Sarah Palmer

"Some of the old hands here know what you're in for. The rest of you: you're due an education."

- Palmer to the SPARTAN-IV initiates

Commander Sarah Palmer is a human senior officer of the Spartans serving in the post-war years. She was augmented as part of the SPARTAN-IV Program, and currently serves aboard the as the commander of the Spartan contingent. Palmer wears the Scout variant of the MJOLNIR GEN2 armor, in-lieu of specialized communications models built specifically for Spartan officers.

Early life and career
Sarah Palmer was born to parents living in colonial planets who disliked the UNSC. She did not agree with her parents and would later join the Marines. She served twelve tours on eight worlds as a lieutenant. Palmer was considered a great choice by ONI due to her physical prowess and innate leadership. She became one of the first recruits of the Spartan-IV Program.

Arrival on Requiem
At some point after the Human-Covenant war, Palmer was enlisted in the SPARTAN-IV Program. Palmer was assigned to the, whose mission was to locate the remaining Halo rings to set up research bases for decommissioning. On Installation 03, a science team was vaporized by a Forerunner artifact that Infinity extracted from the ring. Coordinates from the artifact eventually led Infinity to a Shield World called Requiem, where it was scanned and pulled into the planet. Though Infinity made a safe, if rough landing, the ship came under attack by Covenant Remnant and Prometheans, led by a surviving Forerunner known as the Didact. Palmer, along with XO Commander Thomas Lasky were sent out by Captain Andrew Del Rio to conduct recon, believing that Infinity could hold off the attack and provide cover simultaneously. They were rescued by Master Chief John-117, the legendary Spartan-II long thought dead. Upon meeting, Palmer commented that she'd thought he'd be taller.

Once the attack was repelled, Palmer arrived on the bridge as Del Rio and Lasky were debriefing the Chief on Infinity's mission. Palmer informed Del Rio that Gypsy Company was ready to assault the gravity well keeping Infinity from escaping. Though the Chief insisted they pursue the Didact, Del Rio refused, concerned with getting Infinity out of Requiem.

After the successful destruction of the gravity well, Palmer was once again present on the bridge, as the Chief informed Del Rio of his encounter with the Librarian, who warned him that the Didact intends to escape Requiem to seek out the Forerunner device known as the Composer to turn all of humanity into Prometheans. A skeptical Del Rio dismissed the Chief's testimony as a hallucination and ordered Infinity to prepare for departure. Then suddenly, the Chief's AI, Cortana, suffered an episode of rampancy. Perceiving her as a threat to his ship, Del Rio ordered Lasky to take her AI chip for decommissioning. However, the Chief snatched it before he could. Del Rio demanded that the Spartan hand over Cortana, to which the latter defiantly refused. This incensed Del Rio, who ordered Palmer to arrest the Chief but she hesitated, as the Spartan-II departed the bridge.

After the Didact's defeat, Palmer was present on Infinity's Spartan deck as the Chief marched by to have his MJOLNIR armor removed.

Spartan Ops
After Captain Del Rio had been removed from command of the UNSC Infinity, Commander Palmer effectively became second-in-command behind Captain Lasky. Lasky may have chosen her himself due to her leadership and military knowledge, as well as her being the overall Commander of the SPARTAN-IV Program aboard the Infinity.

Six months after the Didact's attack on New Phoenix, Infinity was to return to Requiem to clear out the Covenant Remnant and Prometheans and set up research bases. Palmer personally greeted Fireteam Majestic upon their arrival. The team leader, Paul DeMarco, attempted to make a pass at her, unaware of her identity before she announced it. DeMarco quickly fell back in line and ordered his team to salute the superior officer.

After showing Majestic around, Palmer joined Lasky on the bridge to discuss the battle plan. She shares many of Lasky's ideas and goals, however she often believes her way may be best. This was seen when she openly questioned Lasky's order for the SPARTAN-IV's to be made ready immediately, whereas Palmer wanted them to spend more time in the War Games but was over-ruled. Soon after she rallied the SPARTAN-IV's and warned them of the dangers of Requiem just as the UNSC Infinity exited slipspace, sparking the Second Battle for Requiem between the UNSC, Covenant Remnant and Prometheans.

When Majestic returned after escaping a Promethean ambush, Palmer met the Fireteam as they disembarked. She asked DeMarco what happened to his teammate, Hoya, who was lying wounded on a stretcher. After DeMarco's brusque response, she ordered him to the armour bay, annoyed.

Nearby, a Forerunner artifact retrieved by Fireteam Crimson was being brought on board. The scientists barely got it a few meters off the Pelican before it spontaneously activated, causing disruption of the ship's systems, loss of artificial gravity and power to the engines. Palmer clung to the deck with magnetic boots and marched up to give a swift kick to the device, deactivating it and restoring Infinity's systems to normal. The artifact then became stuck to the floor, refusing to react from any further attempts of "physical persuasion". Dr. Henry Glassman attempted to inspect the artifact, only to be accidentally teleported to Requiem by it.

Lasky needed expert help in determining what the artifact was and summoned Doctor Catherine Elizabeth Halsey to Infinity. Palmer showed outright hostility towards the war criminal, reminding Lasky she was locked up for a reason. Halsey determined that the artifact was communing with Infinity's engines, the only Forerunner tech installed on the ship, several Human systems and something on Requiem.

