, 2549''</ref> At some point in September the annex in [[CASTLE Base]]'s Omega Wing where Halsey was working was quarantined.<ref name="HRO"/> On [[2549#November|November 7, 2549]], she transferred and authenticated the H-1 specimen's neural pattern to A.I. matrix strata, completing the initiation sequence within normal quantum flux tolerances.<ref name="HJ11749"/><ref name="WaypointCortana">[https://www.halowaypoint.com/en-us/universe/characters/cortana '''Halo Waypoint''' - ''Cortana'']</ref><ref name="HRO">''[[Halo: Reach]]'', ''[[Outpost (level)|Outpost]]''</ref> The newly-made intelligence called herself "[[Cortana]]" and represented a generational leap in volitional A.I. technology.<ref name="HRO"/> Halsey placed a viral termination code in her kernel but then could not tell whether she remained unaware of it or had already isolated and bypassed it.<ref name="HJ11749"/> Halsey also programmed her with ONI's best insurgency software and every ONI computer insurgency routine, as well as the determination to use those code-cracking skills.<ref name="HTFOR25"/><ref name="HTFOR27"/> She first designed and tested these routines on [[Kalmiya]].<ref name="HFS13"/> Only once the process had been debugged and streamlined did she incorporate them into Cortana. Afterward, the brass in [[ONI Section Three|Section Three]] instructed Halsey to destroy any prototype routines—an order which she promptly ignored.<ref name="HFS13"/>  

By [[2551#May|May of 2551]] Catherine had begun to lead the excavation of an ancient [[Forerunner|alien]] [[Babd Catha Forerunner vessel|vessel]] that lay [[Babd Catha Forerunner complex|buried]] beneath the area occupied by ONI's [[SWORD Base]] within the [[Babd Catha Ice Shelf]] in northern [[Eposz]].<ref name="DD3"/><ref name="DD2">[[Data Drop]] [[Data Drop/Two|#2]]</ref><ref name="HRTP">''[[Halo: Reach]]'', ''[[The Package (level)|The Package]]''</ref> Even so, her residence remained in [[Csongrád]] where she also continued to work with Doctor Sorvad on the Visegrád findings.<ref name="DD3"/> On May 8 she was interviewed by analyst [[B.M. Parkes]] so that they might conduct a [[Hemley and Aubourn Behavior Analysis|Hemley and Aubourn behavior analysis]] of her.<ref name="DD3"/> Following the encounter Parkes recorded that she had not been terribly forthcoming and ultimately recommended assigning two to three handlers to her at both sites where she was working. Parkes also was confident she needed to be surveilled were she to be called off-planet, though her leaving Reach was something they and their colleagues strongly discouraged at that time.<ref name="DD3"/> Two days later Halsey noted in her journal that a security issue which she blamed Sorvad for had caused her to begin keeping an eye on the inhabitants of [[Visegrád]] to ensure they didn't disappear thanks to Section Three.<ref name="HJ51051"/> As an insurance policy, she told Stanforth that the people there for valuable for being the only ones with extended exposure to the site under study and as such may need to be studied. She met with Sorvad and he assured her that only certain members of the dig team and a few other "necessary parties" on her side had seen the items recovered from the site. He insisted on continuing the work with only a skeleton crew of his most trusted people and promised he would not tolerate "another [[Farragut Station]]", referring to the communications outpost. Halsey simply nodded but was displeased, wondering if Sorvad might actually know what had happened at Farragut Station in the past and the reason for its relocation.<ref name="HJ51051"/> On [[2552#May|May 15, 2552]] Kalmiya caught a glimpse of several documents in Vice Admiral Stanforth's [[Beta-5 Division|Beta-5]] server which ranged from service order transfers of existing Spartan-IIs to highly-classified non-Spartan-II detachments.<ref name="HJ51551">''[[Dr. Halsey's personal journal]]'', ''May 15, 2552''</ref> This had evidently been going on for years, and Halsey was incensed at having been kept in the dark about it. She resolved to not let this go, and as she had a list of names with [[James Ackerson|one man]] she considered particularly obscene at the top, she planned to send Kalmiya back in as soon as she got a handle on the affairs with Sorvad.<ref name="HJ51551"/> At various points during her time spent beneath the Babd Catha shelf Doctor Halsey kept tabs on a number of individuals and groups, recording her thoughts on each.<ref name="HRTR"/> She noted, for example, that she felt inspired by and grateful for those among the [[Seventh Column]] community who had been willing to reach out to her. Halsey was similarly comforted by those involved with the initiatives "[[Fight the Flood]]" and "[[Be a Hero]]". Other civilians which merited her attention during this period included those of [[Red vs. Blue|RvB]] and [[Halo.bungie.org|HBO]], the former having entertained her on multiple occasions and the latter impressing her enough to make her consider providing the faction with direct access to her internal systems. When the doctor initially caught wind of a training protocol which had seen [[Randall Glass|a]] marine [[Warthog Jumping|lift]] an [[M12 Warthog]] with [[M9 fragmentation grenade|grenades]], she did not believe the reports. Upon seeing video footage of the accomplishment, however, she decided to flag his file for investigation. It was her opinion that though he should be reccomended for the ODSTs, it was too risky to keep him in the field and run the risk of others emulating his foolish actions. And finally, Catherine took care to recognize [[HCFS]], which represented her eyes and ears in the field. At some point during this time she worried she might have a security breach, as a file in her workspace had been opened which she could not recall ever accessing.<ref name="HRTR">''[[Halo: Reach]]'' "[[Tribute Room]]"</ref>

