Battle of Lola Sayu

During the period of the Clone Wars, Jedi Master Even Piell was en route to Coruscant with critical intelligence. This intelligence consisted of the secret hyperspace coordinates for the Nexus Route, intended for the Jedi Council. The information held immense strategic value for both the Republic and the Separatists, as the Nexus Route provided clandestine pathways deep into enemy territory. Suddenly, Piell's fleet found itself attacked by Separatist forces. To protect the data, Piell ordered the ship's computer wiped clean. Simultaneously, he and his Captain, Wilhuff Tarkin, committed half of the information each to memory. Separatist forces boarded Piell's cruiser, reaching the command bridge. Piell personally used the Force to eliminate the initial wave of B2-series super battle droids entering the bridge. However, the arrival of a second wave composed of droidekas prompted the Lannik and his crew to surrender.

Piell, Tarkin, and five clone crewmembers were subsequently imprisoned within the Citadel, a notorious prison facility on the planet Lola Sayu. This prison was renowned for its near-impenetrability and its design specifically to contain and break Jedi. The Citadel's warden, Osi Sobeck, subjected Piell to torture using an interrogation droid and commando droids in an attempt to extract the information from him.

Upon learning of Piell's capture, the Jedi Council initiated plans for his rescue. Plo Koon conducted a briefing to outline the situation. The lack of recent data regarding the Citadel in the archives complicated the formulation of a strategy. The proposed plan involved deploying a rescue team to the planet aboard a stolen Separatist shuttle, creating the illusion of Separatist activity. This team was under the command of generals Obi-Wan Kenobi and Anakin Skywalker, and included Commander Cody, Captain Rex, ARC troopers Echo and Fives, Longshot, Charger, and three additional clone troopers. Furthermore, Skywalker's astromech droid, R2-D2, controlled three reprogrammed B1-series battle droids responsible for piloting the captured Sheathipede-class Type B shuttle designated 81572.

Skywalker's Padawan, Ahsoka Tano, expressed her desire to participate in the mission. However, Skywalker deemed the mission too perilous for her. To bypass the Citadel's lifeform scanners, Skywalker had the entire team frozen in carbonite. During the carbon-freezing process, Tano discussed Anakin's decision with Plo and secretly joined the rescue team. Once all team members were frozen and loaded onto the shuttle, R2 and his droids initiated the engines. Plo observed the shuttle's departure, silently wishing them success.

As the shuttle entered Lola Sayu's orbit, it was detected by the Separatist blockade fleet encircling the planet. The Citadel immediately contacted them, and T-series tactical droid K2-B4, the prison's second-in-command, demanded identification and a description of their cargo. R2-D2 directed his battle droids to respond that the shuttle was carrying supplies and frozen rations. Sobeck, already anticipating a Republic rescue attempt, ordered the shuttle to be scanned for lifeforms. R2-D2 and his droids anxiously awaited the scan's completion. However, no lifeforms were detected, and K2-B4 granted them permission to land on the planet.

The droids landed the ship within a cave near the prison tower and proceeded to thaw out the Jedi and clones. At this point, Kenobi and Skywalker discovered Tano's presence on the strike team. She claimed to have received permission from Master Plo. Skywalker initially expressed anger, but recognizing the impracticality of sending her back, he reluctantly allowed her to remain. While R2-D2, OOM-10, and the other reprogrammed droids stayed with the shuttle, the group commenced their mission. Their initial objective was a secluded entrance in a cliff face. The team was compelled to free-climb due to strong winds rendering jetpacks unusable, and electromines scattered across the cliff made the use of ascension cables too hazardous. Upon reaching the platform, Kenobi, who was leading the way, was forced to drop down when a droid patrol emerged. The droids failed to notice his hand gripping the platform's edge, but sealed the door with a ray shield upon re-entering the prison. This appeared to be a setback, but Tano was able to squeeze into a ventilation duct situated just above the door and deactivate the shield. This duct had been disregarded during the initial planning phase because none of the strike team's intended members could fit inside it.

