Catherine Halsey: Difference between revisions

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*Black {{C|formerly}}<ref name="HTFORTAS">''[[Halo: The Fall of Reach - The Animated Series]]''</ref>

*CI-10141-026-SRB4695{{Ref/Reuse|HTFOR6}}

[[File:Halsey self portrait.jpg|thumb|right|300px|This self-portrait was sketched by Halsey at the age of eighteen, just a few months after she began her work on Reach.{{Ref/Reuse|HJ8810}}]]

Catherine Elizabeth Halsey was born on [[2492#March|March 19, 2492]] within the colony of [[Endymion]]'s coastal city of [[Port Vernon]].{{Ref/Reuse|WaypointCatherineHalsey}} While an impressionable young child her father recited to her every adventurous tale of [[Wikipedia:L. Frank Baum|L. Frank Baum]]'s [[Wikipedia:Land of Oz|Oz]]<ref name="HJ9447">''[[Dr. Halsey's personal journal]]'', ''September 4, 2547''</ref> At this age she was already contemplating ideas having to do with [[artificial intelligence]]s and their longevity.{{Ref/Reuse|HJ9447}} As an adolescent she was smarter than her parents and was continually reading, learning, and talking, being eager to share her knowledge with anyone who would listen.<ref name="HTFOR25">''[[Halo: The Fall of Reach]]'', ''Chapter 25''</ref> Among the works Halsey read at some point was an [[English]] translation of [[Wikipedia:Dante Alighieri|Dante]]'s ''[[Wikipedia:Inferno (Dante)|Inferno]]''.{{Ref/Reuse|HG18}} The first game of [[chess]] Catherine played with her mother was the only one she ever lost to her.<ref name="HJ11749">''[[Dr. Halsey's personal journal]]'', ''November 7, 2549''</ref> Upon beating her daughter she had said, in [[Human languages|Italian]], "When the game is over, the king and pawn go into the same box."{{Ref/Reuse|HJ11749}} At a young age, Halsey was sent to the elite academy [[Endymion Gifted]], where she continued to defy educatory standards. She was eventually afforded a trip to [[Circumstance]] in [[2501]] from the Dean of Biological Science at [[Koletre-Browning University]], who completely funded her education until the completion of her second doctoral thesis sometime after her fifteenth birthday in [[2507]].{{Ref/Reuse|WaypointCatherineHalsey}} While working on that second thesis, Halsey learned various [[Wikipedia:Command-line interface|line command]]s, long discarded and forgotten due to their archaic nature, with which she could interact with computer programs.<ref name="HFS13">''[[Halo: First Strike]]'', ''Chapter 13''</ref>  

On [[2513#June|June 19, 2513]], Doctor Halsey settled on a new name for the project.<ref name="HJ61913">''[[Dr. Halsey's personal journal]]'', ''June 19, 2513''</ref><ref name="H61913">[[343 Industries|Halo]] on Twitter 06/19/2513 [https://twitter.com/Halo/status/215143433965273088]</ref> Stanforth had seemed to hint that rechristening the project would serve to distance it from the failures of ORION.{{Ref/Reuse|HJ61913}} After having [[Jorjet]] and [[Déjà]] (an A.I. created to assist her with the program) give her a refresher on military history which produced a number of contenders, she decided "SPARTAN" best represented the project's aims.{{Ref/Reuse|HJ61913}}{{Ref/Reuse|HSS20}} The [[Wikipedia:Sparta|Spartans]] of [[Wikipedia:Ancient Greece|Ancient Greece]] had been known for their legendary training of young boys and eugenic customs, and the [[Wikipedia:Battle of Thermopylae|defense of Greece]] made at [[Wikipedia:Thermopylae|Thermopylae]] was a well-known and cherished tale within the military community.{{Ref/Reuse|HJ61913}} Coincidentally, Halsey did not fail to note, her project had originally been funded for three hundred candidates. In order to honor the sacrifices made by the men and women of the original ORION effort, she opted to call the project "[[Spartan-II Program|SPARTAN-II]]", preserving its status as the second iteration of that first effort.{{Ref/Reuse|HJ61913}} In [[2515]], Halsey was officially named a scientific advisor for ONI.{{Ref/Reuse|WaypointCatherineHalsey}}

[[File:FORAS HalseyKeyesHan.png|350px|right|thumb|It only took one brief encounter between Halsey and Keyes as they both came out of cryostasis for her to crystallize their roles and the rules of conduct, making him understand she was in charge despite being a [[civilian]].{{Ref/Reuse|HTFOR1}}]]

