The Clash at the World-Well unfolded in 27 ABY at the Well of the World Brain, situated on Yuuzhan Vong-controlled Coruscant. Jedi figures Jacen Solo and Ganner Rhysode were escorted to the Well by a force numbering in the thousands of Yuuzhan Vong warriors. The intention was for Solo, who had feigned conversion to the Yuuzhan Vong religion during his captivity, to offer Rhysode as a sacrifice.
However, Rhysode embraced his deep-seated aspiration to be a heroic figure, transforming it into a source of immense power. He confronted the massive Yuuzhan Vong force at the Well's entrance, providing Solo the opportunity to communicate with the World Brain and sway it to his cause. Rhysode initially battled the warriors individually, but as his invincibility became apparent, they attacked in greater numbers. Rhysode achieved complete oneness with the Force, vanquishing every warrior who dared to oppose him, thus buying Solo crucial time. Ultimately, facing a tank beast and accompanying infantry, Rhysode brought the ceiling crashing down, resulting in his own death alongside his adversaries. Solo managed to escape with his mentor Vergere's assistance, eventually making his way back to the New Republic.
Rhysode's extraordinary demonstration of skill and might garnered him considerable respect within the Yuuzhan Vong warrior ranks. It also secured him a place in the Jeedai heresy and entry into the Yuuzhan Vong religious pantheon. Solo's success in converting the World Brain and his subsequent return to the New Republic proved pivotal in the eventual defeat of the Yuuzhan Vong and the recapture of Coruscant.
During the Mission to Myrkr, the Yuuzhan Vong took Jacen Solo prisoner. He spent the following months with Vergere, a former Old Republic Jedi who concealed her abilities while among the Yuuzhan Vong. He was subjected to torture and exposed to Vergere's radical philosophy concerning the Force. Solo eventually escaped to Coruscant, which the Yuuzhan Vong had conquered. There, Vergere and Executor Nom Anor recaptured him. They offered him the chance to embrace the Yuuzhan Vong religion and assume the mantle of godhood, as the Yuuzhan Vong believed him to be the embodiment of Yun-Yuuzhan. Solo accepted the offer.
As one of the Twin Gods, the Yuuzhan Vong also regarded his twin sister, Jaina Solo, as the incarnation of Yun-Harla. They were eager for the twins to engage in a fatal duel, a traditional Yuuzhan Vong practice. Consequently, they sought to capture Jaina. To draw Jaina to Coruscant, they disseminated rumors about an individual who had spotted Solo on the terraformed planet. However, these rumors directed people to Jacen Solo himself, disguised as a middle-aged man. As the rumors gradually spread, the hope was that Jaina would hear the message and be compelled to seek out this individual. Jacen, in his disguise, was placed aboard a camp ship with several Yuuzhan Vong guards and a dovin basal that would obliterate the ship and its refugees if he betrayed them. Jacen Solo, however, had not genuinely converted and was determined to sabotage the attempt. Jedi Knight Ganner Rhysode heard the rumors and pursued them, leading him to the camp ship. Sensing Rhysode's approach, Solo enveloped him with a Force-induced sense of dread and foreboding, hoping to deter him from the trap. Rhysode remained undeterred. Even after a potent mind trick, he returned, overpowered the guards, and confronted the disguised Solo. Rhysode demanded that he be told what the seemingly unknown man knew of Jacen Solo. Solo revealed his true identity, stunned Rhysode, and brought the captured Jedi back to Coruscant, deeming the trap a failure.
Rhysode was kept in a semi-conscious state on Coruscant while Solo convinced Anor to allow him to sacrifice Rhysode as practice for the twin sacrifice. This was to take place in the Well of the World Brain, formerly the Senate Building. Anor agreed, but Solo's true aim was to gain access to the World Brain itself. Once the trial sacrifice was fully prepared, Rhysode was awakened and left alone with Solo, so that Solo could convert him to the Yuuzhan Vong religion as well. Solo began with a conventional religious address, but quickly rendered the monitoring creatures in the room unconscious. He told the incredulous and confused Rhysode that he remained a Jedi at heart and tended to Rhysode's injuries. He convinced Rhysode to accompany him, arguing that they were both as good as dead, but that within the Well of the World Brain they could achieve something meaningful with their deaths. He offered Rhysode Anakin Solo's lightsaber and persuaded Rhysode to cooperate as they were led to the sacrifice.
Anor, a cynic himself, was reluctant to trust Solo's conversion but went along with it nonetheless. Anor and Master Shaper Ch'Gang Hool led the two Jedi in a grand procession to the Well of the World Brain. Vergere, with whom Solo had shared his plans, was also present; she was his mentor and, he suspected, no more loyal to the Yuuzhan Vong than he was. Rhysode was confused and terrified, but Solo remained remarkably calm. Just before entering, Rhysode collapsed, unable to endure the situation any longer. Overwhelmed with self-loathing at his perceived weakness, he nearly took his own life. Solo had to lift him with the Force and use telekinesis to force him to walk. As soon as they entered the Atrium of the Senate, Solo slammed the door shut, locking himself and Rhysode inside. They hurried to the Well of the World Brain, the former Grand Convocation Chamber, where Solo offered Rhysode an escape route. Rhysode refused to leave without Solo, and as they argued, the Yuuzhan Vong breached the door. Rhysode finally accepted his fear and his lifelong desire to be a hero, deciding to make a stand at the door while Solo communed with the World Brain.