By 1126 hours on July 26 [[SWORD Base]] had come under attack by an {{Class|SDV|heavy corvette}} and Covenant ground forces from the [[Fleet of Valiant Prudence]].<ref name="HROSB">''[[Halo: Reach]]'', ''[[ONI: Sword Base]]''</ref> Following the attack's repulsion Halsey requested permission to debrief with NOBLE Team, the six members of which met her within the base's science wing thereafter. Upon seeing them her suspicions were confirmed: they were [[SPARTAN-III program|Spartan]]s, as incomprehensible as that was to her at the time. Only one of them, [[Jorge-052]], was one of hers. She had already begun conversing with the team's leader, [[Carter-A259]], when Jorge and [[SPARTAN-B312|sixth member]] of the team finally joined them. She was in the midst of telling Carter to dispense with telling her about the recent engagement outside so she could hear about what happened in [[Visegrád]] when Jorge's entrance made her stop mid-sentence to greet him. She couldn't help but ask after the obvious modifications made to his armor before returning to the matter of the [[Visegrád Relay|Visegrád relay]], and Doctor Sorvad's death in particular. From Carter, Jorge, and [[Spartan-B312]] she learned that [[Devoted Sentries|a group of three]] [[Sangheili]] [[Sangheili Zealot|Zealot]]s were likely responsible. The same had ambushed NOBLE Team when they'd arrived at the relay and the one which appeared to be their leader had gotten away from the Spartans. Halsey dismissed mention of Sorvad's daughter [[Sára Sorvad|Sára]] in the interest in maintaining focus on the Elites and what their leader might have escaped with. She bristled at Carter's defense of his order not to pursue the last zealot, worried that it might have stolen valuable ONI excavation data. She let them know about the supposed latchkey discovery Sorvad had made and emphasized its importance, stressing that they should hope a [[data module]] found on his corpse contained what was so important. At this [[Kat-B320]] handed the module over to the doctor through a transaction drawer, as a wall of glass separated her from NOBLE. She let the lieutenant commander know she'd been alerted when she'd tried to access its contents, threatening her with imprisonment for attempting to interfere with her work. This prompted Carter to rush to Kat's defense, citing the [[WINTER CONTINGENCY]] directive and the provision against civilian interference with a Spartan deployment to make the same threat to Halsey. Jorge lingered when the rest of the team began to leave, but Halsey told him they'd talked enough, allowing him to move on as well.<ref name="HROSB"/>

