Jedi Master Quinlan Vos and the bounty hunter Asajj Ventress embarked on a mission with the goal to assassinate Count Dooku. Dooku was scheduled to attend a gathering on Raxus Secundus, the capital world of the Confederate, where he was to be presented with the Raxian Humanitarian Award for his contributions during the Clone Wars. Earlier, the Jedi Council dispatched Vos to eliminate Dooku, hoping to expedite the end of the war. Vos sought the assistance of Ventress, who instructed him in the ways of the dark side of the Force. Despite their careful planning, Dooku proved too powerful, defeating and capturing Vos. Ventress managed to escape and alert the Jedi about Vos's capture.
Following the massacre of civilians on Mahranee by Count Dooku, the Jedi Council made the decision to assassinate the Separatist leader, aiming to bring a swift conclusion to the Clone Wars. Master Quinlan Vos was assigned this task by the Council: to eliminate Dooku. Vos accepted the assignment but also enlisted the aid of Asajj Ventress, a former Dark sider who worked as a bounty hunter. After a brief period working together as bounty hunters, Vos revealed his true identity, and Ventress agreed to assist in assassinating Dooku, driven by her hatred for her former Sith master.
Ventress brought Quinlan to Dathomir, her adopted homeworld, to train him in the practices of the Nightsisters, a dark side cult. Following intense training, Ventress learned from Sumdin, a Gossam contact within the Separatist ranks, that Dooku intended to visit Raxus Secundus, a planet located in the Tion Hegemony. Dooku's plan was to deliver a speech at a public celebration. After Vos completed his final trial, using the dark side to slay a crustacean creature known as The Sleeper, Ventress deemed him prepared to confront Dooku. Together, the two Force-users set off for Raxus aboard her starship, the Banshee.
Upon their arrival in Raxulon, the capital city of Raxus, Vos and Ventress disguised themselves and met with Sumdin at the spaceport. After Sumdin provided them with invitations to Dooku's event, Ventress used her lightsaber to kill her. When Vos expressed his disgust, Ventress explained that allowing Sumdin to live would risk the exposure of their operation. As they approached Raxulon's public square, the two Force-users employed mind tricks to persuade a guard to grant them access without a weapons check. The public celebration was a Separatist event to honor Dooku with the Raxian Humanitarian Award.
Count Dooku addressed the assembled crowd from a balcony on the Separatist Senate Building, with General Grievous at his side. During his address, Dooku praised the Confederacy for advocating change and equality. He then criticized the Galactic Republic and the Jedi for responding to demands for reform with military force. Before accepting the humanitarian award, Dooku emphasized the righteousness of the Separatist cause and disparaged the Republic's Clone troopers as enslaved beings sent to their deaths. As the public banquet began, the two assassins began their plan.
Ventress would draw Dooku away to a secluded location, while Vos would subdue Grievous and his battle droid escort. Asajj successfully mingled with the crowd, eventually encountering her former Sith master. She challenged Dooku to a duel at the overlook. The Count accepted but moved away discreetly to contact Grievous for reinforcements. Meanwhile, Vos ambushed Grievous and his battle droids. After a fierce fight, he trapped the cyborg general in a chamber and then went to join Ventress at the overlook. Upon arriving, Dooku attempted to contact Grievous but received no response, leaving him to face the two assassins alone.
Dooku tried to distract his foes by drinking some Alderaanian wine. Before Vos and Ventress could attack with their lightsabers, Dooku drew his own and dodged. As the three Force-users clashed, Quinlan remembered Asajj's teachings and embraced his pain and hatred to access his dark side abilities. Ventress managed to corner her former master, their blades locked together. However, Dooku shoved her aside, sending her sprawling to the ground.
Enraged by Dooku's attack on Ventress, Vos charged at the Sith Lord from behind. However, Dooku spun around and blocked Vos's strike with his lightsaber. As they fought, Vos tried to stab Dooku in the chest, but the Sith Lord dodged the attack. Vos then made the mistake of circling Dooku, ignoring Ventress's warnings. This allowed Dooku to use the Force to levitate Quinlan and slam him against a pillar, briefly incapacitating him. The Sith Lord then turned to Ventress and used the Force to hurl her against another pillar, knocking her unconscious.
Sensing Quinlan's grief and fear, the Sith Lord mocked the undercover Jedi, questioning how many Jedi vows he had broken to destroy him. Enraged by Dooku's taunts, Vos attacked the Sith Lord. Ventress stirred and tried to warn her former pupil not to listen to Dooku. Encouraged by Ventress's survival, Vos continued his lightsaber duel with Dooku. The Sith Lord then remarked that the dark side was stronger in Quinlan than in his former apprentice, Ventress. Dooku also attempted to create conflict between the two assassins by suggesting that Ventress had not properly trained him in the ways of the dark side.
Their duel was interrupted by General Grievous's arrival. Vos managed to kick him, sending the cyborg general tumbling over the railing. However, Grievous grabbed Ventress's arm, dragging her down with him. Fearing that Ventress would die, Quinlan physically attacked Dooku, kicking him hard in the face. However, Dooku seemed unharmed and instead provoked the Jedi into embracing his anger. Giving in, Vos fought Dooku, managing to knock the Sith Lord's lightsaber from his hand. With his lightsaber inches from Dooku's throat, Vos attempted to behead the Sith Lord.
However, Dooku seized Vos's wrist before he could strike and tackled him to the ground. Dooku subdued Vos by pressing his knee into the Jedi's back. Vos was unable to break free, as Dooku's strength was enhanced by the Force. Dooku then twisted his arm and deactivated his lightsaber. Meanwhile, Ventress landed on the edge of the lower level. Grievous landed on top of her, placing his metallic foot on her throat. The cyborg then grabbed Ventress and threw her down to the level below. Ventress survived her fall and fought off Grievous. As she fled Grievous and his droid reinforcements, she used the Force to retrieve Vos's fallen lightsaber.
Quinlan Vos and Asajj Ventress's attempt to assassinate Count Dooku failed due to the Sith Lord's command of the dark side and General Grievous's timely arrival. Having captured Vos, Dooku used Force lightning to knock the Jedi Master unconscious. As he lost consciousness, Vos saw Ventress fighting off battle droids and escaping into the sewers. Despite being pursued by Separatist droid forces, Ventress escaped offworld aboard her ship, the Banshee. Before fleeing, Ventress vowed to rescue her lover, Vos.
Meanwhile, Count Dooku imprisoned Vos at his palace on Serenno. There, Vos endured prolonged torture and psychological manipulation. Dooku turned Vos to the dark side and recruited him as his new Sith apprentice by revealing that Ventress had murdered his former Master, Tholme. Secretly, Vos planned to earn Dooku's trust to lead him to his mysterious master, Darth Sidious, and destroy the Sith Order once and for all. Refusing to abandon her lover to Dooku, Ventress organized a rescue mission with the help of Boba Fett's bounty hunter syndicate. However, Vos, consumed by hatred for Ventress, rejected her rescue offer.
The Raxus Secundus mission was featured in the 2015 novel Dark Disciple, penned by Christie Golden and adapted from an unproduced eight-episode story arc intended for Star Wars: The Clone Wars animated series. The arc was authored by Katie Lucas, Matt Michnovetz, and Dave Filoni. Spyros Tsiounis created the storyboards for the original arc's duel between Dooku, Ventress, and Vos.
In Star Wars: Galactic Atlas, Asajj Ventress is depicted wielding her red-bladed lightsabers instead of her yellow-bladed lightsaber.