Halo TL;DR #1 – Catherine Elizabeth Halsey

Today, we are kicking off a brand new series of posts here on Ready Up Live! There are many of us who are avid Halo fans, but don’t know as much about the lore as we would like. Whether you’re  new to the franchise or a veteran, there is always something you don’t know. People tend to know “a bit,” but haven’t read a certain book or played a certain game, and miss out on huge events in the story universe. This new series will aim to detail every event that involves the chosen topic.

We will be covering a wide variety of elements from the Halo universe, including locations, characters, weapons, events, and more! To kick off RUL’s “Halo – Too Long; Didn’t Read”, we’re taking a look at the infamous Dr. Catherine Elizabeth Halsey…


Heralded by some as an unsung hero, and condemned by others as a super-villain – Halsey is arguably the most complex and mysterious character in the Halo universe.

Earmarked as a prodigy early on, having written her second doctoral thesis at the age of 15, it’s a no-brainer that ONI took a great interest in her. In 2517, Halsey began the SPARTAN-II and Mjolnir Armour projects to aid the UNSC in its war against the outer colony insurrectionists. In order to create the SPARTAN super-soldiers, she had to kidnap and train a select group of 75 children, before subjecting them to an intense series of augmentations.

As you would expect from experimental augmentations, such as bone strengthening and muscle enhancements, there were very high failure rates. Rather than the expected 12.5% fatality/deformation rate, with expected side effects like blindness, Parkinson’s Disease and mutation, a massive 30 of the 75 Spartans were killed in the process and a further 12 were deformed beyond the point where they could engage in active military service. Whilst Halsey called this an overall failure, the remaining Spartans emerged better than ever – resulting in successes like the Master Chief, who went on to save humanity as a species. The big question has always been whether the ends justify the means.

After working with the Spartans, Halsey worked on a series of AI experiments, which resulted in Cortana. Cortana was created from a clone of Halsey’s brain, and was created as a key element of Operation: RED FLAG – the UNSC’s plan to end the war by kidnapping a Prophet. This plan was cut short when Reach was attacked. Halsey split Cortana into two fragments, one to assist the Spartans with RED FLAG, and the other half to decipher the data found in the Forerunner ship under Sword Base. Halsey’s final involvement with Cortana was to entrust Noble Six with that fragment of Cortana, instructing him to reunite the fragment with the rest of Cortana on the UNSC Pillar of Autumn.


Halsey escaped the attack on Sword Base with the help of Jun-A266, and was taken to CASTLE Base where she initiated Operation: WHITE GLOVE – purging the facility of all research. Shortly after John-117 and his team transported Halsey off of Reach, she “kidnapped” Kelly-087, and left for Onyx using coordinates found in CASTLE Base. On arrival, Halsey and the Spartan-III’s under attack there fled into the Shield World element of Onyx – a Micro Dyson Sphere. After several days exploring the location, they were able to establish contact with ONI and Halsey was arrested for Kelly’s kidnap, among other crimes.

Shortly after, Halsey was set to work on the UNSC Infinity. She was then transported to Ivanoff Station for some years, assisting in the research on discoveries made on Installation 03.


After Master Chief defeated the Didact, research was focused on the Forerunner technology and facilities on Requiem. Whilst Halsey was analyzing the artifact retrieved by Fireteam Crimson, she was also in contact with Storm leader Jul ‘Mdama. Halsey was taken by the Prometheans and delivered to ‘Mdama, who put her to work on activating an artifact that held the Librarian.

Eventually, she was able to activate it, and she ran inside it, coming face-to-face with the Librarian. She was given the Janus Key, a two part device that shows the location of all Forerunner technology in the galaxy. When she left the Librarian, she threw one half of the key to Spartan Thorne, and Halsey was then grabbed by ‘Mdama, along with the other half of the key. She was shot in the arm by Commander Palmer. Halsey’s arm was amputated due to her injuries. Last we saw her, she was on a ship with Jul, talking of wanting revenge.


STILL tl;dr

Catherine Halsey was an unethical genius who designed the most badass super-soldiers the universe has ever seen, created the most attractive AI to date and lost an arm because Palmer is a terrible shot.

Chewy TL;DR

LOL! Halsey has one arm!

Have any questions about Halsey? Have you got a request for our next Halo tl;dr? Let us know in the comments!