The Confederacy of Independent Systems launched a mission around 22 BBY during the Clone Wars to free Trade Federation Viceroy Nute Gunray, who had been captured on Rodia by the Galactic Republic. Gunray was being taken in the Star Destroyer Tranquility to Coruscant for trial by Jedi General Luminara Unduli, Jedi Commander Ahsoka Tano, Clone Commander CC-1004, nicknamed "Gree," and Senate Commando Captain Faro Argyus. However, the latter was a long-time ally of Count Dooku, and had been paid to participate in freeing the viceroy. As the Jedi began interrogating Gunray aboard the Tranquility, Dark Acolyte Asajj Ventress took a boarding party of Vulture droids and several boarding craft to the Republic warship.
Once battle droids had boarded the Star Destroyer and attacked Unduli and clone troopers of Green Company, Ventress planted explosives in the vessel's engine room before confronting Tano outside of Gunray's cell. After Unduli arrived with Commander Gree on the detention level, Ventress activated her explosives, crippling the entire ship. Ventress escaped, and while Unduli instructed Tano to stay and guard Gunray, the Jedi Master pursued the Dark Acolyte to the engine room. Tano disobeyed Unduli's orders and proceeded to assist Unduli in her duel against Ventress, however. Meanwhile, Argyus betrayed the Republic and freed Gunray. The captain engaged Gree in close combat, but Gunray managed to sneak up behind the clone commander and knocked him out with a blaster. Argyus and Gunray then stole a Republic frigate and escaped from the Tranquility, while Ventress joined them, jettisoning from the Star Destroyer in an escape pod to the fleeing vessel.
Around 22 BBY, during the Clone Wars, Trade Federation Viceroy Nute Gunray was captured on Rodia by Senators Padmé Amidala and Onaconda Farr of the Galactic Republic. Gunray was to be taken to Coruscant to stand trial for his war crimes, and Jedi Master Luminara Unduli was assigned to oversee his transfer to the galactic capital. In the midst of an ongoing battle, Jedi General Anakin Skywalker learned that his secret wife, Amidala, had been involved in Gunray's capture and sent his Padawan, Jedi Commander Ahsoka Tano, to protect her from potential danger from the Confederacy of Independent Systems. Receiving clearance from Masters Yoda and Mace Windu of the Jedi High Council, Tano joined Unduli and Clone Commander CC-1004, nicknamed "Gree," in escorting the viceroy to the waiting Venator-class Star Destroyer Tranquility via a Consular-class cruiser. Upon the group's arrival on the Star Destroyer, Senate Commando Captain Faro Argyus and his fellow Senate Guards placed Gunray in a cell, ready for interrogation.
Meanwhile, Dark Lord of the Sith Darth Sidious learned of Gunray's capture and contacted his Sith apprentice, Darth Tyranus, who was with a Separatist fleet of Munificent-class star frigates under his command. Count Dooku—as Tyranus was also known—stated that he already had a plan in operation to rescue Gunray involving Dark Acolyte Asajj Ventress, and while Sidious was doubtful of her abilities, he allowed Dooku to proceed. Ventress planned to infiltrate the Tranquility, and as a squad of B2 super battle droids attacked the clone troopers aboard the Star Destroyer, she would plant explosives to cripple the cruiser. Once the Tranquility had been damaged, Ventress planned to lure the Jedi away from Gunray and signal Argyus—who was a long-time ally of Dooku and had been given a hefty payment to assist the Confederacy in the mission—to free Gunray. Ventress departed Count Dooku's fleet with a squadron of Vulture droids and several Droch-class boarding ships to attack and board the Tranquility.
As the Jedi began to interrogate Gunray inside his cell block, the Confederate boarding party arrived. With Vulture droids attacking the Tranquility, the captain of the cruiser, on the bridge of the Star Destroyer, reported the appearance of the boarding craft to Gree, Argyus, and the Jedi. Gree alerted Green Company and sent the troopers to repel the enemy. The three Confederate boarding ships breached the hull of the Tranquility and lodged themselves in the Star Destroyer near its hangar bays. The troopers of Green Company arrived and took cover behind several crates from the battle droids that were being deployed from the boarding craft. In the ensuing crossfire, the droids attacked the over-matched clones with lasers and rockets, and the advance clone forces were defeated, including Green Leader.
