General Eviar Seldec, Commander of the Dark Vanguard and Sith apprentice to Valin Aresh, had arrived on Toprawa with four members of the Dark Vanguard in search of the Architect of Betrayal, a long-buried Sith superweapon. Discovered the Architect and its centerpiece, the Betrayer's Heart, Seldec employed hundreds of slaves to excavate the Architect.
Jedi Knight Gennic Forgey arrived on Toprawa to investigate the Sith presence, but was captured. Sith Lord Darth Alecto was also captured, as were Tirien Kal-Di and his Padawan, Narasi Rican, when they came to rescue Gennic. Seldec sentenced Alecto to death, but Tirien tipped her off to the plan, and she managed to escape custody. She subsequently recovered her own lightsaber and slaughtered the Aresh soldiers guarding the caverns' power generator. Destroying the generator, Alecto shut down power to the mines.
Freed from their cell, Narasi and Gennic recovered their lightsabers and found their way to the Architect's cavern. When a Vanguardian discovered Narasi and attacked her, Gennic intervened. Seldec attempted to use the Betrayer's Heart on Narasi, but Tirien tackled him off a ledge and knocked the Heart from his hand into the crowd of slaves.
A riot broke out among the slaves, some attempting to flee and others turning on their overseers. Tirien dueled General Seldec and one of the Vanguardians while Gennic fought another. Narasi raced the third through the crowd for the Betrayer's Heart. Due to the intervention of Cssarti Chawa, a Mrlssi slave, Narasi got hold of the Heart first. Meanwhile, a Wookiee slave beat Gennic's attacker to death.
The Vanguardian chasing the heart used Force wound on Narasi, causing her to drop the amulet. Gennic managed to recover it first, and fell back under the Vanguardian's assault. Narasi went to her master's aid; Tirien was wounded and struggling against two enemies at once. Seeing the opportunity, Tirien urged Gennic to destroy the amulet. The Jedi sacrificed himself, impaling the Heart with his lightsaber.
The destruction of the Betrayer's Heart killed Gennic and his Vanguardian attacker instantly, severely damaged the Architect of Betrayal, and caused the caves to collapse. Seldec and his surviving Vanguardian fled one way, while Cssarti led Tirien and Narasi out another. In the cave-in, the Architect was completely buried anew.