Mission to Coruscant (Desolator crisis)

During the Cold War between the Galactic Republic and the Sith Empire, a young Jedi Knight—the former apprentice of Jedi Master Orgus Din—was sent on a mission to the Republic capital of Coruscant to investigate a dark presence there. Accompanied by the astromech droid T7-O1, who had helped the young Jedi put a stop to the recent Flesh Raider uprising on the Jedi Order's homeworld of Tython, the Knight worked with the Republic Strategic Information Service and the Coruscant Security Force to stop the Sith Lord Tarnis from activating the Planet Prison superweapon.

After a gang of thieves stole the design files for the Planet Prison from a military warehouse on Coruscant, the Strategic Information Service tracked the thieves back to the criminal organization known as the Migrant Merchants' Guild. The newly-arrived Jedi Knight and T7-O1 were immediately sent to recover the files, but Doctor Eli Tarnis—the Planet Prison's designer and secretly a Sith Lord who had been undercover as a Republic scientist—orchestrated his own kidnapping by his allies in the Black Sun criminal syndicate so that he could proceed with his plans.

Chasing the kidnappers to the Coruscant Spaceport, the Padawan Kira Carsen and the CSF were aided by the Knight in retaking the hangar where the criminals were holed up and discovered that the kidnappers were actually a decoy. Tarnis had retreated to the territory of the paramilitary Justicars' Brigade, but the Jedi unknowingly followed another false lead into Black Sun Territory in a vain attempt to rescue the scientist. After staging a successful assault on the syndicate's headquarters with the help of an elite CSF team, the Knight failed to find Tarnis—but instead discovered Tarnis' true identity and his plans for the Planet Prison.

As the Republic scrambled to secure their other jeopardized weapon projects from the Empire, Carsen and the Knight tracked Tarnis to the Justicar's Sector, only to find that he had murdered the Planet Prison design team and stolen the superweapon after tricking them into bringing it to him. With the help of a dying scientist, the two Jedi traced the Planet Prison's signal to the ruins of the Jedi Temple, and they confronted the Sith Lord in the depths of the damaged edifice. Tarnis, who revealed his identity as the son of the Sith Lord Darth Angral, battled the pair in a fierce duel before holograms of his father and Angral's apprentices as the Planet Prison inched ever closer to activation. To Angral's fury, the duel ended with the death of Tarnis at the hands of the Knight, and the Sith Lord would embark on a crusade of vengeance against the entire Republic in response.

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