Olivia-G291

Olivia-G291, nicknamed "O" or  ' Livi is a SPARTAN-III supersoldier of Gamma Company. Originally assigned to Team Saber, one of the leading squads in Gamma Company, she served as part of Blue Team following the Battle of Onyx.

Conscription
Olivia joined the SPARTAN-III program developed by Colonel James Ackerson around 2546 between the ages of five and seven when she, along with other orphans, volunteered to become Spartans and avenge their families' deaths. She and the other Spartan-III candidates were trained under Senior Chief Petty Officer Mendez, surviving Beta Company SPARTAN-IIIs Lucy-B091 and Tom-B292, and SPARTAN-II Lieutenant Commander Kurt Ambrose on the planet Onyx.

Initial attack
Olivia was assigned to Team Saber under the command of Ash-G099. When the human forces on Onyx came under attack by Sentinels on October 31, 2552, the teams were still vying for top honors. Team Saber went dangerously close to the restricted Zone 67 to avoid the other teams during a training exercise. There they spied what they assumed at the time to be a new kind of Covenant drone, based on its energy shielding, and decided to investigate. The Sentinels quickly turned hostile, forcing the exercise to come to an abrupt halt.

Olivia remained with the team as they tried to figure out the drones' weak spots. She and the rest of the team hurled rocks at the drones and to their surprise, the drone's shields did not activate. One of the Sentinels chased Ash into a small ravine, but he was saved by the rest of the team, who pummeled the Sentinel with rocks, destroying it just in time.

Regrouping with UNSC forces
A general decision was made and the Team moved to the Camp Currahee armory to obtain heavier weapons. Team Saber met up with Commander Ambrose, CPO Mendez, Tom, and Lucy, and proceeded to engage the Sentinels with guerrilla tactics. Some time later, Olivia and the team met up with Kelly-087 and Dr. Catherine Halsey but had no time for pleasantries because they were soon engaged by a pair of Sentinels. After the skirmish was over, the team took Dr. Halsey and Kelly to a bombed-out bunker, while Olivia went out on watch. While in the bunker, Dr. Halsey revealed the origin of the Sentinels and what their next action should be.

Just as Team Saber was in the middle of battling the Sentinels, a Covenant dropship from the Bloodied Spirit, carrying SPARTAN-II Blue Team—Fred-104, Linda-058, and William-043—landed rather abruptly in the forest at the source of an emergency transmission sent out by the UNSC forces on Onyx. With the Sentinels increasing in number, Olivia and the others decided to retreat back to Zone 67. By now, the team had figured out that the Sentinels only come after them in pairs and there was always one observer that recorded all of the action and reported back to others, making the Sentinels smarter and harder to defeat each time they engaged in combat with the humans. Using Kelly as bait, they managed to trap a Sentinel pair in a tunnel, thereby buying themselves some time.

Retreat into Zone 67
Shortly thereafter, they moved into Zone 67 and discovered an unearthed Forerunner city. Once there, they discovered the map room of Onyx and the location of Team Katana, whose signal Olivia had picked up earlier before communications with them were lost. Meanwhile, a Covenant fleet led by Fleet Master Voro Nar 'Mantakree arrived at Onyx, dispatching forces after the Spartans. In looking in the map room and examining the Forerunner text, Dr. Halsey figured out how to utilize Onyx's slipspace translocation grid, allowing them to easily move across the artificial world.

Just before the team was about to jump to team Katana, Zone 67's AI Endless Summer contacted Dr. Halsey and Kurt-051, telling them they needed to destroy the Sentinel manufacturing facility in order to save a UNSC battle group in orbit. After teleporting to the Sentinel factory near the northern pole of Onyx, Olivia and Team Saber used the facility's teleportation grid to an advantage, destroying three key structures by tricking Sentinels into firing on them in a line with the structures. Having successfully destabilized the factory's systems, they teleported away as the facility was destroyed.

End of the battle
Olivia and the rest of the team translocated at Team Katana's holding area to find them in slipspace field pods. By deciphering Forerunner glyphs, Dr. Halsey found out that there was a shelter known as a "shield world" in Onyx's core, and persuaded Kurt and the others to make their way to it. However, the Covenant knew the location of the group and was on the way with an entire armada of troops to attempt to stop them.

After making their way into the core room of Onyx, Olivia, along with the other Spartans, made a loose half-circle kill zone around the entrance to the shield world and picked off targets at range. They managed to defend the slipspace rift, although it had come at some serious losses; Will, Dante, and Holly had already died at the hands of the Covenant. As there was little time left and the Covenant forces were closing in for the final kill, Kurt ordered Olivia and the rest of Team Saber through the portal, while he stayed behind to detonate two FENRIS nuclear warheads and deny the Covenant access to the shield world.

Shield world
On the other side of the slipspace rift, Olivia and the others found themselves inside a Dyson sphere habitat. There, Olivia and the other survivors waited for Kurt to arrive, but he never came. Shortly afterward, they made gravestones for William, Dante, Kurt and Holly; Olivia was then accepted into Blue Team, along with Ash and Mark.

Olivia and the other survivors then proceeded to explore the sphere in order to fulfill their mission to find valuable Forerunner technologies and take them back to Earth. After they had reconnoitered the vast construct for some time and established a camp in a Forerunner structure, Lucy-B091 discovered several Huragok which helped the human survivors contact the ONI ships outside and eventually disabled the slipspace bubble, bringing the shield world into normal space. As the sphere had occupied a pocket of alternate space-time, Olivia and the others had only experienced the passage of several days, whereas over three months had passed in normal space-time. After being retrieved by Kilo-Five, Olivia and the others were taken to Earth aboard the for a debriefing in HIGHCOM Facility Bravo-6.

Gao and later career
Olivia and the other Spartan-III survivors of the Battle of Onyx continued to serve with Blue Team, and in May 2553 they were deployed to escort a UNSC research battalion sent to recover a Forerunner ancilla on the human colony of Gao. In early July, they became mired in a major crisis after several Gao inhabitants were found murdered in the Montero Cave System. Veta Lopis, a Special Inspector of the Gao Ministry of Protection initially suspected the Spartans to be responsible for the murders, but the killer turned out to be the Forerunner AI the UNSC had been looking for, Intrepid Eye.

After the events at Gao, Admiral Margaret Parangosky decided to have Olivia, Mark, and Ash reassigned to a classified infiltrator unit nicknamed Ferrets, led by now-ONI agent Veta Lopis. To prevent knowledge of the dangers of their enhancement, Parangosky decided to publicly list Olivia, Ash and Mark as KIA, with Fred-104 personally deciding their false fates. By September 2553, Olivia and the other members of Team Saber had their status changed to killed in action.

Personality and traits
Olivia is known as the stealthiest Spartan in Gamma Company and is consequently called "O" for short because she is "as whisper-quiet as her vowel namesake. Kurt Ambrose believed that Olivia could have been wearing fluorescent orange fatigues and still blend in with the terrain. Olivia has a fear of "white fire" generated by a plasma discharge. According to psychologists this is because she saw her family die in a plasma strike, though she can no longer remember the details of the event herself.

Olivia is of African descent; Dr. Catherine Halsey estimated that her origins were in the Horn of Africa.

List of appearances

 * Halo: Ghosts of Onyx
 * Halo: Glasslands
 * Halo: Last Light
 * Halo Mythos: A Guide to the Story of Halo