[[Battle Group Leviathan]] arrived at [[Reach]] from [[Sigma Octanus IV]] by [[2552#August|August 12]] so Halsey went on that date to see what had been done to her [[Mjolnir]] units.<ref name="HJ81252">''[[Dr. Halsey's personal journal]]'', ''August 12, 2552''</ref> Replacement parts and possible upgrades were available, though she noted later that day that [[John-117]] would need to be laser scanned for the new cybernetic implants she planned to give him. Once she was aboard his {{Class|Halberd|destroyer}}, the {{UNSCShip|Iriquois}}, [[Jacob Keyes]] came to see her as she had been both hoping and dreading.<ref name="HJ81252"/> They were able to talk about Miranda, his recent "[[Keyes Loop]]", the Spartans (including their operational records, which she showed him), and what little she could prematurely disclose about [[Operation: RED FLAG]].<ref name="HJ81252"/><ref name="HTFOR29">''[[Halo: The Fall of Reach]]'', ''Chapter 29''</ref> When they parted they wished one another the best on their respective missions and Keyes even kissed her on the cheek when she offered her hand to shake.<ref name="HJ81252"/> By 1100 hours later that day she was present for Keyes' debriefing at [[Camp Hathcock]], sitting on a panel which included herself, Admiral Stanforth, and [[Colonel]] [[James Ackerson]].<ref name="HFORI">''[[Halo: Fall of Reach]]'', ''[[Halo: Fall of Reach - Invasion|Invasion]]''</ref> A little over ten minutes later she met John within one of the camp's military complexes—where he had just finished his own debriefing.<ref name="HTFOR24">''[[Halo: The Fall of Reach]]'', ''Chapter 24''</ref> She was sitting in an overstuffed chair when he returned to the debriefing lounge and her surprise presence caught him off guard.<ref name="HTFOR24"/> She asked how he was doing, making sure to not give any suggestion that [[Battle at Szurdok Ridge|all was not well]] on Reach at that moment, as it had been decided the Spartans should be kept in the dark for the time being so that RED FLAG might not be compromised.<ref name="DD5">[[Data Drop]] [[Data Drop/Five|#5]]</ref><ref name="HTFOR24"/> In the few minutes they had Halsey told him about the upcoming procedures planned for him and gave his head a cursory [[Wikipedia:Magnetic Resonance Imaging|MRI]].<ref name="HJ81252"/> John asked after [[Franklin Mendez|Mendez]] and all the others the two of them had called family and Halsey shared what little she knew without giving heed to protocols or security clearances. They then sat together quietly for a time.<ref name="HJ81252"/> John was enthusiastic about the victory at [[Sigma Octanus system|Sigma Octanus]], so she asked whether he would like another victory and perhaps the biggest they'd ever had at that.<ref name="HTFOR24"/> She left things with him there, however, and just offered that they'd be speaking soon. Turning to the [[military police]] attendant waiting at the lounge's entrance, she instructed him to open the doors so she could take her turn speaking to the committee of twelve naval officers, ONI and otherwise.<ref name="HTFOR24"/> Two days later Halsey was within [[SWORD Base]] again when it saw further bombardment from the [[Covenant]].<ref>''[[Halo: Reach]]'', ''[[Long Night of Solace (level)|Long Night of Solace]]''</ref> On [[2552#August|August 23]] the Spartans of [[NOBLE Team]] were informed they were to redeploy to SWORD Base for a torch-and-burn operation meant to keep Doctor Halsey's excavation data from falling into enemy hands.<ref name="HRNA"/> Unbeknownst to them, they were actually being recalled there so the doctor could use them as couriers for the fragment of Cortana which would need to be reunited with the rest of her before the ''Pillar of Autumn'' departed.<ref name="HRTP"/> At some point prior to their eventual arrival on August 30, while within her lab at Babd Catha Catherine reviewed what she knew about the team's members with Cortana, seeing as one of them would need to personally take possession of the fragment for delivery.<ref name="HRTP"/><ref name="ASWR"/><ref name="HJ83052"/> Cortana elected to give that role to [[Spartan-B312]], the team's newest member—a decision Halsey agreed with.<ref name="ASWR">''[[Halo: Reach ViDoc: A Spartan Will Rise|A Spartan will Rise]]''</ref>

On [[2552#August|August 27]] Catherine Halsey and Jacob Keyes met with twenty-five of the remaining Spartan-IIs at 0800 hours underneath the Highland Mountains [[Reach FLEETCOM Military Complex|FLEETCOM complex]] to brief them on [[Operation: RED FLAG]], as Admiral Stanforth had requested she do.<ref name="HTFOR26"/> There, in the same amphitheater in which they had been brought as children thirty-five years prior, she asked them to disregard normal protocol and ask any questions they may have during her presentation. She explained that RED FLAG was to be executed in four phases. First, a Covenant ship would be disabled. Then, the Spartans would board it and crack its navigation database. John interrupted her at this point to ask if mission specialist personnel would help with the Covenant computers and she assured him that would be addressed soon. The mission's third phase was to involve taking the captured ship to the Covenant "[[High Charity|home world]]", and its fourth would see one of its leaders captured and brought to UNSC space. John spoke up again to question the wisdom of capturing a [[San'Shyuum|prophet]] rather than killing them, so Halsey addressed his concern by pointing out that killing one could trigger an escalation. Taking a [[hierarch]] prisoner might allow the UNSC to force a truce. Intelligence indicated that the three hierarchs at the apex of the Covenant spent their time either at the hegemony's mobile capital city ''[[High Charity]]'' or aboard either {{Class|CSO|supercarrier}}s or {{Class|CAS|assault carrier}}s.<ref name="DD5"/> Capturing an assault carrier or supercarrier would be preferable because with luck one of the [[San'Shyuum]] High Prophets would be aboard and a trip to ''High Charity'' would be unnecessary.<ref name="DD5"/> Hesitantly, the doctor shared that ONI was predicting only months remained before the enemy found [[Earth]] and moved against it. Even so, she had persuaded Stanforth and FLEETCOM to not order any of them to join this operation—all would be volunteers. Without a second through every Spartan present stood upon hearing this, and Catherine thanked them. As she stepped away from the podium she'd been addressing them from she said she and Keyes would meet with each of them individually within a few days to continue their briefing. Each of them needed to be given Mark V Mjolnir and shown how to get their "[[Cortana|computer experts]]" on board the alien ship, after all.<ref name="HTFOR26">''[[Halo: The Fall of Reach]]'', ''Chapter 26''</ref>  