By [[2517#July|July 21, 2517]], Halsey had been provided with her own team, to which she delegated much of the responsibly for screening Outer Colonies candidates for SPARTAN-II.<ref name="HJ72117">''[[Dr. Halsey's personal journal]]'', ''July 21, 2517''</ref> She did this so it might be completed within a reasonable time frame and so that she could personally focus on processing those from a single region of space: [[FLEETCOM Sector Four|Sector 4]].{{Ref/Reuse|HJ72117}} The children from this [[sector]] which met the criteria Halsey had identified in her original study had files assembled personally by her.{{Ref/Reuse|HTFOR2}} In total, one hundred and fifty subjects were to be considered. The Spartan-II program, of which Halsey was the chief scientist and administrative overseer, had only been granted facilities and funding for half that number, however, so only seventy-five would ultimately be selected.{{Ref/Reuse|HTFOR2}}{{Ref/Reuse|HO4}} And even then, an ONI representative reminded Halsey that not all would make it through the [[Project ASTER|augmentation procedures]] when the time came for that.{{Ref/Reuse|HTFOR3}} Vice Admiral Stanforth had agreed to lend Halsey a [[diplomatic shuttle]] called the ''Han'', provided that she agreed to at least one naval officer accompanying her.{{Ref/Reuse|HTFOR1}} Halsey was given free reign to choose her attaché and after reading through the file of one [[Lieutenant (disambiguation)|Lieutenant Junior Grade]] [[Jacob Keyes]], she requested him based on his demonstrated ability to keep a secret. Keyes was then, without any explanation provided to him as to why, assigned to pilot the ''Han'', protect the doctor, and otherwise stay out of her way.<ref name="HTFOR1">''[[Halo: The Fall of Reach]]'', ''Chapter 1''</ref>{{Ref/Reuse|HJ72117}} On July 21 Halsey wrote in her journal that she was considering recommending him for permanent reassignment to her staff.{{Ref/Reuse|HJ72117}} The ''Han'' also came with its own dedicated artificial intelligence by the name of [[Toran]].{{Ref/Reuse|HJ72117}}

[[File:Halseyrecruits.png|thumb|right|350px|Dr. Halsey looks over the profiles of the abducted children.]]

[[File:SquadLeaderPromotion.png|thumb|350px|right|Halsey and Mendez meet with John.]]

[[File:FORTAS HalseyAlert.PNG|thumb|right|350px|.]]

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 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/Reuse|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/Reuse|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/Reuse|ILBPM}}{{Ref/Reuse|ILB12}}{{Ref/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]].}} While visiting [[Serin-019]] before the procedures commenced the girl asked her how different she would feel when she woke up.{{Ref/Reuse|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/Reuse|HG15}}

[[File:TFORAS HalseyDeja.PNG|thumb|right|350px|Halsey and Déjà.]]

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/Reuse|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/Reuse|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/Reuse|HTFOR9}}

[[File:TFORAS HalseyWallace.PNG|thumb|350px|right|Captain Wallace told Doctor Halsey that he might have had her removed from his ship's bridge had its bulkheads not been sealed, in response to what he saw as outbursts against his orders from someone with no combat experience.{{Ref/Reuse|HTFOR12}}]]

It was at 1750 hours on [[2525#November|November 27]] that the ''Commonwealth'' finally emerged in real space in the [[Chi Ceti system]].{{Ref/Reuse|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 him and John know that at Harvest the aliens had been observed making an intrasystem slipspace jump, something beyond the capability 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 recommendation. 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/Reuse|HTFOR12}}

{{Quote|Even though this technology will save humanity in [[Human-Covenant War|the war to come]], I must remind myself: liquid crystal cannot rise on its own. [[Titanium|Titanium]] alloy cannot prevail in the face of extinction. Armor cannot hope. It all means nothing until you step inside.|Halsey shares her thoughts with her Spartans.}}{{Ref/Reuse|BSI}}   

{{Expand-Section}}

[[File:HCD1 HalseyJohn.png|300px|right|thumb|Blue Team's actions on Alpha Corvi II were still not enough to endear Halsey's Spartans to the rest of the UNSC which knew about them, but they had more success in that regard [[Operation: SILENT STORM|a few months later]].{{Ref/Reuse|HCD3}}<ref name="HSS23">''[[Halo: Silent Storm]]'', ''Chapter 23''</ref>]]

