Assassination of Viento

Under the guise of a defector from the Jedi Order who had succumbed to the Dark side, Quinlan Vos was actually an undercover operative for the Republic's, having infiltrated the inner circle of Count Dooku's Dark Acolytes. Initially tasked with spying for the Republic, his focus shifted over time towards uncovering and potentially eliminating the enigmatic "second Sith," Dooku's master, a figure the Count had alluded to in a conversation with Obi-Wan Kenobi on Geonosis. This pursuit gradually became an obsession for Vos, a fact of which Count Dooku was fully aware, though Vos remained ignorant of this.

During a discussion initiated by Dooku about Sith traditions, Vos attempted to ascertain the identity of the second Sith, arguing that Dooku could not ascend to the title of Sith Master while his own master remained alive. While Dooku withheld any direct revelations, he tasked Vos with a mission to Coruscant to assassinate a specific individual, providing veiled suggestions that the target was, in fact, the second Sith whom Dooku was now prepared to eliminate. Vos, believing he was serving the Republic, eagerly accepted the mission.

Disguised as Kiffar general Zac'ryah Vos, Quinlan Vos journeyed to Coruscant, accompanied by Khaleen Hentz who was also disguised as a Kiffar. Upon his arrival, he received confirmation from Dooku that his target was Senator Viento.

Under the cover of darkness, Vos infiltrated Viento's apartment. By hiding his presence in the Force, he successfully bypassed both Senate Guards and Master K'Kruhk, who was also guarding the Senator. However, the moment Vos activated his lightsaber, K'Kruhk detected the sound and the scent of ozone, and Viento began to stir. Fearing intervention and anticipating resistance from Viento, Vos acted swiftly to complete his mission. Quinlan's realization of his error came too late. Only after delivering the fatal blow did he understand that eliminating Viento would not have been so straightforward had he truly been a Sith. Instantly, K'Kruhk burst into the room and attacked Vos, accusing him of betraying his Jedi teachings. Their battle spilled out of the window and onto the roof of a hover train, where Vos severely wounded K'Kruhk, forced him off the train, and fled. He then returned to Dooku, demanding explanations and informing him that Viento was not a Sith. Dooku feigned amusement, claiming he never stated Viento was a Sith, but rather an agent who had attempted to betray him.

Despite the post-mortem discovery that Viento was allied with the Separatists and involved in sabotaging Loyalist senators' speeders, the assassination itself nearly convinced the Jedi Council that Vos had genuinely fallen to the Dark side.

Viento's body was frozen in carbonite and placed within the Senatorial Tombs. A year later, Quinlan Vos, who had since rejoined the Jedi Order, entered the Senatorial Tombs to employ psychometry on Viento's frozen remains in an attempt to gather information regarding Finis Valorum's death, an event in which Viento was also implicated.