Catherine Halsey

Catherine Elizabeth Halsey, M.D., Ph.D., was a brilliant Scientist and employee of ONI, best known for her work with the Spartan-II Super-soldier and MJOLNIR Armor programs. Despite being a civilian, she held considerable authority within ONI and commanded considerable respect from many military figures. Publicly, she was well regarded, in particular because of her evident compassion for and guilt about the Spartan-IIs.

Early Life
Not much is known about Dr. Halsey's early life, but what little is known gives a glimpse of what would be a promising career. By the age of 15, Dr. Halsey was already writing her second Doctoral Thesis paper. It is also known that at some time in her early life, she supervised the creation of the template for third-generation Smart AIs.

ONI Projects
Dr. Halsey made huge contributions to many ONI Section III projects including the creation and deployment of Artificial Intelligence constructs (such as Cortana). She also created the Spartan-II project and initiated the development of the MJOLNIR Armor Systems.

The SPARTAN-II Project
Dr. Halsey was the one who came up with the idea of the Spartan-II project. She built a set of rigorous genetic requirements that any potential candidate of the program had to meet. From these requirements, she identified 150 candidates, but ONI would only give her funding to train 75 of them. Along with Lieutenant, Junior Grade |Jacob Keyes, she met and interviewed each of the candidates and determined who the 75 would be. She then secretly brought the future SPARTAN-II's to Reach.

With the assistance of Chief Petty Officer Mendez and the AI Deja, she proceeded to train the Spartans. She supervised their augmentation procedures, combat training, and education, and studied the effects of the Spartan lifestyle on the children. She kept in close contact with them all throughout their lifetimes from her base under Reach. Annoyingly to the Spartans, she was always able to tell them apart from each other, even under half a ton of MJOLNIR battle armor. Dr. Halsey always used their first names, never their ranks or Spartan ID numbers.

Spartan Rescue
In 2552, the Covenant attacked Reach. Dr. Halsey was working in CASTLE Base at the time and volunteered to remain behind to ensure that all UNSC technology was secured from possible capture. With expectations that the Covenant would glass the planet and knowledge that even if they didn't glass it, she would be facing an entire army of Covenant ground forces, it was clearly an offer of sacrifice.

However, this changed with Spartans Fred-104, Kelly-087, Vinh-030, Isaac-039, and Will-043 appeared at the entrance to CASTLE base. With the firepower to possibly fight their way out, the possibility of surviving CASTLE base's destruction became available. She did what she could for their injuries, but a data anomaly detected by her accompanying AI, Kalmiya, attracted Dr. Halsey's attention.

Ackerson
The data had been accessed by Araqiel, an AI that worked for Colonel Ackerson, one of Dr. Halsey's main competitors within ONI. After tracing the data access, Dr. Halsey stumbled across the AI, left behind by its master. After shutting it down, she proceeded to read through Ackerson's files and discovered a number of things including the location of Onyx, evidence of the Spartan III program and a map of the mining tunnels CASTLE base had been built upon. The latter particularly interested the Doctor as the file had been classified at X-Ray level, making the file abnormally important for ancient maps. From this, she deduced that there was something of importance under the mountain.

Deducing that, at the very least, these maps provided a back door, she chose to move the Spartans out of the base and into the mine shafts. She triggered CASTLE base's self-destruct mechanism and activated the failsafe on Kalmiya. With the Spartans in tow, they moved into the mine shafts and found themselves in a Forerunner base.

The Crystal
Over the course of the next five days, the Spartans and Dr Halsey searched the base, looking for either an exit or what Dr Halsey would dub "The most important discovery of the millenium." On the fifth day, Fred discovered an entrance into the main section of the base where they found a Forerunner Crystal. However, the acquiring of the crystal sent a spike of neutrino radiation, attracting the attention of the Covenant.

Halsey and her team retreated into a hallway and sealed off the entrance, losing Vinh and Issac in the process. However, the quickly discovered that the hallway was a dead end.

Rescue
Several weeks later, a group of Spartans lead by John-117 rescued her and evacuated them from Reach.

Escape into the Unknown
Dr. Halsey later saw the importance of destroying this artifact, for it was too dangerous and uncontrollable to use. After escaping Reach, she stole a small spacecraft and, along with sedated Kelly-087, escaped into Slipspace. She entrusted the Forerunner Crystal to Corporal Locklear, telling him that if ONI obtained it, it could fall into the hands of the Covenant. Her whereabouts were unknown until the events of Ghosts of Onyx.

The Good Doctor Returns
In Ghosts of Onyx, Dr. Halsey and Kelly eventually make it to Onyx, while reuniting with SCPO Mendez and eventually her remaining SPARTAN-II's and the SPARTAN-III's. She helps decipher the mystery of the planet. At first, she tried to maintain secrecy about her intentions out of habit, until Kurt-051 confronted her about it. She admitted that she was not actually looking for weapons, but rather the secret Forerunner Shield World which she believed to be equivalent to a "bomb shelter." Her relative expertise with Forerunner technology was vital to the survival of the UNSC forces on Onyx. At the end of the Battle of Onyx, She, along with Mendez, Blue Team, and the Spartan-III survivors, found herself inside the Shield World, which she believed was actually a Micro Dyson Sphere.

Halsey's Guilt
Dr. Halsey carried extraordinary guilt because of the SPARTAN-II project, and she felt that she had exploited the children and destroyed their lives. Though she continued to support them and gain monumental prestige for her efforts, she also felt responsible for each one who died. She never could quite justify their exploitation as a "necessary sacrifice". This likely accounts for her actions in abducting Spartan-087.

Skills and accomplishments
Dr. Halsey has made numerous accomplishments over the years. Aside from being the Mastermind behind both the Spartan-II and MJOLNIR projects, she also supervised the creation of the third-generation Smart-AI template. She demonstrates extensive skills in hacking and decryption and is a mathematical genius.

Her experience and time with the Spartan-IIs give her the insight to be able to identify each Spartan even when they are wearing their MJOLNIR armor. She also attempts (and regularly succeeds) at portraying herself as omnipotent, particularly amongst the Spartans.

Appearances

 * Halo: The Fall of Reach
 * Halo: The Flood (mentioned)
 * Halo: First Strike
 * Halo: Ghosts of Onyx