Rhysode defeated the squad of warriors that Anor sent in to investigate the area and strode to the door, where he dramatically challenged the thousands of Yuuzhan Vong warriors present in the procession. Anor was unnerved by Rhysode's extreme confidence and urged the warriors to attack.
The warriors initially engaged Rhysode one-on-one, as they did not perceive him as a significant threat and considered single combat the most honorable way to engage an enemy. However, he defeated all who came at him. After a series of single engagements, the warriors began attacking in pairs, as Rhysode had proven too formidable for single combat. Rhysode remained undefeated, immersing himself completely in the Force and shrugging off numerous minor injuries as he cut down warrior after warrior. Eventually, the Yuuzhan Vong attacked him in groups, but by that time Rhysode had already created heaps of dead bodies around himself.
Anor, taking cover behind some debris, was terrified of Rhysode and of the fact that Jacen Solo was alone with the World Brain. He demanded that the commander of the warriors use some sort of explosive or gas against Rhysode. The commander refused, citing that it would be a breach of honor to deny such a worthy enemy personal combat. Hool also suggested that the use of area-effect weapons would be unwise, as they could harm the World Brain. Vergere drew Anor aside and told him that Warmaster Tsavong Lah would not tolerate Anor's role in the fiasco. She knew that he kept a secret craft in an otherwise unknown escape route inside the Well of the World Brain, and encouraged him to flee and take her with him. Anor waited until he was unobserved, then sneaked in through a hidden entrance, taking Vergere with him to the craft and preparing it for launch. Vergere betrayed him, however, revealing that she was a Force-user and binding him as she awaited Solo.
Rhysode continued battling, holding off massive numbers of Yuuzhan Vong as he sustained various injuries and suffered venomous amphistaff bites. He became one with the Force and, repeating his battle cry of "None shall pass," he used his skills in telekinesis to levitate the pieces of the Great Door of the Senate and tear the statues lining the Atrium from their pedestals, battering his enemies with whirling debris. In time, he killed all those who faced him. Pausing, he saw that the Yuuzhan Vong had brought forth reinforcements—infantry supporting a massive flame- and acid-spewing tank beast. Realizing he could not hold out against it, Rhysode collapsed the ceiling of that part of the building on himself, the tank beast, and the infantry, killing himself and his enemies and blocking the entrance to protect Solo.
Meanwhile, the World Brain's mass of tentacles drew Solo into the nutrient pool that sustained it. Solo had befriended the World Brain earlier in his captivity, before attempting to kill it. The betrayed creature wanted to take revenge and devour Solo. However, Solo opened himself to the World Brain through the Force in a bond of perfect empathy and love, establishing their oneness. Solo persuaded the World Brain to subtly disrupt the worldshaping ongoing on Coruscant, just enough to irritate the Yuuzhan Vong and prevent their world from achieving perfection—in Solo's words, to force the fanatics to learn to compromise. Upon realizing that Rhysode was still fighting, Solo left the pool to rush to his aid, but Vergere was present and persuaded him to let Rhysode have his great moment and to honor his sacrifice by escaping. Solo felt Rhysode die as Vergere took him to Anor's escape ship, and the pair departed Coruscant to return to the New Republic.
Solo and Vergere successfully escaped, returning to the New Republic. There, Vergere prevented the deployment of the Alpha Red bioweapon and sacrificed her life to save Solo. Solo went on to help end the war peacefully, persuading Zonama Sekot to ally with the Jedi, which helped the Shamed Ones rise up against the Yuuzhan Vong. He also killed Onimi, the power behind the Yuuzhan Vong throne. His rapport with the World Brain also allowed him to prevent the World Brain from destroying Coruscant when the Galactic Alliance recaptured it.
Several Yuuzhan Vong survivors witnessed Rhysode's last stand, and his display of martial strength and bravery earned him awe and respect among the warrior caste. Rhysode also entered the pantheon of the Jeedai heresy, a creed among the oppressed Shamed Ones of the Yuuzhan Vong that revered the Jedi as heroes who would liberate them from their low social standing and restore true religion to the Yuuzhan Vong. Rhysode, called "the Ganner," was revered as one of these Jedi heroes. According to a vision Vergere had, "the Ganner" would eventually enter the Yuuzhan Vong religion as an invincible Jedi giant who guarded the gates to the land of the dead, his battle cry of "None shall pass" inscribed in the arch, keeping the dead within where they could not bother the living.
The Clash at the World-Well is featured in Matthew Stover's novel The New Jedi Order: Traitor. The first and only explicit naming of it as "the battle of the World-Well" is in The New Jedi Order: Destiny's Way. Although Rhysode's death was likely unplanned during the writing of The New Jedi Order: Dark Tide I: Onslaught, it contains imagery that could be retroactively interpreted as foreshadowing the battle: Corran Horn has a brief mental vision of Rhysode covered in swarming Yuuzhan Vong.
The Clash at the World-Well has gained immense popularity among readers due to its epic scale. It was included in Star Wars Insider's list of the 20 Most Memorable Moments of the Expanded Universe and topped fan polls of the greatest moments in the Expanded Universe.
"The Final Order," a short story by Seth Dickinson in the 2020 anthology book From a Certain Point of View: The Empire Strikes Back, features the Imperial officer Canonhaus recalling an episode of a program called Laser Masters, specifically a scene where a Laser Master defended the Senate chamber from a monstrous army with the phrase "None shall pass." Canonhaus recalls the episode in a haze, as though it originated from another reality, and reflects on the heroism shown by the Laser Master and repeats the phrase several times in his final moments.