Ventress emerged from one of the boarding ships and quickly decapitated the last surviving clone trooper with her paired lightsabers. Stealing the trooper's comlink, Ventress cut a hole in one of the vents in the ceiling of the hangar with her lightsabers and proceeded to the Tranquility's engine room. The Dark Acolyte was able to slip past 327-T, the WED-15 Treadwell droid that was inspecting the area, and plant several thermal detonators around the Star Destroyer's main reactors before escaping and heading to the detention level to personally confront the viceroy's captors. Meanwhile, Tano remained with Argyus to guard Gunray while Unduli and Gree went to assist the clone troopers in fighting the droids. Elsewhere, super battle droids marched through one of the Star Destroyer's hallways, engaging six remaining Green Company troopers. The troopers' numbers were cut in half, but they were saved by the arrival of Unduli and Gree. The Jedi and the troopers attacked the battle droids and eventually defeated their opponents, leaving the hallway ridden with fallen battle droids. Nevertheless, Unduli sensed that their troubles were not over. Indeed, Ventress was preparing to face off with Tano and Argyus on the detention level at that very moment.
As Argyus received word that the enemy had been repelled and reported the update to Tano, Ventress cut a hole in the detention level's ceiling and knocked the two Senate Commandos manning the control station of the Tranquility there unconscious. The Dark Jedi then confronted the Padawan, and the two exchanged insults before engaging in a lightsaber duel. While the pair fought, Unduli overheard the lightsaber clashes and quickly headed back for the detention block with Gree and the remaining clones. Tano ordered Argyus and the other Senate Commandos to open fire on Ventress, but the Dark Acolyte deflected and rebounded the lasers, killing all of the Commandos save for Argyus. The Senate Commando captain himself blocked the reflected shots with his shoulder armor, but in order to keep the Separatist agent's cover from being compromised, Ventress attacked him as well and Force-pushed him toward the control station, knocking him unconscious. Breaking away from dueling Tano, Ventress proceeded to deactivate the laser gate of Gunray's cell. As the Padawan arrived and slashed at the viceroy, Ventress kicked her into the detention cell. Gunray quickly stepped out and reactivated the lasers, trapping Tano. Nevertheless, Unduli arrived at the detention blocks with the clone troopers, changing the course of the fight with her reinforcements. Running to engage Ventress, the Jedi Master also telekinetically deactivated the laser bars of Tano's cell. Ventress dueled both Jedi at once, and Unduli ordered the Dark Acolyte to surrender.
With no intention of giving up, Ventress activated the explosives planted in the engine room. The Tranquility shook under the resulting blast, and as everyone in the room lost their balance, Ventress took the opportunity to Force-push Unduli to the ground. The Jedi Master rolled aside, avoiding several lightsaber slashes aimed at her head. Although the clone troopers opened fire at the Dark Acolyte, Ventress jumped over them and opened a turbolift shaft door with the Force. The Dark Acolyte escaped, plunging her lightsabers into the side of the turbolift shaft to control her descent. Checking the Star Destroyer's sensors and controls, Argyus reported that all systems—including communications—had been disabled from the explosives. Ventress had crippled the entire ship. While Gunray was taken back to his cell, Unduli decided to face Ventress alone. Although Tano, having previously faced Ventress, stated that the Dark Acolyte was too powerful for a single opponent and offered to help, Unduli refused the Padawan's assistance and left to face Ventress alone.
Following a trail of fallen clone troopers that the Dark Acolyte had left in her wake, Unduli arrived in the engine room. After the Jedi Master had entered the room, Ventress appeared and slashed at her, diffusing a pipe and injuring Unduli's left eye. The Jedi Master back flipped onto another reactor with Ventress in pursuit. While the two exchanged blows, Unduli commented on the sloppiness of Ventress's fighting style, seeking to distract her adversary. Enraged, Ventress jumped toward Unduli, and the two continued their fight with renewed force. Back on the detention level, Tano decided to disobey Unduli's order to guard Gunray and proceeded to assist her in her duel, believing that Ventress was too powerful for any one Jedi. As the lightsaber battle continued though the reactor room, Ventress and Unduli employed Force-pushes against each other. After a few moments, both Jedi Master and Dark Acolyte released the energy and were pushed backward.
Unduli jumped over Ventress, aiming several lightsaber blows before landing behind her. The pair turned back around to face each other, and Ventress lunged at the Jedi Master, but instead of slashing at her, she kicked her off the reactor to the floor far below. As Unduli fell and lost hold of her lightsaber, Ventress jumped up and detached several fuel pipes from the ceiling. Unduli tried to use the Force to avoid being crushed by the resulting falling debris, but her leg had been caught under one of the pipes. Taking advantage of Unduli's vulnerability, Ventress leaped to kill the Jedi Master, lightsabers spinning. However, Tano arrived in time to Force-push Ventress into an open pipe. The Padawan freed Unduli and retrieved her lightsaber for her, and Unduli accepted Tano's help. Ventress climbed out of the pipe and, making use of Dooku's training to duel more than one Jedi at once, engaged the two Jedi in simultaneous lightsaber combat. Ventress eventually ascended the large reactors and disappeared from sight to keep Unduli and Tano occupied. Believing Ventress to be after Gunray, the Jedi jumped up and searched for Ventress, but the Separatist agent instead used her stolen comlink to secretly signal Argyus to free the viceroy.
