In the year 44 ABY, a significant confrontation transpired near the pumping station within the city of Kesla Vein on the planet Nam Chorios. This clash involved three Sith Sabers from the Lost Tribe of Sith, commanded by the Saber known as Tola Annax, who launched an assault against the exiled Jedi Grand Master Luke Skywalker, his son Ben, and the ostracized Sith apprentice Vestara Khai. The Sith forces had been deployed with the mission to seize Khai and eliminate the Skywalkers; furthermore, both factions were actively seeking the dark side entity named Abeloth. These objectives culminated in a lightsaber battle between the opposing groups. With Annax observing, her three subordinates engaged in combat with the Jedi and Khai in three separate one-on-one duels, resulting in their swift demise. Annax made her escape, and shortly thereafter, the Jedi group faced yet another assault from their adversaries.
Approximately six months prior, in 43.5 ABY, the exiled Jedi Grand Master Luke Skywalker and his son, the Jedi Knight Ben Skywalker, discovered that a dark side entity known as Abeloth was responsible for a Force psychosis that had afflicted several Jedi Knights within the New Jedi Order. The Lost Tribe of Sith—a sect of Sith originating from the planet Kesh—also encountered Abeloth within the Maw, leading High Lord Sarasu Taalon to persuade the Skywalkers to form an alliance with the Sith in order to vanquish Abeloth. However, their attempt to destroy the entity proved unsuccessful, and the partnership was dissolved.
The Skywalkers, accompanied by the outcast Sith apprentice Vestara Khai—who was compelled to assist the Jedi after killing Taalon when the High Lord began a transformation into a being resembling Abeloth—pursued Abeloth and located her on the planet Nam Chorios in 44 ABY. Luke Skywalker had established a blood trail leading to Abeloth, enabling him to pinpoint her location on the world. The Sith also sought to find Abeloth, and Khai secretly informed her father, Gavar Khai, that Abeloth and the Jedi group were on Nam Chorios. In response, the elder Khai dispatched multiple Sith Sabers to the planet with orders to locate and capture his daughter, as well as to eliminate the Skywalkers.
Under the leadership of the Keshiri Sith Saber Tola Annax, a team composed of Annax and three additional Sabers discovered the Skywalkers and Vestara Khai near the pumping station in the town of Kesla Vein. As the Jedi group returned to their airspeeder, Annax leapt onto their vehicle and demanded Vestara's surrender. When she refused, Annax ordered her team to attack the Jedi and the Sith girl. While the Keshiri Saber remained behind, the other three engaged each of their three enemies in individual lightsaber duels. Vestara fought against a petty officer serving under her father; he attempted to use the Force to hurl stones at her, but she managed to defeat him by impaling her blade through his heart. Simultaneously, Luke Skywalker bisected his enemy in two and moved to assist his son. However, the younger Skywalker decapitated his opponent shortly thereafter. Following her team's defeat, Annax escaped by using a cable to ascend a ravine before piloting away in another airspeeder. Furthermore, the Keshiri destroyed the Jedi's speeder, leaving them without transportation.
The Sith petty officer utilized the Force during the duel, an act that triggered a Force storm somewhere on the planet. The tsil crystals on Nam Chorios amplified and redirected Force energy. Shortly after the duel, Luke Skywalker received a message from the journalist Kandra Nilitz, who successfully convinced the Grand Master to meet with her. Shortly before reaching Nilitz's landspeeder, the Jedi group was once again forced to repel several Sith, but they escaped and continued their search for Abeloth in the city of Crystal Valley. The Sith, in the meantime, also continued their search for Abeloth and the Jedi, which led to another encounter between the three parties.
This skirmish was first depicted in Fate of the Jedi: Conviction, the seventh novel in the Fate of the Jedi series. Conviction was authored by Aaron Allston and released in 2011.