Operation Shieldfall was a mission undertaken by the Sith that unfolded on the planet of Nam Chorios in 44 ABY. This Sith endeavor resulted in a confrontation involving the New Jedi Order, the Lost Tribe of Sith, and the dark side entity known as Abeloth. Following the dissolution of their fragile alliance, which had been formed with the aim of eliminating Abeloth, both the Jedi and the Sith relentlessly pursued her, as she had induced a psychosis among the Jedi ranks. Vestara Khai, a Sith apprentice, alongside Luke Skywalker, the Grand Master of the Jedi, and his son, Ben, tracked Abeloth to Nam Chorios. There, they encountered the Force-sensitive Theran Listeners and uncovered that the Therans had succumbed to Abeloth's influence. Khai communicated with her father, Gavar, who subsequently led a Sith flotilla to the planet. After a search for Abeloth across various locations, during which they were attacked on two separate occasions by Sith forces under the command of Saber Tola Annax, Vestara and the Skywalkers finally located Abeloth within the city of Crystal Valley.
Inside a pumping station located there, they discovered Valin Horn, a psychotic Jedi, alongside Abeloth, who had taken on the guise of Callista Ming, a former Jedi. Luke successfully extracted Ming's spirit from the entity, and Nenn, the Master of the Theran Listeners who had also been possessed by Abeloth, committed suicide, significantly weakening Abeloth. Horn then fell unconscious, and Vestara and the Skywalkers were immediately set upon by a group of Sith. Vestara proceeded to eliminate one of the planet's sentient crystals, specifically a tsil, which triggered a major death convulsion. This event further diminished Abeloth's strength and provided Vestara and the Skywalkers with an opportunity to escape the area, taking Horn with them. In the meantime, Gavar's forces had entered orbit and were promptly ambushed by a wing of Jedi StealthX starfighters, which Luke had requested days prior. Upon linking up with the Jedi forces, Luke piloted one of the StealthXs in pursuit of Abeloth, who was fleeing in the meditation sphere known as Ship. The Sith flotilla sustained substantial damage from the Jedi and was compelled to retreat. However, Luke was struck before he could destroy Ship, allowing Abeloth to escape. As Luke recovered from his injuries and the Sith reorganized, Abeloth reached out to the Sith fleet, proposing a partnership aimed at defeating the Jedi.
In 43.5 ABY, a number of Jedi began experiencing a Force psychosis that led them to believe that everyone they knew had been replaced by impostors. Concurrently, Natasi Daala, the Chief of State of the Galactic Alliance, ordered the arrest of Luke Skywalker, the Grand Master of the Jedi Order. Skywalker was subsequently put on trial and exiled for his perceived failure to prevent Darth Caedus' fall to the dark side during the Second Galactic Civil War. Luke then decided to retrace the five-year journey that Caedus had undertaken after the Yuuzhan Vong War, with the aim of understanding the reasons behind his turn to the dark side. Skywalker's son, Ben, accompanied him on this quest.
Eventually, they encountered a strike team from the Lost Tribe of Sith at a space station located in the Maw. They also came across Abeloth, a dark side entity, whom they suspected was the cause of the psychosis. After tracking Vestara Khai, the sole surviving member of the strike team and a Sith apprentice, to the planet Dathomir, they were convinced by the Sith, led by Sarasu Taalon, the High Lord, to form an alliance for a mission aimed at destroying Abeloth. Despite the fact that the alliance was a ploy by the Sith, the Jedi survived the Sith's betrayal and successfully defeated Abeloth. The alliance was briefly reinstated, but after the discovery that Abeloth had not actually died, it once again descended into violence. The Skywalkers, along with Khai, tracked Abeloth to the moon of Pydyr and confronted her again. During the confrontation, Khai killed Taalon, who had begun to transform into another Abeloth-like being, forcing Abeloth to flee once more. Fearing that the Sith would not understand the reasons behind her actions and would perceive it as a betrayal, Khai left the planet with the Skywalkers, who used a blood trail established by Luke to track Abeloth to Nam Chorios.
There, the group met with Taselda, a former Jedi Knight. Luke informed her about Abeloth, and soon after, he learned the technique of mnemotherapy from Taru Durn, the Listener-Master. This technique allowed one to extract and erase memories from another being. As Khai and the Skywalkers continued their search for Abeloth, they were ambushed by Ship, the Sith Meditation Sphere, which was under Abeloth's control. When one of the orbiting Golan III Space Defense NovaGuns fired upon them, it missed and struck a sentient crystal known as a tsil, resulting in a death convulsion in the Force that caused Ship to retreat.