In order to pull RED FLAG off, it had been determined that a colony of significant value to the Covenant and boasting many [[Forerunner|ancient alien]] artifacts would in all likelihood need to be sacrificed in order to draw the required Class-Five assets, possibly with hierarchs, in so that Spartans could infiltrate them. The best shot at taking over a large ship would come after a fleet believed it had secured a major victory.<ref name="DD5"/> Given the current situation on Reach, ONI had decided to make the most of a losing fight and enact RED FLAG there. It was for this reason that not a one of the twenty-five Spartans was yet aware that [[Reach]] was already [[Fall of Reach|under seige]], largely thanks to the efforts of Halsey and Stanforth, who had been making sure to keep them well away from the primary target sites.<ref name="DD5"/> Later that day Halsey reflected on the meeting in her journal, being hopeful for the Spartans' ability to secure a temporary peace that would but humanity time.<ref name="HJ82752"/> She expressed her thrill at seeing so many of them together once again and mourned for those who had died years past, truly surprised at how emotional the gathering had made her. She was confident they were ready, but still resolved to appear strong for their benefit. She noted that the [[MJOLNIR Powered Assault Armor/Mark V|Mark V]] armor they'd soon be gifted with was one small operation and a few tests from completion. With only a few days left before she expected to learn whether all her discoveries and sacrifices had been worth it, she closed that day's entry wishing there was time to properly analyze her feelings and reminding herself that four small tasks still remained to complete.<ref name="HJ82752">''[[Dr. Halsey's personal journal]]'', ''August 27, 2552''</ref> By this point she had begun splitting Cortana into separate programs in order to juggle the [[Visegrád]] findings with RED FLAG.<ref name="DD5"/> Cortana, for her part, was continually updating her separated portion and would keep doing so until the last possible moment. Catherine was excited to see how she and John took to one another.<ref name="HJ82752"/> She had assured Stanforth that Cortana remained fully functional even with a large portion of her processes excised.<ref name="DD5"/>

By 0600 hours on August 29 Catherine and others were waiting for John at the "Prep and Recovery" area of [[Military Reservation 01478-B]].<ref name="HTFOR27">''[[Halo: The Fall of Reach]]'', ''Chapter 27''</ref> She entered a prefabricated structure there just as the Spartan was having the back of his neck swabbed to tell him it would only take a moment to upgrade a few components of of his [[neural interface]].<ref name="HTFOR27"/> She asked him to lie back and remain still, and once the procedure began she assisted to some degree with fusion of the new components.<ref name="HTFOR27"/><ref name="HJ82952">''[[Dr. Halsey's personal journal]]'', ''August 29, 2552''</ref> She took a brief moment to note in her [[Dr. Halsey's personal journal|journal]] that the surgery had gone flawlessly and that his recovery would be well within regenerative parameters.<ref name="HJ82952"/> At that moment tests to evaluate the integration of the [[MJOLNIR Powered Assault Armor/Mark V|Mark V]] Mjolnir and A.I. were planned to commence in around three hours.<ref name="HJ82952"/> Once John was finished receiving his upgrades she asked him to follow her to a field command dome on the reservation's range.<ref name="HTFOR27"/> After presenting her credentials to the [[military police]] standing guard and submitting to identification scans she led John in to introduce him to the Mark V armor.<ref name="HTFOR27"/> Halsey asked him to put it on, averting her eyes as he did so with assistance from two technicians. She explained hundreds of minor technical improvements had been made compared to the [[MJOLNIR Powered Assault Armor/Mark IV|Mark IV]] and that she would send the specifications to him later. The two most significant additions, she added, were the armor's [[energy shield]] system and a weave of memory-processor super-conductor which allowed it to carry an A.I. She taught him how to adjust the shielding and assured him he'd get to see how much punishment it could take soon (she herself had suggested live rounds for the upcoming testing) before finally introducing him to [[Cortana]].<ref name="HTFOR27"/><ref name="HTFOR28"/> The A.I. had been provided with the very best [[Sangheili (language)|Covenant language]] [[translation software]], Halsey said, so that she could infiltrate their computer and communications systems. Halsey promised Cortana would not be able to control his armor when John asked, though she would improve his reaction time. It was her explanation that, like him, Cortana would do whatever was necessary to complete [[Operation: RED FLAG|their mission]] that relieved the Master Chief. He knelt so Halsey could insert her [[Data crystal chip|memory processor matrix]] into his helmet and then watched with great interest as the Spartan and A.I. met one another for the first time.<ref name="HTFOR27"/>