===SILENT STORM===

{{Quote|no=four|q1=The UNSC has two choices at the moment, the one rotten and the other lousy. Either we engage the enemy right now and start losing fleets in battles we have no chance of winning, or we mass at strong points and let the enemy glass everything else.|Preston Cole|q2=I should think the answer is obvious. We mass at the strong points. It will take the Covenant ''at least'' two years to locate all of our undefended worlds, and by then the Materials Group will have reverse-engineered—|Catherine Halsey|q3=Catherine, FLEETCOM can't ''do'' that. We'd be leaving hundreds of worlds defenseless. We'd be condemning billions of colonists to death by plasma incineration.|Michael Stanforth|q4=And if you commit prematurely, you will lose every fleet you send—and leave hundreds of worlds defenseless anyway. I think you need to make FLEETCOM understand that, Admiral Stanforth. There is nothing you can do to save those people—not until I can give you the tools you need to fight.|Catherine Halsey|Doctor Halsey argues, unsuccessfully, for a strategy that would sacrifice billions but conserve military losses.}}{{Ref/Reuse|HSS4}}

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/Reuse|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/Reuse|HSS7}}<ref name="HSS8">''[[Halo: Silent Storm]]'', ''Chapter 8''</ref>

{{Quote|no=four|q1=Habitable worlds create gravity wells, and there aren't any—not within four days of the most likely transit nodes.|Catherine Halsey|q2=But there is a habitable world within five days of Transit Node Bhadra. Perhaps it's not my calculations that are mistaken, but ''your'' assumption.|Déjà|q3=Are you suggesting the Covenant has instantaneous interstellar communications?|Catherine Halsey|q4=I am suggesting the Covenant has a great deal of... technology that we don't... understand.|Déjà|Déjà brings Halsey to the right conclusion based on the evidence, despite being slowed by a data miner.}}{{Ref/Reuse|HSS20}}

At 0626 hours on [[2526#March|March 31]] Halsey was in the middle of studying the captured starholo.<ref name="HSS20">''[[Halo: Silent Storm]]'', ''Chapter 20''</ref> The ''Vanishing Point'' had relocated to the deep space Rendezvous Point Sierra-Yama within the [[Polona sector]]. With a little luck and lots of hard work, the doctor was hoping she could trace the Covenant's slipspace routes back to the [[Fleet of Inexorable Obedience|invasion fleet]]'s primary [[Zhoist|supply depot]]. By this point she had already identified more than twenty transit nodes which opened near what she believed were [[Etalan]], [[Harvest]], and [[Netherop]], and four of these were near other nodes which led out of human-controlled space. Five days had passed before a new supply convoy had arrived at Etalan following the previous one's destruction, so Halsey surmised its point of origin had to be somewhere between one-half and three-quarters of that distance at the aliens' slipspace travel rates. She asked [[Déjà]] how certain the A.I. was about the size of the logistics base that the Covenant fleet must require, but she only reconfirmed what had already been calculated previously. Catherine was flummoxed, since there simply weren't any habitable worlds within four days of the likely transit nodes. Déjà deigned to point out there was one within ''five'' days of [[Transit Node Bhadra]], however. Implicit in this observation was the idea that the Covenant must have instantaneous interstellar communications.{{Ref/Reuse|HSS20}}  

By this point Catherine had discovered a data miner had been slipped into her quarantined lab by [[Hector Nyeto]] or one of his operatives.{{Ref/Reuse|HSS20}} It was causing Déjà to make erratic pauses while speaking and had already stolen her most closely guarded data, but Halsey was tolerating it because she didn't want Nyeto to know she had noticed it yet. Nonetheless, the doctor agreed with what Déjà was suggesting and determined they ought to proceed to Transit Node Bhadra. With that settled the A.I. notified her Colonel Crowther had finally arrived. Catherine deactivated the starholo and ran her fingers through her hair briefly before meeting the colonel at her door. She'd sent him a message asking him to meet her there as soon as their rendezvous was complete for a "personal matter", and now that he'd shown up she feigned delight at his presence and took his arm to draw him toward her personal quarters. She confessed to being unable to wait any longer to be alone with him and made sure to press her flank against his as she pulled him through the other door into her little galley area. Once they were both sealed within, however, she released him and said she only needed to talk someplace safe. She let him know she swept for eavesdropping devices within her quarters three times daily and had found nothing so far. She offered the men water and apologized for leading him along before stating they needed to discuss how they were going to handle Nyeto before he tried to kill her Spartans again.{{Ref/Reuse|HSS20}}