Upon returning to the city of Hweg Shul, they discovered that Abeloth had possessed Nenn, the Master of the Theran Listeners, and had taken control of the Listeners themselves. Vestara sent a concealed message to Gavar, her father, to inform him of the situation, unknowingly playing into Skywalker's plans. He had arranged for a flight of Jedi StealthX starfighters to lie in wait in the system, hoping to lure the Sith there so that the starfighters could ambush them. As Khai and the Skywalkers began investigating Abeloth's possible locations, they were ambushed in the town of Kesla Vein by a Sith party led by Tola Annax, a Sith Saber. After defeating the Sith, the group was contacted by Kandra Nilitz, a journalist, who had brought Valin and Jysella Horn, the psychotic Jedi, to the planet in exchange for the promise of a good story. Luke convinced her to meet with him, but when Khai and the Jedi arrived at Nilitz's airspeeder, they were again ambushed by Sith. After fighting off the Sith and informing the reporter about Abeloth and the Tribe, Khai and the Skywalkers made their way to Crystal Valley to confront Abeloth.
At the Crystal Valley pumping station, they found that Abeloth was draining the Theran Listeners, and that Valin Horn, the psychotic Jedi Knight, had come to Abeloth's assistance. He led them to an illusion created by Abeloth, in the form of Callista Ming, Luke's former lover. Abeloth attempted to appeal to Luke's past feelings for Ming, asking him to join her. However, Luke was able to sense Abeloth's consciousness attempting to hide behind Ming, and Ming pleaded with Luke to save her. He initiated the mnemotherapy technique on Ming while blasterfire erupted outside the cave, as the Sith had arrived and engaged Abeloth in battle there. Horn, believing that the Jedi had brought reinforcements, attacked Ben and Khai. Despite being outnumbered, Horn's superior combat experience allowed him to hold them off. Meanwhile, Luke succeeded in extracting Ming's spirit from Abeloth's control, freeing her and allowing her to pass on into the Force. Abeloth's body then transformed into that of Nenn, the Master of the Theran Listeners, whom she had also consumed. Rather than allowing Abeloth to control him, Nenn chose to end his own life, weakening Abeloth to the point where she could no longer control Horn, who then lost consciousness, and forcing her to flee.
Before Khai and the Jedi could pursue her, however, the group was ambushed by at least two dozen Sith, once again led by Annax. The Sith had them surrounded, and realizing that their demise was imminent, Khai decided to retaliate by killing a tsil. As they fought, she warned the Skywalkers of an impending massive Force attack and began counting down. After ten seconds, she killed the tsil, triggering a tremendous death convulsion that struck the area, causing both Luke and Khai to fall to their knees and stunning the Sith. Khai and the Jedi were the first to recover, and Ben carried the unconscious Horn while Khai assisted Luke in leaving the station. Luke was concerned about her decision to kill a tsil, but Khai reasoned that Luke was the only one capable of defeating Abeloth, and thus, his survival was paramount.
Gavar Khai, now in command of a flotilla of Corporate Sector frigates, had dispatched advance agents to seize control of the planet's orbiting Golan III Space Defense NovaGuns, succeeding in all but one. However, as he arrived in orbit, his fleet was ambushed by the Jedi's StealthXs. Simultaneously, Khai and the Skywalkers emerged from the cave and entered the war zone. After being questioned by Khai, Luke admitted that he had orchestrated the entire scenario, luring the Sith to Nam Chorios to be ambushed by the Jedi. Luke contacted the closest StealthX, piloted by Jaina Solo, and after commandeering Tyria Tainer's, a Jedi Knight, starfighter, he joined the battle. The Sith fleet quickly sustained heavy damage, forcing Khai to order a retreat. Meanwhile, Skywalker pursued Abeloth, who was fleeing in Ship.
Skywalker, whose exile had been revoked following a coup that removed Daala from her office, led Gray Squadron in pursuit of Ship. Raynar Thul of Gold Squadron was struck by one of the NovaGuns and forced to eject from his starfighter, but he managed to detonate a shadow bomb he had launched near Ship. Both Abeloth and Ship were damaged, and Luke seized the opportunity to strike Ship with his laser cannons before being shot down by the NovaGun himself. The remaining StealthXs abandoned their pursuit of Abeloth and focused on drawing fire away from Luke, who was rescued along with Thul.
The Jedi recuperated on the Verity, a supply ship belonging to the Galactic Alliance, where Luke was able to recover in a bacta tank. Despite being injured and severely weakened, Abeloth managed to escape from Nam Chorios in Ship. While the Sith fleet regrouped, Abeloth contacted Gavar Khai, expressing her belief that they could not defeat their common enemy, the Jedi, alone, and proposed an alliance with the Sith. Darish Vol, the Tribe's Grand Lord, then ordered Gavar to bring her back to Kesh, the Tribe's homeworld, to consult with the Tribe's leadership. There, Vol agreed to allow Abeloth to descend to the surface so that they could observe her and decide whether or not to accept her offer of an alliance. However, Abeloth soon launched an attack against the Grand Lord, and when her attempt on his life failed and left her in agony, she destroyed much of Tahv, the capital city, with Force energy. Gavar Khai then severed his ties with the Tribe and led those Sith who chose to remain loyal to Abeloth in a retreat from the world.
Operation Shieldfall was featured in Fate of the Jedi: Conviction, Aaron Allston's third and final novel in the Fate of the Jedi series, and the seventh of nine installments in the series overall. It was released on May 24, 2011.