Upon entering SWORD Base the surviving members of NOBLE were led at [[Cortana]]'s direction to a tram which would carry them one-and-a-half kilometers east and around two thousand feet underground, where Halsey's laboratory was.<ref name="HRTP"/> Once the four of them had climbed aboard she appeared on a monitor and apologized to [[Carter-A259]] for the unusual security measures which had kept them from fully knowing what to expect at the base. He started to remark on the fact that she'd been listed as having died, but the doctor dismissed the casualty reports relating to her as false before he could finish and said she only wished the same could be said for the rest of his team, both [[Jorge-052]] and [[Kat-B320]] having been killed within the last few weeks. She offered what might have been a small comfort in sharing that the [[data module]] delivered by Kat had unlocked the secrets of her nearby [[Babd Catha Forerunner vessel|excavation]]. She then explained that their orders to destroy all sensitive material at the base had been overridden, as they had always been nothing more than a pretext to bring them to her so that they could take possession of this vital data and deliver it elsewhere. Carter argued that he would need to confirm this change with Colonel [[Urban Holland|Holland]], but Halsey assured him he would be briefed and said that they belonged to [[ONI]] now. As soon as NOBLE team first laid eyes on the [[Babd Catha Forerunner vessel|massive ship]] Halsey explained that it was [[Forerunner|alien]] but not Covenant in origin and that thanks to Kat's data its decryption was nearly complete. Carter urged her to have it ready when they reached her but the doctor insisted the decryption was still underway and, should they allow any of it to be left buried there, they'd be burying [[Human|mankind]]'s [[Installation 04|best chance]] for survival. Covenant attackers soon began encroaching on her lab and she implored the Spartans to defend it in order to buy her all they time they could. As NOBLE Team fought off successive waves of enemies Halsey occasionally updated them on the progress of the data's final decryption, and as soon as it was complete she let them know she was opening the laboratory's door. Within, she explained to them that [[Cortana]] was the important data's custodian and had been the one to choose them as her couriers. [[Emile-A239]] found the notion strange, and at that Halsey made it known that ''this'' A.I. was special. She then told them they were to carry her to the [[Asźod ship breaking yards|ship-breaking yards]] in [[Asźod]], where they would find the {{Class|Halcyon|light cruiser}} {{UNSCShip|Pillar of Autumn}} waiting to spirit her away. Carter indicated his understanding of the mission, but Halsey made sure he understood the importance of it, claiming that humanity's annihilation was all but certain unless they could gleam some way to stop the Covenant from the information the ancient ship had provided.<ref name="HRTP"/> Once she'd recieved Cortana's permission to do so, she took her offline so she could be transferred to an [[armored matrix]].<ref name="HRTR"/> With that, she removed it from where it had been plugged in and handed it to [[SPARTAN-B312]].<ref name="HRTP"/> She said that Cortana had chosen him specifically to carry her and made him confirm he'd taken secure possession of the matrix before finally letting go.<ref name="HRTP"/>

However, this changed when Spartans [[Frederic-104]], [[Kelly-087]], [[Vinh-030]], [[Isaac-039]], and [[Will-043]] appeared at the entrance to CASTLE Base. With the firepower to potentially fight their way out, the possibility of surviving CASTLE Base's destruction became available. She gave emergency aid to the Spartans for their injuries, but a data anomaly detected by her accompanying AI, [[Cortana]]'s "older sister" [[Kalmiya]], attracted Dr. Halsey's attention.

Over the course of the next five days, the Spartans and Dr. Halsey searched the mines, looking for either an exit or what Dr. Halsey would dub ''"the most important discovery of the millennium"''. On the fifth day, Fred discovered an entrance into a large [[Forerunner]] [[Menachite Forerunner complex|structure]], and within, a [[Forerunner crystal|spacetime-warping crystal]]. However, the acquiring of the crystal sent a spike of neutrino radiation, attracting the attention of the Covenant. Their location was now threatened by Covenant forces.

[[File:HM-MendezHalsey.png|thumb|200px|right|Halsey and Mendez inside Shield World 006.]]

In mid-[[2558#February|February of 2558]] Doctor Halsey arrived at the [[shield world]] [[Requiem]] in the [[Epoloch system]] aboard the {{Class|Sahara|heavy prowler}} {{UNSCShip|Aladdin}}.<ref name="H4SOC">''[[Halo 4]]'', ''[[Spartan Ops]]'', ''[[Catherine]]''</ref> There, she was delivered to the {{UNSCShip|Infinity}}, which had arrived just days earlier for its [[Second Battle of Requiem|second]] excursion to the massive [[Forerunner]] planetoid. Four marines turned her over to Captain [[Thomas Lasky]], to whom Catherine demanded that she be freed from her restraints on the grounds that she would not walk around the ship ''she'' built with her hands cuffed. The captain consented and [[Spartan]] [[Paul DeMarco]] proceeded to undo them, at which point the doctor told Lasky to take her to an [[Requiem translocation artifact|artifact]] which had been brought aboard the ship on February 10 and unexpectedly caused a number of problems for it.<ref name="H4SOA">''[[Halo 4]]'', ''[[Spartan Ops]]'', ''[[Artifact (Spartan Ops)|Artifact]]''</ref><ref name="H4SOA"/> Among these was the disappearance of [[Henry Glassman]], the ''Infinity'''s chief engineer, who had been unwillingly [[Slipspace translocation|teleported]] by the artifact to an unknown location.<ref name="H4SOC"/><ref name="H4SOA"/> Lasky had been forced to request Halsey's aid following the loss of Glassman.<ref name="HM179">''[[Halo Mythos]]'', ''page 179''</ref> As she approached the artifact in question she asked if any other unexplained reactions had followed.<ref name="H4SOC"/> She was told that none had, but Lasky still cautioned her once she touched it, fearing the same could happen to her.

