Pandemonium is set in 2975 BBY and occurs twenty-five years after the events of Pantheon and Secrets. The novella is told from the points-of-view of three main characters: the Alanciari Keshiri woman Quarra Thayn, the Sith Lord Edell Vrai, and Grand Lord Varner Hilts. Following an unsuccessful attempt to drive the Lost Tribe of Sith from Kesh in 4975 BBY, Adari Vaal and three hundred other Keshiri followers had fled from Keshtah Minor to another continent known as Alanciar. There, they transformed the Keshiri civilization and prepared it to resist a future Sith invasion. Centuries later in 2975 BBY, Grand Lord Varner Hilts succeeds in reuniting the Lost Tribe following nine-hundred years of civil war. He has committed the Tribe to finding a way to reach Alanciar. After much difficulty, a Sith mathematician named Edell Vrai succeeded in constructing a fleet of airships which allowed the Tribe to travel to Alanciar.
The story begins at Point Defiance, a naval fort on Garrow's Neck, a mountain peninsula on the south-western coast of Alanciar. It was part of a canal-crossed region known as the Shank which terminated into six mountain peninsulas. The first protagonist was Quarra Thayn, an Alanciari woman who is the Chief military administrator and wardmaster of Uhrar. While Thayn was a married mother of three children, she was secretly having an affair with a soldier in the Alanciari military named Jogan Halder. While officially on a tour of the battle-armor factories on the Northern Slope of Alanciar, she visited Port Defiance which was where her lover is stationed. The Alanciari Keshiri were a militaristic society which was structured around resisting an invasion by the Lost Tribe of Sith from Keshtah Minor. The continent was heavily fortified on land and sea. Thayn and Halder were dissatisfied with their family commitments and the militaristic rigours of Alanciari society. Therefore, they sought relief and solace in romance.
Meanwhile, the second protagonist Edell Vrai, a High Lord and Chief Engineer of the Tribe, was leading a vanguard force consisting of three Sith airships: the Candra, Lillia, and the Dann Itra. These airships were powered by helium gasbags and were guided by uvaks. Edell had planned an over flight reconnaissance of "Keshtah Major" (the Sith name for Alanciar) which would have been followed by a return trip across the Southern Ocean to the western coast of Keshtah Minor, the domain of the Lost Tribe. The fleet approached the Shank but were quickly attacked by black javelins fired from Alanciari ballista emplacements on Point Vigilance. The Lillia and Dann Itra were destroyed.
This incident marked the first contact between the Lost Tribe and the Alanciari Keshiri. The Alanciari defenders were able to light the fireglobes and warn the rest of their people of the invaders. Quarra and Jogan were present when the Alanciar anti-air defenses assaulted the Sith fleet. Quarra panicked because she did not want her husband to discover her affair with Jogan since she was far away from the Northern Slope, which she was supposedly visiting. However, Quarra was unable to escape since her muntok, a six-legged reptilian steed, had escaped during the fighting.
Meanwhile, Edell's airship Candra managed to travel further inland but was assaulted by the Alanciari air force which also consisted of uvak riders. The Candra was eventually brought down with the loss of much of its crew. However, Edell and four of his crew (Peppin, Ulbrick, Janns, and the Keshiri scholar Tellpah) survived and managed to land on Alanciar. One of the uvaks known as Starboard tethered to the Candra was killed during the fighting and crashed on top of Jogan, seriously wounding him. This accident brought the story's two main protagonists together.
Quarra attempted to protect her lover and fend off the Sith. Despite her Force-sensitivity, she was overpowered following a struggle with Edell. Quarra surprised her captives by revealing that the Alanciari Keshiri spoke Galactic Basic Standard, the same language that the Lost Tribe spoke. Quarra managed to convince her captors to spare Jogan's life. By then, Edell had been joined to two other Sith. Quarra and Jogan were subsequently taken prisoner by Edell and his men.
Back in Tahv, Grand Lord Varner Hilts and his wife Iliana Hilts are present during a meeting with High Lord Korsin Bentado, the designated military commander of the Lost Tribe's invasion fleet that would invade Alanciar after Edell had made contact with the continent. The Sith leadership had received this new through thoughtcriers, individuals capable of transmitting information through the Force. While the Hilts wanted to wait until Edell had returned, Korsin was eager to go to war. This invasion force was known as the Ebon Fleet and consisted of sixty airships; making it twenty-times the size of Edell's scouting party. This party included several Keshiri translators and many of Korsin's supporters from the former Korsinite League. Despite their reservations, Varner and Iliana gave their approval for Korsin to launch the invasion since they secretly hoped to eliminate a political rival.
Meanwhile, Edell and his Sith followers managed to seize control of the Keshiri sailing ship Mischance after a fierce battle with the crew. The Mischance was a fishing vessel used for trapping crustaceans. They managed to escape into open water before reinforcements from Garrow's Neck could capture them. Jogan and Quarra were tied up to the ship's mast. Eventually, Edell managed to coerce Quarra into serving as his guide for a reconnaissance mission into Alanciar's military capital Sus'mintri. In return, Quarra managed to convince Edell to untie Jogan and give him medical treatment. Edell agreed but stated that they had to return by two weeks or she would never see her lover again. While Quarra appeared to collaborate with the invaders, she secretly intended to scare the Sith "back to where they came from."