Through researching Nyeto's records Catherine learned he had spent a lot of time with the infamous [[Robert Watts]] early in his career.<ref name="HSS21">''[[Halo: Silent Storm]]'', ''Chapter 21''</ref> She and Crowther told John that though they would leave him alone as the task force's commander for the time being, they planned on using him to mislead the enemy. Despite the improved slipspace efficiencies afforded by Doctor Halsey's understanding of the alien starholo, it still took the task force time to arrive at Transit Node Bhadra, more than two hundred light-years past humanity's farthest known exploration. It was Halsey who had named the transit node, and she likewise chose to call the [[sector]] of Covenant space they were invading by 0458 hours on April 14 [[Muruga sector|Muruga]], both [[Religion|Hindu]] names meant to honor Captain Ascot. Their target planet and its moon she called [[Naraka]] and [[Rudara]], respectively.{{Ref/Reuse|HSS21}} By April 15 Halsey had viewed reconnaissance videos which showed Naraka was encircled by a [[Ring of Mighty Abundance|ring]] of orbital support stations connected by a transit tube enclosed within what she called a trussing armature.<ref name="HSS25">''[[Halo: Silent Storm]]'', ''Chapter 25''</ref> In her estimation, if [[Sierra Force]] could destroy at least ten facilities and their connecting armature there was a ninety-two percent chance the ring's orbit would grow unstable and fall into a rapid, irreversible decay.{{Ref/Reuse|HSS25}} If only nine were destroyed, she predicted the odds of that happening dropped to seventy-one percent, and if only seven, forty-nine percent.<ref name="HSS27">''[[Halo: Silent Storm]]'', ''Chapter 27''</ref> Ultimately, [[Operation: SILENT STORM]] scored a giant win for the UNSC when the orbital ring was successfully brought down thanks to her Spartans and Crowther's ODSTs, but the colonel lost his life and Hector Nyeto fled from the rest of the task force during the mission.{{Ref/Reuse|HSS27}}

[[File:HalseyJournalNode.PNG|thumb|300px|right|Doctor Halsey considered the [[Wikipedia:Dendrite (mathematics)|dendritic]] growth of cross-connections in volitional A.I.s near the ends of their lives to be akin to the spread of [[Wikipedia:Cancer|cancer]] in biological organisms.{{Ref/Reuse|HJ5326}}]]

[[File:MJOLNIR.PNG|thumb|300px|right|By [[2535#January|January 7, 2535]] Halsey had turned over the fourteen existing variations of Mjolnir to Vice Admiral Stanforth at his request.{{Ref/Reuse|HJ1735}}]]  

At some point in the early [[2540]]s the [[Spartan]] [[Cal-141]] was killed during an engagement with the [[Covenant]] on the planet [[Heian]].{{Ref/Reuse|HLTB}} Before she died she entrusted [[Cortez|the]] [[ODST]]s of the [[105th Shock Troops Division]] who had accompanied her on [[Operation: GREY VEIL|the mission]] with all the data she'd gathered pertaining to [[Ancient humanity|unidentified alien]] ruins on the planet. Cal instructed them to see that it was delivered to Halsey, claiming the doctor would know what to do with it.<ref name="HLTB">''[[Halo Legends]]'', ''[[The Babysitter]]''</ref> On [[2543#March|March 18, 2543]] Catherine finally found her journal after having lost it for some time and was faced with the decision as to whether or not she should transcribe notes from a new journal she'd been using into it or even shuffle papers and rebind them.{{Ref/Reuse|HJ31843}} In any case, seeing as she couldn't always keep it on her, she recommitted to keeping it secure from low-tech prying. Writing in it on this date, she even mused over the possibility of implanting a small strip of [[nanocene]] explosive into the clasp and keying it to her DNA before admitting she'd likely employ a more refined method.<ref name="HJ31843">''[[Dr. Halsey's personal journal]]'', ''March 18, 2543''</ref> By March 21 an experiment which involved severing portions of an A.I. from its "living" matrix strata and then reintegrating data and connections had gone flawlessly.<ref name="HJ32143">''[[Dr. Halsey's personal journal]]'', ''March 21, 2543''</ref> Halsey was profoundly relived by the results because no literal "cutting" of the material had been involved and the reintegration of the separated A.I. portion with the mother A.I. strata represented a real innovation. [[Wikipedia:Optical communications repeater|Optical repeater]]s were maintaining the boundary value [[Wikipedia:Wave function|wave functions]] at zero within the original A.I., but it was recommended that the separation lasted no more than eight days. Her experiment demonstrated that excised parts of an A.I. could learn and evolve autonomously and still then be reabsorbed into the parent matrix. As this was only an experimental process, however, Catherine decided to designate it as "non-sanctioned" until she more carefully weighed its long-term ramifications.{{Ref/Reuse|HJ32143}} By [[2544#May|May 20, 2544]] Halsey had moved her laboratory a few times since she'd last written in [[Dr. Halsey's personal journal|her journal]] and had almost thought it lost in the process. On that date it was discovered that the [[Illegal Entry Protocols|illegal entry protocol]]s used for hacking [[Insurrectionist|insurgent]] networks had deciphered a tiny portion of the [[Kig-Yar point defense gauntlet|point defense gauntlet]] acquired over eight years prior.<ref name="HJ52044">''[[Dr. Halsey's personal journal]]'', ''May 20, 2544''</ref> In the journal Halsey then added them to a list of [[ONI Section Three|Section Three]] counter-insurgency strategies which had proved to be notable exceptions insofar as they had actually been effective against the Covenant. Following this she directed [[Jerrod]] to dedicate all his runtime to further avenues of inquiry. Even then, however, she was sure there was already enough data to run a simulated test for a [[Mjolnir]] [[energy shield]] system based on the [[Kig-Yar|Jackal]]'s gauntlet. It was her hope that greater understanding might lead to further insights into the [[Covenant]]'s [[Sangheili (language)|language]] and motivations. With so much going on and with so much to say, Halsey resolved to write more going forward.{{Ref/Reuse|HJ52044}}

