Along with Jedi MasterQuinlan Vos, whom Ti found inside the prison's solitary confinement, Ti decided to infiltrate Tok's fortress and perform acts of sabotage in order to assist the Republic forces in their assault. After Ryyk was killed by a scrange creature on approach to the fortress, the trooper was assigned to take out the fortress's deflector shield generator single-handedly, while the others would try to take out Tok's powerful ion cannons, or capture the clan leader himself. The trooper succeeded in reaching his target but was fatally wounded by Tok's soldiers who guarded the generator. After Tok's men left him for dead, the trooper rigged his weapon on overload, and it exploded, destroying the generator and killing the trooper in the process. The trooper's sacrifice was one of the key factors that allowed the Republic to win the battle.
The trooper fights beside Shaak Ti on Brentaal IV.
However, the intelligence report had little to do with reality, and the Republic army faced heavy resistance from the rebels, who were assisted by Confederate battle droids. Tok himself commanded his troops from a ground fortress, which harassed Republic landing troops with fire from its powerful ion cannons, forcing Koon to recall all remaining landing craft from the surface. The fortress itself was surrounded by an energy shield, protecting it from orbital bombardment. Within the first few moments of the battle, the Republic lost more than a quarter of its forces, including General Kon Ray. As they fought the enemy, Ti, the trooper, and two of his comrades were cut off from the rest of Ti's forces. Koon then informed Ti of a prison facility located just north of their position. Ti planned to occupy the building and rally her forces from there. The trooper and his two clone brothers followed the Jedi General to the prison building, witnessing from afar that a battle was raging there.[3]
Once Ti and the troopers entered the prison, they found three escaped inmates—the HumanSagoro Autem, the ZeltronLyshaa, and the berserk WookieeRyyk—fighting the guards. Ti ordered the troopers to attack the guards, and they complied. In the ensuing firefight, one of the other troopers was cut down by blaster fire and the other one killed by the maddened Ryyk. The trooper himself suffered the loss of his helmet, which was slashed by the Wookiee's machete. Ti then used the Force to slam Ryyk into a wall, knocking him out, while the trooper and the inmates dealt with the remaining guards. As Ryyk started to come to his senses, the trooper asked permission from Ti to restrain him, but the Jedi instead calmed him down with the help of the Force. Sensing another presence inside the prison, Ti went to the solitary confinement, where she found Vos, who revealed to her that he had not been the one who sent the transmission. Intent on completing her mission, Ti devised a three-way plan. She, the trooper, Vos, and the inmates would split into three groups, and, using Vos's knowledge of the access points and the layout of Tok's fortress, they would attempt to either capture Tok, sabotage the fortress's shields, or take out the ion cannons. If any of those objectives was to succeed, it would greatly improve the Republic's chances of winning the fight.[3]
The trooper sacrifices his life to destroy the shield generator.
Ti contacted General Kolar, who was still fighting on the surface, telling him to attack the fortress from the north, distracting its defenders, while the sabotage teams would approach from the south. Koon, meanwhile, would seemingly withdraw all his forces, only to return four hours later when the sabotage had been performed. Autem, Lyshaa, and Ryyk were initially reluctant to participate in the sabotage, but they agreed when Ti promised them amnesty, despite the fact that Lyshaa had been serving her time for murdering Ti's Padawan, Fe Sun. The group then set off toward Tok's fortress, going through the sewers, where they were attacked by a scrange creature, which killed Ryyk. With an uneven number of operatives left, the trooper was assigned to attack the fortress's shield generator by himself. While Ti and Lyshaa left to confront Tok, Vos and Autem—whose target was the cannons—accompanied the trooper for some of the way before they had to split up.[3]
On their way, the three witnessed a number of Brentaal rebels moving captured Republic clone troopers. Seeing this as an opportunity, Vos and Autem came up with a plan to fool the guards. The trooper posed as their prisoner, while the two moved toward the rebels. Autem, who had been a Senate Guard and thus accustomed to how security worked, told the rebels that he and Vos were transporting the "prisoner" for questioning, and the rebels let the three through. After that, Vos gave the trooper final directions to the shield generator, and the team split up. The trooper managed to reach the generator unnoticed but found it heavily guarded; Lyshaa had switched sides and informed Tok of the infiltration teams, and he had alerted the fortress's guards. With time running out, the trooper charged the guards with his blaster rifle blazing, cutting down several of them before being blasted onto the generator core by a shot from a grenade launcher and losing his consciousness from heavy wounds. The guards believed him to be dead and left the generator room, and soon after that the trooper regained consciousness. Knowing his injuries to be fatal, and determined to finish the mission at all costs, he rigged his blaster to overload and remained seated on the generator as his weapon blew up, annihilating both him and the generator. That, combined with Vos's and Autem's successful destruction of the cannons, Ti's killing of Tok, and Lyshaa's death by one of the fortress's traps, ensured the conquest of Brentaal IV by the Republic forces.[3]
Vos: "Trooper, this is where we split up. Take the left corridor while we go up."
Autem: "And try not to talk so much."
The trooper: "Roger."
―Sagoro Autem, making fun of the trooper's silent nature[src]
Like all clone troopers, the trooper stood 1.83 meters tall.[1] He had blackhair and brown eyes. The trooper was cautious, offering to Ti to restrain Ryyk, who had killed one of the clones and damaged the trooper's helmet. He was generally very quiet and not talkative, a fact that Autem jokingly acknowledged by telling him not to talk so much right before they parted ways on the way to their respective sabotage targets. The trooper was a loyal soldier, and he was willing to sacrifice his life in the name of the Republic. Before his death, the trooper took solace in the fact that he had done his duty to the best of his ability.[3]