Edell and Quarra managed to infiltrate Garrow's Neck using a small cove that was not guarded by Alanciari troops. After four days of traveling, they reached the town of Kerebba disguised as performers for Observance Day, an annual festival which commemorated the arrival of the Keshiri woman Adari Vaal, who had fled the Lost Tribe-controlled Keshtah Minor. The festival was intended to promote a sense of patriotism among the Alanciari Keshiri and to continually remind them of the threat posed by the Lost Tribe. Edell acted as a Sith "villain" but was angered by the anti-Sith undertones of the festival. Following the festivities, the pair slept in a dry culvert near the Kerebba canal station. That night, Quarra experienced a Force vision where she encountered the former Sith woman Orielle Kitai and her Jedi husband Jelph Marrian who gave her encouragement. Orielle compared her former life as a high-ranking member of the Sith tribe to Quarra's station in the Alanciar military. She also warned Quarra of the dangers of "living within a dream." Convinced of the inevitable Sith take-over and intrigued by Orielle's peaceful life in the jungle, Quarra decided to remain loyal to her family rather than becoming the consort of Edell Vrai after the Sith have occupied in Alanciar.
During their time together, Edell and Quarra developed a reluctant friendship. Edell learnt about Quarra's family life and her affair with Jogan. They also discussed cultural differences between the Keshiri on Keshtah Minor and Alanciar; with the latter being more suited to building practical implements like aqueducts than the former. The pair eventually reached the Western Shield that afternoon and Sus'mintri was only about two days away. At that point, Bentado's Ebon Fleet led by his flagship the Yaru arrived over the countryside but were quickly shot down by the Alanciari air defenses. The fleet was quickly decimated but a several Sith managed to survive the landing. They were immediately hunted by the Alanciari military. Edell was furious with Bentado for attacking too early without waiting for him to return to Keshtah Minor.
Edell and Quarra were quickly caught-up in the fighting when the surviving Sith landed on the ground. Quarra personally killed a Sith warrior but spared Edell, citing her agreement with him. However, she did a detour to her hometown of Uhrar to check that her three children were safe. After finding that her three children were safe in the town's shelter, she rejoined Edell and the two continued their journey to Sus'mintri. Using her Force abilities, Quarra secretly managed to send a telepathic message to the War Cabinet in Sus'mintri telling them that she had a Sith Lord with her. The War Cabinet instructed Quarra to bring Edell to them stating that they knew what to do. Quarra was determined to save Jogan and be a heroine for her people.
Edell and Quarra eventually reached Sus'mintri, the capital of Alanciari civilization. The Alanciari War Cabinet was housed within a one-storey hall known as Vaal Hall which was situated next to a tall silo tower that was capable of relaying communications between the different regions of Alanciar. Quarra and Edell were allowed to enter the building by a lone Keshiri sentry. They quickly discovered that Bentado and the survivors of the Ebon Fleet had regrouped and infiltrated Vaal Hall and slaughtered the entire Alanciari War Cabinet along with all the bureaucrats and guards present. Due to the centralized nature of the Alanciari government, the various military, industrial and education directorates were based in one building. This made it easy for an enemy force to decapitate the leadership. This development destroyed Quarra's plans to lure Edell into a trap and to save Jogan.
Edell and Quarra also encountered Lord Bentado and the surviving crew from the Ebon Fleet. Also present was Bentado's Keshiri assistant Squab. Bentado explained to the protagonists that Sus'mintri contained thirteen communications facilities including the tall silo tower, which was a signalling station that was used for transmitting and processing telepathic messages from Force-users. They managed to infiltrate Vaal Hall and slay the Alanciari War Cabinet. Bentado and his men were then able to use telepathic messages to draw the other survivors towards the building. Unknown to the Alanciari military forces scattered across the continent, an enemy force had infiltrated and hijacked the very hub of their government. The Sith continued to use the signal tower to relay instructions to the Alanciari artillery defenses.
Having decapitated the Alanciari government, Bentado then put his next plan into action: destroying the remaining sixteen ships of the Lost Tribe which were traveling towards Alanciar. Bentado had intended to kill Grand Lord Hilts and also create a second Tribe on Alanciar. He planned to use the militaristic Alanciari Keshiri and their industrial base to forge a new rival empire. Edell countered that Bentado's plans would not work since his followers would eventually get tired of having to hide inside the building in order to avoid being discovered by the Alanciari Keshiri. Meanwhile, Quarra condemned Bentado for killing the Alanciari leadership and vowed that her people would eventually come looking for them. In the end, Edell refused to support Bentado's plans and attempted to order him to work with Grand Lord Hilts until reinforcements arrived.