{{Expand-Section}}

Parangosky had sent Halsey a note in which she asked for her aid in the matter, appealing to her on a professional level to protect ''Infinity'' and its crew despite her less than ideal conditions.<ref>'''Halo 4''', ''Infinity Briefing Packet''</ref> Many of the crew had mixed feelings about bringing her aboard, [[Sarah Palmer]] suspicious of her and feeling she might try to sabotage the ship, [[Thomas Lasky]] sharing her worries but feeling there was no choice. Halsey was unimpressed by the Spartan-IVs assigned to guard her, wryly questioning their competence and general attitude. With a few gestures from her, the artifact began reacting to her, she translating its actions as signs that she should examine the ship's engines. Upon doing so, her conclusion was that the artifact was "communicating" with multiple parts of the ship and transmitting to Requiem. Some time later, she analyzed a Forerunner [[beam emitter|beam tower]] encountered by [[Fireteam Crimson]] in the location codenamed [[Two Giants]].<ref>'''Spartan Ops''', [[S1/Catherine|S1E3 ''Catherine'']]</ref>

By [[2558#March|March 2558]], the {{UNSCShip|Vociferous}} was put in charge of finding Halsey and 'Mdama.<ref>'''[[Halo: Escalation]]''', ''[[Halo: Escalation Issue 1|Issue #1]]''</ref> At some point on Requiem, Jul's forces had recovered a Forerunner [[Requiem communication artifact|artifact]] that would be able to communicate with the Forerunner-derived engine systems of ''Infinity'', and therefore the artifact would be able to blockade the engines of ''Infinity'' and allow Jul to steal the other half of the Janus Key. On [[2558#July|July 15, 2558]], Halsey made a personal journal entry on her views of the Forerunners and recent events.<ref name="HE13">'''Halo: Escalation''', ''[[Halo: Escalation Issue 13|Issue #13]]''</ref> The next day, Jul's forces [[Battle of Oban|attacked]] [[Oban]], a human colony in the midst of settlement, as advocated by Halsey. She believed that a bold move was the only way to attract ''Infinity''. After the attack failed, 'Mdama's lieutenants called for Halsey's head, however Jul seemingly defended her actions. After ''Infinity'' attempted to enter slipspace for [[Galileo II]] base, 'Mdama's Forerunner artifact forcefully brought it back into normal space and trapped the vessel in an uncharted system. Aboard a {{Class|CCS|battlecruiser}}, Halsey informed Jul that they did not need to attack the ship, as the crew of ''Infinity'' would now be willing to hand over the other half of the Janus Key directly.<ref name="HE13"/>

Some time after 'Mdama had left for the planet, Halsey contacted him from the ''Song of Retribution'' and urged him to focus on the acquisition of the Janus Key rather than the rebellion among his ranks. In response to the developing situation, Jul fulfilled Halsey's earlier request and allowed her to take a Phantom to the surface of Aktis IV.<ref name="HE15">'''Halo: Escalation''', ''[[Halo: Escalation Issue 15|Issue #15]]''</ref> Halsey and a convoy of Phantoms traveled to an island on Aktis IV to meet [[Unidentified Sangheili Minor|a defector]] from 'Nyon's forces. After the defector reluctantly gave the half of the Janus Key he had stolen from 'Nyon's base to Halsey, the doctor and her Sangheili escorts prepared to return to ''Song of Retribution''. After Jul had most of Halsey's convoy depart to battle UNSC forces elsewhere on the island, Halsey and the remaining Covenant forces were ambushed by Spartans Palmer, Thorne, and [[Naiya Ray|Ray]]. Palmer pursued Halsey and her guard into the jungle, while the other Spartans eliminated the surviving Covenant forces. After killing her guard, Palmer captured Halsey and led her through the jungle. The two began to argue, with Palmer accusing her of being a traitor and war criminal, and Halsey calling Palmer out for acting as Admiral Osman's puppet and stating that ONI turned her into a convenient scapegoat. As Palmer's judgement became momentarily clouded, Halsey ran off into the jungle. Palmer attempted to pursue, but she was injured and knocked into a crevice by a nearby [[Type-58 Harvester|Harvester]]. Halsey contacted 'Mdama and he had a Phantom return her to his flagship.<ref name="HE16">'''Halo: Escalation''', ''[[Halo: Escalation Issue 16|Issue #16]]''</ref>

The carrier traveled through the portal and arrived into the Record, where Halsey, along with the other humans who had infiltrated the carrier, were detected by a [[Contender-class artificial intelligence|Contender-class]] [[custodian]].<ref name="HE20">'''Halo: Escalation''' ''[[Halo: Escalation Issue 20|Issue #20]]''</ref> After ''Retribution'' was forcefully brought through a portal to a large chamber, Halsey, 'Mdama, and a contingent of Zealots traveled to a lower platform, where Halsey addressed the ancilla and told it that she was selected by the Librarian and her possession of the Janus Key was proof. However, the AI was skeptical of her claims, claiming Halsey could've obtained the Key by force and especially pondering why the other humans felt the need to conceal themselves. The AI had its Sentinels bring the other humans down to the platform, and stated its intent to let each human have a chance to account for its presence at the installation, despite Halsey's assertions that there was nothing to discuss as she had the Janus Key. As she continued to argue with the AI and Glassman, an impatient Zealot attacked a Sentinel, leading to a conflict on the platform. Frustrated, the AI removed the flooring from under the feet of the Sangheili, with Tanaka, Palmer, and Glassman remaining on one platform and Halsey standing on another, 'Mdama managing to grab its edge just in time.<ref name="HE21">'''Halo: Escalation''' ''[[Halo: Escalation Issue 21|Issue #21]]''</ref>

