Vector represents the eighth story arc within the Star Wars: Knights of the Old Republic comic book series. It serves as the opening segment of the Star Wars: Vector cross-series narrative.
One month transpires following the events detailed in Knights of Suffering. At a memorial service held for Raana Tey, a member of the First WatchCircle, they collectively experience a vision. This vision depicts Karness Muur achieving galactic domination through the deployment of a rakghouls army, brought into existence by the Muur Talisman. Driven by the fear that Zayne Carrick might exploit this dangerous artifact, which is believed to be located somewhere on Taris, they resolve to dispatch Celeste Morne, a Jedi Shadow and clandestine operative of the Jedi Covenant, to intercept him.
Within the Undercity of Taris, constable Noana Sowrs finds herself pursued by rakghouls. Just as she is on the verge of being overwhelmed, Celeste Morne intervenes, swiftly eliminating the monstrous threat. The constable reveals that Cassus Fett's strategy to ambush and disperse the resistance has been successful, forcing the surviving members into the Undercity. Celeste notices that Noana has been bitten and eliminates her immediately after she transforms into a rakghoul. A significant explosion heralds the arrival of Zayne Carrick and Marn Hierogryph, who are also being pursued by a horde of rakghouls. After Celeste rescues them, they opt to accompany her, despite her initial reservations. Soon after, they encounter a group of Mandalorian Neo-Crusaders, commanded by Pulsipher, who have just discovered the Muur Talisman. Celeste trails them, with Zayne and Gryph following her discreetly.
The trio conceals themselves aboard the ship transporting Pulsipher's team to Jebble. Shortly before landing, Pulsipher succeeds in activating the Muur Talisman, which then affixes itself to his arm and contaminates the surrounding Mandalorians. Upon landing, Pulsipher proceeds to his laboratory, pursued by Celeste, while Zayne and Gryph are noticed by a Mandalorian Sergeant. Mistaking them for new recruits, the sergeant directs them back to "their group." This group is composed of various criminals and villains hailing from Outer Rim worlds, including Wargo and Frazznik, individuals Zayne and Gryph had previously encountered on Taris. The Rally Master declares that any recruit who adheres to the Resol'nare will be recognized as Mandalorian and announces the army's impending invasion of Alderaan. Rejoining Celeste, Zayne and Gryph, now clad in Mandalorian armor, decide to infiltrate the Ice Citadel. Gryph feigns leadership of Tarisian slicers to assist Pulsipher, a deception that proves convincing enough for the guard to grant them entry into the War Forge. Once inside, Gryph becomes separated from Zayne and Celeste, who then encounter a group of Mandalorian Neo-Crusaders. Abruptly, these warriors transform into rakghouls, leaving Zayne and Celeste with no alternative but to flee. However, they soon realize that escape is impossible, given the millions of recruits outside the Citadel and the imminent invasion, which threatens to escalate the Rakghoul plague into an intergalactic crisis.
Through sheer luck, Zayne and Celeste manage to evade their pursuers. In the ensuing conversation, Zayne discloses to Celeste that his masters, rather than himself, were responsible for the Padawan Massacre of Taris, and he also shares information about the Jedi Covenant and its leader, Krynda Draay. Celeste is taken aback by this revelation and attempts to justify the Covenant's actions, without revealing her own involvement. Meanwhile, in the Data Center, Gryph discovers Lucien's record detailing the history of the Muur Talisman and its creator, Karness Muur, along with a mention of Celeste Morne as one of the Covenant's agents. In the communication dome, Celeste contacts Lucien Draay, who instructs her to retrieve the Talisman and eliminate Zayne Carrick. Celeste, however, is conflicted and refrains from striking him down when given the opportunity. Simultaneously, Zayne contacts Cassus Fett and cautions him against landing due to the plague. Fett is initially skeptical but decides to verify the accuracy of Zayne's report.
Zayne returns to the citadel in search of Gryph but is ambushed by rakghouls and taken to Pulsipher's laboratory. There, Pulsipher demands any knowledge Carrick possesses regarding the talisman. Zayne attempts to persuade Pulsipher to relinquish the artifact, but Pulsipher threatens to imprison Zayne within another Sith artifact in his possession – Dreypa's Oubliette – a place where any living being placed inside will endure an eternal existence worse than death, until the galaxy collapses upon itself. Suddenly, the Talisman detaches itself from Pulsipher and moves toward Zayne. Losing control of the rakghouls, Pulsipher is immediately devoured by them, but Celeste appears and slays them afterward. Zayne hopes that by controlling the Talisman he could stop rakghoul plague from spreading, but Celeste demands that he is not supposed to do that and struggles to stop talisman from attaching itself to Zayne. Gryph arrives and demands that both stay away from the talisman, and in that moment Celeste calls talisman to herself. The artifact immediately attaches itself to her and after a moment of shock and pain Celeste is able to see the spirit of Karness Muur. More rakghouls arrive, but at the moment they are no danger to Zayne and Gryph, because they are now controlled by Celeste.
Under the command of Celeste Morne, the rakghouls eliminate the remaining Mandalorians, utilizing their own vehicles and weaponry. Celeste has undergone a radical transformation, now viewing the destruction of the Mandalorian army as justified and even condoning the killing of individuals, rationalizing that the rakghouls must feed. Meanwhile, Gryph informs Zayne that Celeste is working for Lucien and the Covenant. Zayne is shocked and angered by that and asks how Celeste could work for them after so many wrongs they have done. This pushes Celeste even further to the Dark Side, so she decides to kill Carrick, but he finally manages to get her to sense by indicating that she is now commanding the Sith army she was devoted to stop. Celeste becomes herself again – she now feels Karness Muur struggling to use rakghouls to do unthinkable damage to the galaxy and, weeping, asks Zayne to kill her and run. Zayne however has a different idea – he decides to put Celeste into Dreypa's Oubliette, so the power of the talisman could not penetrate it. Before getting inside Celeste gives Zayne the key of the Sanctum of the Exalted on Odryn and asks him to get her there and to contact Krynda afterward. Zayne closes the Oubliette, promising that he'll see her again later.
The again mindless rakghouls are chasing Zayne and Gryph, who escape from them to the top of the citadel, where they are picked up by timely arriving Moomo Williwaw. Zayne asks Alek to go back for Celeste, but there is no time – the Mandalorians have arrived. It becomes clear that Fett took Carrick's warning seriously – the fleet executes nuclear bombardment of Jebble, wiping out all life on its surface.Cassus Fett thanks Zayne and says that he is in his debt, but Zayne is crushed by the repetition of Serroco. While Alek is amazed by what a single talisman could do, Shel asks Zayne what he plans to do next. Zayne decides to honor Celeste by doing exactly what she told him to do – expose the crimes of the Jedi Covenant and clear his name in process. The crew takes Moomo Williwaw to Odryn, unknowing that the Oubliette with Celeste Morne and Muur Talisman inside it is perfectly intact.