"Tarnis will use the Planet Prison against Coruscant. He could trap us here forever. Paralyze the Republic be holding us hostage. You're our only hope of stopping that."
Jedi Knight: "I'll stop him, General—but I need to know where he is."
Kira Carsen: "That's where I come in. I just traced that holocall we intercepted from the Black Sun base. Tarnis was communicating from down in sector 439."
Var Suthra: "Justicar territory! Tarnis knows we're not welcome there."
Learning from the kidnappers' leader that Tarnis had been taken to the gang's territory, the Knight and T7 worked with SergeantNidaljo and the Special Tactical Unit of the Coruscant Security Force to attack the headquarters of Black Sun in an attempt to rescue the doctor. There, the Jedi learned an astonishing fact—Tarnis was a Sith Lord, and he had hired the thieves and the kidnappers to serve as distractions. After defeating the Black Sun leader Salarr, the Knight and T7 returned to the Senate Building, where they spoke with Suthra about Tarnis' deception. The traitor had stolen the actual prototype for the Planet Prison, and the entire research team had also disappeared. Urging the general not to panic, the Knight was interrupted by Carsen, who had traced Tarnis' holotransmission to the territory of the Justicars' Brigade. The Justicars were a paramilitary organization that had cut ties with the rest of Coruscant following the Sacking of Coruscant by the Sith over ten years earlier, and they had forced out both criminals and Republic personnel from their sector.[1]
"Tarnis tricked us. Said you Jedi were going to shut the project down. Told us to bring the Planet Prison here. Keep it safe. Thought we were saving the Republic. We brought Tarnis the prototype. He turned on us. Killed everyone."
Believing that the Knight should not face a Sith Lord alone, Kira took T7's place at the Jedi's side while the droid remained at the Senate Building. The two Jedi took an air taxi to the Justicars' Sector and fought their way through the hostile paramilitaries in the area.[3] While the Jedi did not know it at the time, the Justicars were actually actively trading weapons and supplies with the Sith Empire, and therefore had no objections to Tarnis' presence in their territory.[7] The Knight and Carsen eventually made their way to the Jusicars' main detention center. Within the base, they found a scene of carnage in the room where Tarnis had sent the holotransmission.
With his dying breath, Jonkan aided the Knight in locating the Planet Prison
The room was littered with the bodies of the research team, and the Planet Prison prototype was nowhere to be found. One of the scientists, a man named Jonkan, was still alive, and the two Jedi rushed to help him. The injured man told the two that Tarnis had tricked the team into bringing him the prototype by telling them that the Jedi wanted to shut down the project. However, when they arrived with the device, Tarnis had turned on them and massacred the scientists, taking the device as he left. The Knight tried to reassure Jonkan that he would survive, but Jonkan refused to allow the Jedi to waste time on his injuries—they were too sever—and instead told the Jedi about the Prison's weaknesses. The device generated enormous amounts of heat and required time to charge to full capacity, giving them time to find and destroy the weapon before it could fire. Urging the Knight to save Coruscant, Jonkan gasped his final breath and passed away. [3]
"Running a thermal scan… whoa, the technician wasn't kidding. Somethings's really lighting up. Tracking… Here we go. Sector 167, coordinates 8863… Oh, you've got to be kidding me. The signal's coming from the ruins of the Jedi Temple."
Using Jonkan's information, Carsen was able to track the location of the Planet Prison using the room's computers. Tarnis had taken the weapon to the ruins of the Jedi Temple, as a final insult to the Jedi.[3] With no time to spare, the two Jedi raced through the Works, Coruscant's industrial and infrastructure district, towards the Temple and their final confrontation with Tarnis.[2]
The raid on the Justicar Detention Center was created for Star Wars: The Old Republic, a massively multiplayer online role-playing game released by BioWare on December 20, 2011. It appears in the Jedi Knight class story mission "Tracking Down the Traitor", where the player pursues the Sith Lord Tarnis to the Justicars' Sector in an attempt to find the Planet Prison superweapon. While the mission does not feature any alignment choices, it is notable for being the first mission where the player receives Kira Carsen as a companion. She serves as a guest companion for this and the next mission, which means that she cannot be sent on crew skill missions.[3]