By October 23 the ''Infinity'' had arrived in the [[Crow's Eye Nebula]].<ref name="H5GBT"/><ref name="WaypointLinda-058">[https://www.halowaypoint.com/en-us/universe/characters/linda-058 '''Halo Waypoint''': ''Linda-058'']</ref><ref name="TD">[[Troy Denning]] on Twitter [https://twitter.com/TDenningauthor/status/932052034701942784]</ref> At 0630 hours that day [[Linda-058]], [[Kelly-087]], [[Frederic-104]], and [[John-117]] were declared absent without leave, having made an unsanctioned departure from the nebula in [[ONI Acrisius|a]] stolen {{Class|Winter|prowler}}.<ref name="H5GG"/><ref name="H5GBT"/> Spartan Palmer escorted Halsey to the ''Infinity'''s bridge later that day, where she immediately began pressing the matter of Cortana once more to the captain, stressing how dangerous she had become through accessing the Domain and taking control of [[Guardian Custode|devices]] which had begun to cause damage on a number of colonies.<ref name="H5GG"/> Lasky informed her that the Master Chief had reported being contacted by Cortana, which Halsey saw as potentially disastrous. She was then told that he'd gone in search of her and was shocked at the notion that Lasky would have let him go, but he explained that John was not acting independently. Halsey began to speak on why John was unequipped to deal with Cortana as a threat but was interrupted by [[Roland]], who until that point had been unaware of her continued survival. He questioned why the doctor was so quick, in his mind, to label Cortana a threat or a danger, seeing as she was the one who had created her to begin with.<ref name="H5GG">''[[Halo 5: Guardians]]'', ''[[Glassed|Glassed]]''</ref> Two days later Fireteam Osiris was deployed once again, but this time with the goal of apprehending Blue Team and the stolen [[prowler]].<ref name="H5GG"/><ref name="HFWR">''[[Halo: Fractures]]'', ''[[What Remains]]''</ref> The AWOL Spartans had been followed to [[Meridian]], a moon of [[Hestia V]].<ref name="H5GG"/> Osiris failed to stop them, as they managed to board a [[Guardian Custode]] which had long been buried beneath the moon's surface and had now slipped away.<ref name="H5GE">''[[Halo 5: Guardians]]'', ''[[Evacuation]]''</ref> As such, The fours were forced to return to the ''Infinity'' empty-handed.<ref name="H5GE"/> The day after this Locke and Lasky met Palmer and Halsey on the bridge and Locke let it be known that a construct they'd met on Meridian calling itself the [[Warden Eternal]] had confirmed the doctor's theory that Cortana was behind the Guardians' ongoing reactivations.<ref name="H5GR">''[[Halo 5: Guardians]]'', ''[[Reunion]]''</ref> Halsey then turned their attention to [[Sunaion]], a religious site on [[Sanghelios]] where she had discovered another Guardian still lay buried. Palmer and Roland took over from there, explaining that if they could feed coordinate data from the Meridian Guardian to the one on Sanghelios it could lead them right to [[Genesis|wherever]] Blue Team had vanished to.<ref name="H5GR"/>

[[File:H5G HalseySanghelios.PNG|right|thumb|350px|While in the Arbiter's camp, Doctor Halsey's amputee status was taken by the [[Unggoy]] and self-proclaimed biologist [[Gribyam]] to support [[Kat-B320|theories]] that [[human]] females signal maturity by losing appendages.<ref name="H5GAMI"/> He further hypothesized that she would soon begin to release spores and spin a cocoon of "rich meat-silk".<ref name="H5GAMI"/>]]

Palmer had planned to get the doctor off-world once the [[Battle of Sunaion|attack]] on the ocean city began, but she and Halsey eventually arrived at the battle near its end.<ref name="H5GBTS"/><ref name="H5GBOS">''[[Halo 5: Guardians]]'', ''[[Battle of Sunaion (level)|Battle of Sunaion]]''</ref> The Guardian had risen above the waves by that point and was preparing to depart, so Palmer meant to pick up Osiris to deliver them to it before it did so.<ref name="H5GBOS"/> Halsey could not bear to even keep her eyes open for very long as the conflict rained plasma fire all around them. Palmer managed to get the other Spartans to the Guardian, but in the process their Pelican's left thruster was struck by a [[Type-54 Banshee]]'s [[fuel rod]] and set ablaze. Though it seemed as if Palmer would be able to get them out of there regardless, the Guardian then sent out an [[attenuation pulse]] which neutralized the dropship's power and sent it spiraling toward the [[Csurdon Sea]] below.<ref name="H5GBOS"/>