[[File:HLTP HalseyChief.jpg|350px|thumb|right|Vice Admiral Tursk was unsure what Halsey had been doing on Miridem weeks into the [[Battle of Miridem|battle]] there, as ONI usually had a good eye on where she was at all times.{{Ref/Reuse|HTFORA}}]]

[[File:Halsey'sJournal Math.PNG|300px|thumb|right|Equations]]

On [[2547#September|September 3, 2547]] Halsey noted in her [[Dr. Halsey's personal journal|journal]] that following her inquiries regarding the assumptions of the [[Wikipedia:Tensor|mu-tensor]] calculation in Doctor [[Canterfeld]]'s latest paper in [[I.C. Physical Review]], Canterfeld had finally asked her for help with the areas of his research that were continuing to elude him.<ref name="HJ9347">''[[Dr. Halsey's personal journal]]'', ''September 3, 2547''</ref> He had responded to her inquiring by declaring that [[Slipspace|Shaw-Fujikawa space]] is "literally slippery" and then proceeding to explain why his assumptions were valid. Halsey was glad to help him, as she could see that his theories about slipstream anomalies could lead to a number of innovations, such as those which would result in faster ships and more accurate jumps. Catherine was convinced that [[humanity]] needed such advantages to counter the Covenant's superior technologies, noting at the same time that she was starting to doubt the idea that their enemy possessed superior intelligence. In addition to the benefits aiding Canterfeld could bring to the [[Human-Covenant War|war]] effort, Halsey also wondered if his contacts and support in the [[United Nations]] could effect a transfer for her. She chronicled her thoughts on the matter, questioning whether being permitted to devote herself to "pure" research would cause her to lose sight of how many were depending on her. She concluded, that with so many trails of her studies converging at that moment she could not leave, even if she did view her work as a sort of burden, [[Wikipedia:Purgatory|purgatory]], or [[Wikipedia:Dharma|dharma]], in spite of Admiral Stanforth's assertions regarding her "destiny". In the end, she wrote, it may be all that remains to her, having given up a normal life, [[Miranda Keyes|her family]], her [[Spartans]], and even the "illuminated entities" which she said she had come to understand. She was certain she wouldn't be able to make Canterfeld understand why she had to refuse him, so she decided to just send him a note the following day.{{Ref/Reuse|HJ9347}} That next day, the battle-worn [[UNSC Frigate|frigate]] {{UNSCShip|Tripping Light}} arrived in dry dock at [[Reach]], with its [[slipspace drive]] slated for disposal at 1615 hours.{{Ref/Reuse|HJ9447}} This was fortuitous to Doctor Halsey, who saw that drive as the last disparate component of several she had secretly acquired for an experimental procedure. One other of these was a [[Slipstream space probe|probe]] from [[Fermion|the planet]]'s [[Remote scanning outpost|early warning slipstream space observatory]]. In her journal Halsey mused over whether she possessed the mettle to steal the drive and conduct the experiment and couldn't help but think of fate and luck, despite her best efforts to reject entertaining such notions.{{Ref/Reuse|HJ9447}} She intended to build an abstract [[Wikipedia:Fractal|fractal]] structure within slipspace with an A.I. seed inside it.{{Ref/Reuse|HRTPDP}}

[[File:H5G Cortanabirthcropped.PNG|thumb|350px|right|Cortana's face resembles the way Doctor Halsey's appeared when she was fresh out of college.{{Ref/Reuse|HJ11749}} Part of her also resembles Halsey's daughter [[Miranda Keyes|Miranda]] and yet another part is purely Cortana's invention.{{Ref/Reuse|HJ11749}}]]