Bentado ordered his men to seize Edell and Quarra but the two managed to escape their pursuers. When Quarra wanted to escape Sus'mintri and return to the Mischance in order to rescued Jogan, Edell revealed that the Mischance had received orders to sail to Keshtah Minor. Despite their differences, the two agreed to work together to survive and managed to hide for a day within Adari Vaal's secret library. During this period, Quarra discovered Adari Vaal's personal memoirs which revealed that she had succumbed to weakness during an encounter with Yaru Korsin, the founder of the Tribe. Quarra and Edell then decided to disrupt Bentado's communications by taking out the High Lord himself. Quarra also found Adari's lightsaber in the archive.
Meanwhile, Grand Lord Hilts' airship arrived off the western coast of Alanciar near Port Melephos. In response, Bentado had instructed Squab to order the Keshiri uvak "diamond-flak" teams to engage the aircraft. Edell and Quarra managed to enter Bentado's "worldwatch" room through a diagonal tunnel leading upwards from the archive. Upon exiting, Edell engaged Bentado in a lightsaber duel while Quarra fought off his bodyguards. However, they were unable to stop Squab from escaping to the tower to relay Bentado's commands. Bentado eventually managed to overpower both Edell and Quarra with his Force powers. Squab also retrieved Quarra's lightsaber and revealed that Grand Lord Hilt's airship had safely landed at Port Melephos.
In reality, Squab was secretly serving Grand Lord Hilts and had disobeyed Bentado's command to down the Grand Lord's airship. Bentado then attempted to carry on with his plan by ordering Squab to order the Alanciari troops to kill Hilts and anyone with him. However, Squab countermanded that order with a new order from Hilts ordering him to kill Bentado. Squab then used Quarra's lightsaber to stab Lord Bentado through the heart, killing the Sith Lord. This effectively ended Bentado's dreams of creating a Second Tribe and killing his rival Hilts. Squab then handed Bentado's weapons to Edell Vrai, who was designated as the new commander of the Sith forces on Alanciar. Edell then used the Force to reassert control over Bentado's men and the signaling devices.
Grand Lord Varner Hilt's white airship Good Omen arrived at Sus'mintri after doing a brief stop-over at Port Melephos. The Good Omen encountered no resistance on both occasions because the Sith had used the Alanciari Keshiri Jogan Halder to greet the Alanciari population. Edell and Quarra were both present when Hilts' airship arrived at Sus'mintri where it was welcomed by thousands of Keshiri. Following his arrival in Sus'mintri, Jogan gave a speech where he explained that he had been taken to Keshtah Minor by ship. They eventually reached Tahv where he was greeted by the Keshtah Alanciari who successfully convinced him that the Lost Tribe were actually the benign Protectors and that the Keshiri were actually happy to live under the Sith. Jogan also told them that Bentado and the Ebon Fleet were the malevolent Destructors who had been expelled from Keshtah. He also explained that Edell Vrai and his airships was a "trusted friend" of the Protectors who was pursuing the Destructors.
The Tribe in reality had tricked and coerced Jogan into distorting the events of the Sith invasion in order to win the "hearts and minds" of the Alanciari. This ploy worked and Jogan was welcomed as the new "Herald." Jogan was immediately followed by Grand Lord Hilts, who was disguised as the Bright Tuash, a legendary Keshiri deity. He claimed that Adari Vaal, the revered founder of Alanciari civilization, was his daughter and that she was well-meaning but misguided. He backed Jogan's account and professed to be saddened that the Destructors had attacked and killed the Alanciari leadership. He also assured the Alanciari that the Destructors and their leader had been defeated by his agent Edell Vrai and the Alanciari woman Quarra. To facilitate peace between the two continents, the "Bright Tuash" decreed that both Human and Keshiri relief workers would arrive from Keshtah over the next few days to promote reconciliation and unity.
Grand Lord Hilt's deception worked and the Alanciari Keshiri willingly submitted to Sith rule. Jogan's message was transmitted across the entire continent. In private, Varner confided in Edell that he had been able to manipulate the similar histories of the Alanciari and Keshtah Keshiri to orchestrate this grand deception. He also explained that the Tribe had withdrawn from public view when Jogan visited Tahv while putting their most loyal Keshiri on the streets. Hilts regarded bringing the Alanciari Keshiri willingly into the Sith's service as a greater victory than capturing new slaves in combat. Edell was subsequently appointed as the new de-facto governor of Alanciar. As part of the reunification process, the Alanciari Keshiri publicly destroyed their balliste. New plays focusing on Jogan were also commissioned to replace the patriotic plays associated with Observance Day.
Finally, Quarra attempted to warn the Alanciari of the deceptive nature of the Sith take-over but no one was willing to listen. Instead she resolved to accept her destiny and guide her compatriots through the process of "Unification." She also returned to her husband Brue Thayn and her three children.
- In chapter six, it is said that Iliana Hilts cut off Korsin Bentado's left hand "half a century earlier", which would mean it happened fifty years ago. However, it should say a quarter of a century, as Pandemonium occurs 25 years after Lost Tribe of the Sith: Pantheon and Lost Tribe of the Sith: Secrets, during which, in one of the two, Korsin loses his hand to Iliana. This is most definitely an error, as, in addition to a multitude of other errors this causes, it would mean Iliana wouldn't even be born yet, as she is said, earlier in the same chapter, to be forty-nine.