By [[2559#January|January 24, 2559]], they were still on the run, performing erratic jumps to evade discovery.<ref name="lootcrate12"/> That day, at just after 1204 hours, Halsey was approached by a Spartan from [[Fireteam Apollo]] with the serial number [[92738-61842-LC]]. This individual had been tasked by Captain Lasky with investigating what was being dubbed "the Guardian Incident". Halsey pointedly asked how they had gotten clearance to talk with her and was made aware of the priority-one directive given to them by the captain. After then confirming she was being recorded, the Spartan informed her they were there to talk about [[Cortana]]. Halsey was interested to hear what their investigation had unearthed so far, but they reported not being authorized to share anything further than their having concluded that the cognitive duress and strain Cortana had sustained since the discovery of [[Installation 04]] was partially responsible. The Spartan's first questions for the doctor concerned Cortana's creation, and Halsey was soon defending her actions incumbent in that process. She also refused to reveal what had become of the clones of herself she had made, claiming that was still classified even for them. Asked what she thought the best explanation for what had happened was, Halsey recalled Cortana's first words and theorized she was simply doing she had to in order to keep "the game" from ending. Halsey then quoted the Greek philosopher [[Wikipedia:Epictetus|Epictetus]] and suggested Cortana was the answer to his thought experiment regarding the harm in saying "Tomorrow you will die," while kissing one's child. When her interviewer asked what she thought the solution to stopping her was, Catherine ignored the question since she doubted coming up with that would be part of a Spartan's directive and was convinced she'd been locked away for that purpose. 92738-61842-LC countered that she'd been locked up because of her repeated protocol violations, which only led to further argument and  the Spartan finally choosing to take their leave. Before they went, Halsey shared the [[Cortana Letters#First letter|last thing]] Cortana had said to her.<ref name="lootcrate12"/> The Spartan asked what her words were supposed to have meant, but Halsey could only say that she had been hoping they were able to explain them to her.<ref name="lootcrate12"/><ref group="note">What Halsey indicated Cortana had last said to her is quoted from the first of the [[Cortana letters]], a series of emails produced prior to the release of ''Halo: Combat Evolved''. Whether or not Cortana said the things she did to Halsey prior to her slipping away from [[Eridanus Secundus]] in [[2552]] or at some point after, perhaps following her accessing of the [[Domain]], is unknown.</ref> On [[2561#September|September 19, 2561]] Doctor Halsey made modifications to [[John-117|John]]'s [[MJOLNIR Powered Assault Armor (GEN3)|third-generation]] Mjolnir, itself having first been created on [[2559#February|February 10, 2559]].<ref name="DH">''[[Discover Hope]]''</ref><ref group="note">[[Frank O'Connor]], franchise creative director at [[343 Industries]], may have indicated on Twitter that Halsey will receive some sort of replacement arm in the future, stating "She can absolutely have an arm as soon as it's safe to do so."</ref><ref group="note">At some point following the cessation of the war with the Covenant Doctor Halsey eulogized [[Spartan-B312]] of [[NOBLE Team]], commemorating his sacrifice in laying down his life so that the {{UNSCShip|Pillar of Autumn}} could escape [[Reach]] with [[Cortana]]. Thanks to him, [[Installation 04]] was discovered and the events which led to the Covenant's [[Great Schism|downfall]] were set in motion. This dialogue plays at the [[Lone Wolf|end]] of ''[[Halo: Reach]]'' while the planet is shown to be [[Terraforming|recovering]] on [[2589#July|July 7, 2589]], but the precise date for her words cannot be definitively determined.</ref>

[[File:KatCarterHalsey.jpg|thumb|right|275px|Halsey addresses [[Carter-A259]] and [[Kat-B320]].]]

Above most of her compatriots in terms of both intelligence and knowledge, Halsey prefers to perform her most important work personally, rarely entrusting particularly significant scientific tasks to others. She often assumes a certain ownership over her work, most prominently seen with her referring to the Spartan-IIs as "her" Spartans and reacting negatively to others co-opting her work. Halsey is keen to note any flaws she finds in her colleagues' work, and quick to point out when she considers someone unqualified.<ref name="Composer logs"/><ref name="journal"/> However, she also has an eye for talent and will give credit for any accomplishments she sees as remarkable.<ref name="journal"/> It is not uncommon for her to have respect for someone and yet also dislike them, as shown in the cases of her student [[Ellen Anders]]<ref>'''Dr Halsey's journal''': (Halsey: "If that Anders girl was still around, she would have come in handy right about now. She was always so difficult, but this has, without a doubt, become a shared interest.")</ref> and the Spartan-III [[Kat-B320]].<ref>'''[[Halo: Reach ViDoc: A Spartan Will Rise]]''': (Halsey: "Kat, Noble Two. She is brilliant. There are no technical hurdles she can't overcome. But her curiosity borders on insubordination."</ref> Halsey is an atheist, lacking belief in the existence of any god.<ref>'''Halo: Ghosts of Onyx''', ''page 157''</ref>

**''[[Terminal/Halo: Combat Evolved Anniversary|Terminals]]''

[[Category:Humans|Halsey, Catherine]]