Sometime later, Palmer informed Lasky that Fireteam Castle getting shot down on a supply run. The area they were in was the same place where Master Chief encountered the Librarian AI. Unfortunately, the place was occupied by the Covenant Remnant leader, Jul 'Mdama.

Majestic was later dispatched to Requiem to retrieve a package. Upon bringing it to Halsey, she determined it to be similar to an AI matrix. Palmer and Majestic were observing the dissection before the device let out a flash of light and projected images of New Phoenix on the lab monitors. Halsey determined that this was from a Promethean's memories. This caused Palmer and Lasky to exchange worried looks. Halsey took notice and confronted Lasky, who confesses that the UNSC has been aware that the Prometheans were created from ancient Humans. She pointed out that this Promethean was once a human who lived in New Phoenix. As Lasky expressed confusion as to how these memories got to Requiem, Gabriel Thorne abruptly left the room. Halsey realized he was staring at an image of the artifact. Palmer and Lasky escorted her back to it. Palmer mocked Halsey for not having the answer to everything. Halsey retorted that she was excluded from information.

Palmer then became suspicious when she heard Halsey mutter the Librarian's name. She snatched the doctor's datapad and discovered a secret communique with an unknown individual, which she passed to Lasky.

Lasky then ordered Palmer to take Halsey into custody for withholding vital information. As they took her to Lasky's ready room, Halsey negatively compared the UNSC to children in a sandbox. Palmer coldly reminded her that the Office of Naval Intelligence would put her in something much smaller than a sandbox. The scientist defended that she didn't share information with her contact, whom she believed would benefit humanity and criticized Palmer for being too trigger-happy. Just then, Roland reported that Thorne had been detected alive on Requiem.

Sometime afterwards, Promethean Knights started manifesting through the artifact. As her guards were slaughtered one-by-one, Palmer was soon left to singlehandedly hold off the Prometheans in the hangar as they began to spread throughout the ship. Palmer soon rendezvoused with Lasky and Halsey as they made their way to the bridge. Lasky ordered Infinity to move away from Requiem, but Roland informed him that the artifact is acting as a slipspace anchor locking them in place. Palmer expressed confusion, as slipspace isn't physical. Halsey remarked that there's still much they don't know about it. Palmer cut her off, criticizing her for failing to fix this. Then suddenly, a Promethean materialized on the bridge, knocking Palmer down and grabbed Halsey before disappearing. Getting back up, Palmer realized that the Prometheans came for her and slammed her fist on the star map, creating a dent in it.

Admiral Serin Osman of ONI ordered Halsey's termination for consorting with the enemy, a task that Palmer agreed to undertake. Lasky protested the decision, wanting to spare Halsey, but Palmer stated that she's doing this so that Lasky won't suffer a court martial. Palmer journeyed to Requiem, stealthily killing a Covenant patrol with just a combat knife. But as she entered the Librarian's shrine, she found Fireteam Majestic having joined the fight and Halsey in Jul's clutches. Palmer managed to shoot Halsey in the shoulder as Jul summoned Promethean Knights to protect him before teleporting away with Halsey. Angry that they got away, Palmer turned to Majestic, demanding to know why they are here. They answer that Lasky ordered them to rescue Halsey but Palmer retorted that she's a traitor. However, Thorne insisted that she wasn't, as he shows her a piece of the Janus Key Halsey passed to him, a gift from the Librarian herself.

Halsey being in enemy hands was the least of their problems, for Jul had set Requiem to collide with the sun, and take Infinity with it. Dr. Glassman, who was rescued by Majestic, determined that there are two artifacts on the planet that, if deactivated, would free Infinity. Palmer worked with Majestic to take out one artifact while Crimson went after the other. Once their mission was complete, both Fireteams quickly made for Infinity and the supercarrier barely made it to slipspace as Requiem's collision caused the sun to go supernova.

As the crew rejoiced, Palmer later criticized Lasky for trying to thwart her. The Captain defended that he sent Majestic to rescue Halsey, not stop her, but she failed to see the difference. They then enter the lab where Glassman was examining the Janus Key. He determined that without the other half, it's currently useless.

Trivia

 * Palmer is voiced by actress Jennifer Hale, popularly known as the female voice for Commander Shepard in the Mass Effect trilogy and Bastila Shan, Satele Shan, and the female voice of the Republic Trooper in the Star Wars: Knights of the Republic series.
 * Her facial appearance is based on actress Vedette Lim.
 * She is never seen with, or wearing, a helmet before Episode 9.
 * She however has been seen wearing her Scout helmet in a Work In Progress in-game model and, later, on her Square Enix's Play Arts Kai figure.
 * She wears her helmet on the Episode 9 of the Spartan Ops, in order to assassinate Halsey
 * During Infinity, Palmer says "I'd thought you'd be taller" to John. This could be a reference to the Halo PC map Infinity's description, "I imagined it would be bigger."
 * Contrary to what she says, Master Chief is at least 5 inches taller than her when suited up (it's mainly seen during the Epilogue of Halo 4). However, her statement might just have been sarcastic, or she might have been excpecting 117 to be much taller than her.
 * She is the first SPARTAN-IV to be seen dual-wielding.
 * Her helmet appears to be fitted with the "Pioneer class" visor.

List of appearances

 * Halo 4