In 1,391 BBY, Jedi Knight Suwo Tolp and his Padawan Tirien Kal-Di carried out a mission to Thisspias. Acting on intelligence that the New Sith Empire was using Thisspias to manufacture and distribute the Candorian Plague, the Jedi High Council order the two to shut down the Sith base.
Tolp and Kal-Di successfully infiltrated the subterranean plague center, using explosives to disrupt the process and wiping out dozens of Sith supporters and collaborators. Tolp dueled an Askajian Sith Lord overseeing the process and, while he was injured in the fight, ultimately killed her. Tirien, meanwhile, ran down the last of the plague canisters.
The two Jedi proceeded to the facility's hangar bay, where the found the Trandoshan Sith Lord Zygro and two Sith Acolytes, Alecto and Churka. Ordering his subordinates to prepare their shuttle, Zygro engaged both Jedi in a duel. He succeeded in killing Tolp, but was himself killed by Kal-Di. Knowing he was drained from his fight, Kal-Di forced Alecto and Churka to flee with what little they had aboard their shuttle rather than trying to duel them both at once.
Though the Acolytes escaped with a small quantity of the Plague and Tolp died in the mission, the Jedi Council considered the mission moderately successful and knighted Tirien.