On [[2549#March|March 24, 2549]] Halsey made a note in which which she reminded herself to soon finish field tests experimenting with direct [[human]]-to-A.I. neural linkages.{{Ref/Reuse|HJ32449}} She believed such a linkage would serve as the final necessary upgrade incumbent to Mjolnir's [[MJOLNIR Powered Assault Armor/Mark V|Mark V]] platform, as well as the last gift she had to offer her Spartans.{{Ref/Reuse|HJ32449}} An exceptional A.I. was needed to assist them with [[Operation: RED FLAG]], a last-ditch effort to capture a Covenant [[hierarch]].{{Ref/Reuse|HTFOR25}}{{Ref/Reuse|WaypointCortana}} Though Halsey felt she had no other choice but to proceed in this direction, she did worry that in combining Spartans and A.I.s it felt as if she was losing both somehow.<ref name="HJ32449">''[[Dr. Halsey's personal journal]]'', ''March 24, 2549''</ref> On [[2549#May|May 21]] Doctor Halsey [[Flash cloning|cloned]] herself twenty times, thereby breaking civilian laws, [[UNSC Armed Forces|UNSC military]] regulations, and (far from the first time) the [[UN]] [[UN Colonial Mortal Dictata|Colonial Mortal Dictata]].{{Ref/Reuse|HTFOR25}}<ref name="HJ52149">''[[Dr. Halsey's personal journal]]'', ''May 21, 2549''</ref> She believed her third-generation "smart" A.I.s required better material to use as A.I. matrix seeds than that offered by the new candidates she was being presented with, which she saw as lacking both physical and intellectual agility. To create the clones she used the same equipment that had been used years prior to make the [[flash clone]]s needed for [[SPARTAN-II]]. This time, however, she enhanced their neural physiology at the expense of other biological functions. She made sure the equipment was hidden and secure from all save herself, though the cloning had been arranged by [[ONI]] at her insistence. As such, there were a few others who also knew about it, but she was confident that these particular individuals could be trusted to keep the information secret. The clones developed at a breakneck pace, for on the same day she had first begun the process they were already exhibiting familiar anatomy and curling into fetal positions, malformed as they were. In her journal Halsey noted how disquieting this was to watch, grieving for them and wishing she could allay their suffering somehow.{{Ref/Reuse|HJ52149}} A little over two months later, on [[2549#July|July 29]], Halsey successfully excised all of the clones' brains and transferred them to cryogenic units.<ref name="HJ72949">''[[Dr. Halsey's personal journal]]'', ''July 29, 2549''</ref> All remaining organic substrates were flash-incinerated. She planned at this time to complete her [[Mind transfer|personality transfer]] seven weeks later and was still uncertain whether or not she should tell them they were clones of her.{{Ref/Reuse|HJ72949}} It was at some point in [[2549]] that [[UNSC High Command]] finally made the Spartan-II project public in order to boost morale.{{Ref/Reuse|HTFOR25}} Halsey protested this at first, but ironically the publicity proved convenient because the attention on the Spartans' heroics distracted from questions about their origins.{{Ref/Reuse|HTFOR25}}

The first words spoken by Cortana were those Halsey's mother had said to her after beating her daughter in [[chess]] decades prior.{{Ref/Reuse|HJ11749}} Halsey recognized in the choice of phrase a confluence of morality, mortality, and metaphor. In her journal she recorded her delight and relief upon seeing that Cortana chose a simple human appearance for her avatar. She also mentioned that specimens H-2, H-3, and H-4 would remain in cryogenic suspension, as she had other plans for them which were dependent on evolving technology.{{Ref/Reuse|HJ11749}} On [[2550#February|February 11, 2550]] Catherine recorded a research excerpt in which she took note of certain metrics which implied the viral termination code in Cortana's matrix would have been unlikely to be successful and that the typical seven-year life cycle estimate may not apply to her.{{Ref/Reuse|H4RAL}} She'd determined that the unique circumstances of her creation had triggered what Halsey could only refer to as a "recessive variant" in the A.I. seed, but the doctor was at a loss concerning this rogue element's origin.<ref name="H4RAL">''[[Halo 4]]'', ''[[Requiem (level)|Requiem]]'' [[Halo 4 audio logs|audio logs]]</ref>

[[File:Babd catha forerunner complex.jpg|thumb|350px|right|[[Cortana]] spent the first few years of her existence assisting Doctor Halsey within the confines of [[CASTLE Base]], having been given total access to her work, but after the doctor began studying the mysterious ship buried in the ice shelf at Babd Catha she eventually began to use Cortana to retrieve navigation data from the ancient vessel.{{Ref/Reuse|WaypointCortana}}{{Ref/Reuse|HRO}}<ref name="HM89">''[[Halo Mythos]]'', ''page 89''</ref>]]