On the detention level, Argyus received Ventress's signal and killed both of his Senate Commando companions. Engaging Gree in blaster combat, the traitorous Senate Commando forced the clone to take cover from the incoming fire. While the two exchanged laser shots, the captain freed Gunray from his cell and used the viceroy as a "living shield," forcing Gree to cease fire to avoid killing the prisoner. Back in the engine room, Unduli and Tano came across 327-T, who had been trapped under some debris, and freed the droid before continuing their search for Ventress. Receiving word of Argyus's betrayal form Gree, the two Jedi headed back to the detention level to assist the clone. Intending to keep them occupied, Ventress hurled a pipe at them with the Force. Turning around, Unduli severed the projectile, and she and Tano continued their duel, engaging Ventress in a saberlock.
Gree shot Argyus's blaster out of his hand, but as the clone commander ordered Argyus to surrender, the captain shoved Gunray at the trooper. Gree pushed the viceroy aside, and Argyus used the clone's momentary distraction to kick his blaster out of his hand and his helmet off. As Gree confronted Argyus concerning his loyalty to the Republic, the captain bent down to grab the clone's fallen blaster. The commander punched the Senate Commando in the head, knocking him to the ground. As the clone commander took aim at the captain, however, Gunray sneaked up behind the clone and knocked him out with the butt of Argyus's blaster, mocking the unconscious clone's single-minded loyalty to the Republic. Back in the engine room, Tano and Unduli took turns advancing at Ventress, forcing the Dark Acolyte to give ground. The two Jedi cut through the debris that the Separatist agent Force-pushed at them, and the Jedi Master rebounded the last piece back at Ventress. The Dark Acolyte Force jumped, avoiding the projectile, and charged at the pair again.
As the duel continued, Argyus signaled Ventress with his comlink that Gunray had been freed. The Dark Acolyte broke off from her fight with the Jedi and jumped up, propelling herself off a reactor into an overlooking air vent. When Tano followed, Ventress threw a thermal detonator back at the reactor and escaped as the explosive detonated. Tano fell off the walkway of the engine room, but Unduli caught her and managed to pull her back up. Argyus and Gunray escaped in Unduli's Consular-class cruiser docked in the lower hangar, while Ventress disposed of two clone troopers guarding the Star Destroyer's escape pods. Stealing a pod for herself, Ventress departed the Tranquility, and Tano and Unduli arrived too late to prevent her from escaping. With the Star Destroyer still crippled, the Jedi could only watch from one of the Tranquility's viewport windows as the Separatist agents fled with the newly-liberated Viceroy Gunray.
In space, Ventress docked her escape pod to the Consular-class cruiser and climbed aboard the frigate. Yet, when Argyus claimed credit for the mission, Ventress executed him with her lightsaber. Back aboard the Tranquility, Tano and Unduli informed Skywalker and Jedi Grand Master Yoda of Gunray's escape via holotransmission. Argyus and the viceroy had used a Republic vessel to escape, but Unduli had been able to track the ship through its tracking beacon. Unduli had alerted Master Kit Fisto and his fleet, which had been near Gunray's position, to follow the viceroy's signal and recapture him. After Unduli reported the developments to Yoda and Skywalker, Tano left Unduli and departed the Tranquility to rendezvous with her master.
Meanwhile, Dooku had come to doubt the abilities of his best general, Grievous. In order to reassess the general's powers, the Confederate Head of State planted the Republic tracking beacon in Grievous's own lair on the third moon of Vassek in order to lure Fisto and his former Padawan, Nahdar Vebb, to the planet. Once the Jedi were in place, Grievous was able to hunt them for sport, allowing Dooku to review Grievous's abilities.
The battle first appeared in "Cloak of Darkness," an episode in the 2008 Star Wars: The Clone Wars television series. It featured the series introduction of Captain Argyus, who had previously appeared throughout the series' supplementary online comic series, and also featured Luminara Unduli, who first appeared in the series as a hologram in the episode "Destroy Malevolence." Additionally, the battle also appeared in the young readers book Star Wars: The Clone Wars: Ambush, while the duel during the battle appeared in the 2008 video game Star Wars: The Clone Wars: Lightsaber Duels.