[[File:HReach - Carter and Halsey.png|375px|right|thumb|Doctor Halsey's first suspicion upon coming face-to-face with [[Spartan-III]]s was that they were substandard versions of [[Spartan-II]]s, perhaps from a parallel program like [[Project JAVELIN|Project: JAVELIN]] or some next-generation venture piggybacking on her work.{{Ref/Reuse|HJ72652}}]]

By July 23 contact with the relay hub had been lost.<ref name="HJ72352">''[[Dr. Halsey's personal journal]]'', ''July 23, 2552''</ref> Given how the communications network had been hardened years back and the urgency and demand for secrecy in Sorvad's message, Halsey ruled out a rudimentary malfunction, believing the loss to be more than a coincidence. She made a short list of possible explanations for the blackout, none of which were pleasant. She figured either internal subterfuge within ONI, [[Insurrectionist|insurgent]] action, or even the Covenant could be to blame. Halsey made sure Stanforth, who had personnel addressing the situation, was aware of her vital staff in the area. She also shared her thoughts on the potential causes with him and was told she'd be notified when her people were located.{{Ref/Reuse|HJ72352}} The next day she caught a rumor that a [[UNSC Special Forces|special forces]] unit had been sent to investigate the hub but that it too had disappeared.<ref name="HJ72452">''[[Dr. Halsey's personal journal]]'', ''July 24, 2552''</ref> Halsey learned that a second unit named "[[NOBLE Team]]" would be sent to investigate next, but she could not get anyone to give her any further details. Without even knowing what branch of the [[UNSC Armed Forces|armed forces]] this NOBLE Team belonged to, she resolved in her journal to follow up on it as soon as possible. Meanwhile, the doctor was also receiving scattered data from the usual suspects concerning atmospheric anomalies along with radar and slipspace monitoring glitches. She compared these events to those recorded near [[Sigma Octanus IV]] but there were no matches.{{Ref/Reuse|HJ72452}}

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 [[Catherine-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 (protocol)|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/Reuse|HROSB}}

[[File:Reach HALSEY.PNG|thumb|300px|right|While reviewing the Spartans of NOBLE Team with Cortana, Halsey noted that only Spartan-B312 and one other Spartan then had the rating of "hyper lethal".{{Ref/Reuse|ASWR}}]]

[[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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|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/Reuse|HRTP}}{{Ref/Reuse|ASWR}}{{Ref/Reuse|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/Reuse|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/Reuse|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/Reuse|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>  

[[File:HFORI HalseyChip.PNG|thumb|200px|right|Halsey presents Cortana to John.]]

[[File:HR HalseyJun.png|thumb|right|300px|After delivering the doctor to CASTLE Base Jun headed elsewhere, somehow making it off Reach alive.]]

[[File:Halsey Mem.jpg|250px|right|thumb|Dr. Halsey's ONI memorial plaque.]]

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

[[File:Halsey Infinity.png|right|thumb|300px|Halsey examines the recovered Forerunner artifact.]]

In mid-[[2558#February|February 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/Reuse|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/Reuse|H4SOC}}{{Ref/Reuse|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/Reuse|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>

[[File:H4-SOps-Halsey-Librarian-1.jpg|thumb|250px|Dr. Halsey meets the [[Librarian]], and learns of the Forerunner artifacts all over the galaxy.]]

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/Reuse|HE13}}

[[File:HE16 Next destination The Absolute Record.jpg|thumb|220px|[[Jul 'Mdama's Covenant|“Covenant”]] [[Supreme Leader|supreme leader]] Jul 'Mdama and Doctor Catherine Halsey collaborate to find the Absolute Record.]]

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>

[[File:Halsey.PNG|thumb|right|300px|By the time of his death, Jul 'Mdama had begun to think having Halsey around was more trouble than it was worth.{{Ref/Reuse|H5GOMI}}]]

[[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 [[Catherine-B320|theories]] that [[human]] females signal maturity by losing appendages.{{Ref/Reuse|H5GBTSMI}} He further hypothesized that she would soon begin to release spores and spin a cocoon of "rich meat-silk".{{Ref/Reuse|H5GBTSMI}}]]

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/Reuse|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/Reuse|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/Reuse|H5GBOS}}

[[File:LC 12 doc4.jpg|thumb|350px|right|This image was captured by Spartan [[92738-61842-LC]], who wore their helmet while interviewing Halsey in order to record the interaction.{{Ref/Reuse|lootcrate12}}]]

By [[2559#January|January 24, 2559]], they were still on the run, performing erratic jumps to evade discovery.{{Ref/Reuse|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/Reuse|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/Reuse|lootcrate12}}{{Ref/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.}} On [[2559#September|September 19, 2559]] 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="BSI">''Halo Infinite'', [[Step Inside]]</ref><ref name="DH">''[[Discover Hope]]''</ref>{{Ref/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/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.}}

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

An ONI-commissioned [[Hemley & Aubourn Behavior Analysis|psychological evaluation]] conducted by [[B.M. Parkes]] in [[2551]] largely correlated with observed aspects of Halsey's personality, demonstrating exceedingly high cognitive performance (which was noted to possibly obfuscate the rest of the results) but a markedly low score in teamwork and an uncommonly high "liability" index, 64% higher than the average ONI rating due to her demonstrated disregard for authority. The analysts suggested that she be placed under closer surveillance, with two or three handlers accompanying her at all times at both of her primary working sites on Reach.{{Ref/Reuse|DD3}} Halsey designed the most recent model of AI matrix compiler used in the [[Cognitive Impression Modeling|scanning of human brains]] to create smart AIs. This particular compiler was still in use by [[2557]].<ref name="Composer logs">'''Halo 4''', campaign level ''[[Composer (level)|Composer]]'', [[Halo 4 audio logs|Audio log]]</ref>

[[File:Halsey Eyes.png|thumb|right|300px|Halsey battled guilt over the SPARTAN-II project. She knew that moral lines had been crossed to save humanity.]]

[[File:FoR - Ackerson n Halsey.png|right|thumb|250px|Halsey and her rival, Colonel James Ackerson.]]

Halsey's projects and the results they yielded gained her widespread acclaim and sympathies among many high-ranking members of the UNSC military, such as [[Admiral]] [[Michael Stanforth|Stanforth]], her most powerful ally within ONI, and [[Fleet Admiral]] [[Terrence Hood|Hood]], who deeply respected Halsey and her Spartans who had saved his own life twice, to the extent that he verbally rebuked Colonel Ackerson for detracting the Spartan-IIs.<ref name="hood">'''Halo: First Strike''', ''page 104'' (2003)</ref> However, she also garnered a number of competitors and opponents over the decades. The most notable of her rivals was [[Colonel]] [[James Ackerson|Ackerson]], who constantly tried to spy on her and co-opted her work while attempting to sabotage the SPARTAN-II program. Her former student [[Ellen Anders]] also resented Halsey, saying "She hated me and I hated her."<ref>'''[[Halo Wars]]''' ''manual, character profiles''</ref> ONI Commander-in-Chief, [[Admiral]] [[Margaret Parangosky]], was resentful of Halsey, perceiving the doctor's aversion for control and her general lack of loyalty to ONI as a threat. The Admiral only tolerated Halsey because she was so crucial to the war effort,<ref>'''Halo: Ghosts of Onyx''', ''page 48''</ref> but had her detained immediately after the end of the war. Parangosky's antipathy for Halsey was passed on to [[Serin Osman]], a Spartan-II washout whom the Admiral specifically indoctrinated and groomed to become her successor to secure her personal legacy within ONI, and ultimately culminated in Osman ordering Halsey's assassination after the Covenant abducted the doctor during the [[Second Battle of Requiem]]. Parangosky's, and later Osman's, AI attaché [[Black-Box]] also had an intense dislike of Halsey. This was, at least partly, passed on from his brain donor, [[Graham Alban|Dr. Graham Alban]], who worked with Halsey on the SPARTAN-II program and eventually committed suicide over his guilt. Both Alban and BB doubted the sincerity of Halsey's doubts about the ethics of her work and viewed her as genuinely amoral.<ref>'''Halo: Mortal Dictata''', ''pages 490-492''</ref>

[[File:Halseykeyes.png|250px|thumb|right|Jacob Keyes accompanies Dr. Halsey.]]

[[File:Halo TFoR HalseyJohnhelmet.jpg|right|thumb|300px|John, at 14 years of age, having his original Mjolnir helmet put on by Dr. Halsey.]]

*In ''[[Halo: Reach]]'', ''[[Halo 4]]'', and ''[[Halo 5: Guardians]]'', Dr. Halsey is voiced by [[Jen Taylor]], who also voices Cortana, reinforcing the connection between the two characters. This is mirrored in ''Halo Legends'' (which predates the three games), in which [[Shelley Calene-Black]] voices both Halsey and Cortana.<ref>'''''Halo: Legends''''' credits</ref> [https://www.imdb.com/name/nm0001523/?ref_=ttfc_fc_cl_t2 Natascha McElhone] will play Halsey in ''[[Halo: The Television Series]]'' as well as Cortana.

**''[[Halo 5: Guardians Limited Edition|Limited Edition]]'' {{Mo}}

*''[[Step Inside]]''