Meanwhile, Sobeck grew suspicious when a security droid reported the cargo shuttle's failure to arrive, despite having received landing permission. By this time, all members of the rescue team had reached the entrance platform. Clone trooper Charger, being assisted onto the platform by Fives, placed his weight on a fragile foothold that broke, causing him to lose his balance and fall directly into an electromine. The explosion killed him and triggered an alarm. This confirmed Sobeck's suspicions of intruders within the facility, prompting him to activate all security protocols and summon his specialized commando droid units. As the rescue team navigated the prison stealthily, they destroyed several cameras, which activated laser turrets. Kenobi, Tano, and the ARC troopers swiftly destroyed these turrets. However, this action activated an electric field that moved down the hallway towards the group. Most of the team managed to escape into side halls, but trooper Longshot was caught in the field and electrocuted to death.

The team located the cell where Piell was being tortured. The interrogator droid was on the verge of gouging out Piell's last remaining eye when the team entered the cell and destroyed the droids. At this point, Piell revealed that his captain, Tarkin, also possessed a portion of the information. The team proceeded to the cell where Tarkin and Piell's other captured officers were being held. However, Sobeck located the team on the security cameras and surrounded them with his commando droids. The Jedi destroyed the initial wave, but Sobeck activated a magnet in the ceiling, which seized the group's weapons and ensnared Skywalker by his cybernetic right arm. A second wave of commando droids surrounded the group. The Jedi attempted to repel them with the Force, but the droids had magnetized their feet. Despite Sobeck shocking Skywalker, the Jedi managed to overcome the electricity, retrieve his lightsaber from the magnet, and destroy it. This released the group's weapons, enabling them to destroy the droids. This enraged Sobeck, who was further angered by Rex's destruction of the security camera he had been using to observe them. The warden vowed to personally deal with the team. However, the rescue team managed to free Tarkin and the imprisoned clone officers before he arrived.

The Republic team decided to divide into two groups to safeguard the information in case of recapture. Piell, Kenobi, Cody, three clone troopers, and three rescued clones formed one group, while Skywalker, Tano, Tarkin, Rex, Echo, Fives, and the remaining two rescued clones formed the second group. Kenobi's group headed to the upper level to create a diversion, while Skywalker's group escaped the tower through the lower levels. Kenobi's group planted thermal detonators in several hallways on the upper levels, causing explosions that created chaos within the facility. This allowed Skywalker and his group to exit the tower and flee into a series of tunnels. Skywalker then instructed R2-D2 to fly the shuttle to the Citadel's landing platform, so Kenobi's group could be evacuated. Shortly thereafter, K2-B4 informed Sobeck that Count Dooku wished to speak with him. Dooku requested a status report and mentioned hearing about "problems" with the prisoners. Dooku inquired whether his presence was required, but Sobeck assured him that he could manage the situation himself.

Meanwhile, Kenobi's group was hiding within the facility's ventilation shafts, searching for an exit. While climbing a shaft, Cody encountered a probe droid. Piell destroyed the droid before it could escape and reveal their location, but this triggered the closure of security doors within the vents. One clone trooper became trapped and was bisected by a door. Kenobi and Piell were forced to use their lightsabers to cut through the remaining doors. Skywalker's group, in the meantime, traversed the tunnels, with the Jedi General protecting the rear while Tano led from the front. Upon reaching a seeming dead end, the group encountered an impasse and was attacked by commando droids wielding plasma shields. Skywalker, upon arriving, expressed his displeasure and demanded to know why Tano had not breached the wall at the end of the tunnel. This led him to realize that she had not actually received permission to come along. Tano planted explosives on the wall before discovering thermal detonators, which she used to eliminate the commando droids.

R2 and his droid squad landed the shuttle on the platform but were met by K2-B4, who demanded to know the reason for the shuttle's delay. R2's droids acted as if R2 was their prisoner, and K2-B4 ordered him to be taken inside for interrogation. She then reported to Sobeck that the Republic shuttle used to infiltrate the planet had been captured. Sobeck ordered the shuttle to be guarded, intending to lure the Jedi into a trap. Obi-Wan's group observed the shuttle from the shaft but did not see R2 or his droids. Obi-Wan suspected a trap, and the group moved to the other side of the building to gain a better view of the ship. Kenobi attempted to contact Anakin but instead heard Sobeck's voice, who congratulated him on his escape but stated that his next move was easily predictable. The group was then surrounded by crab droids, droidekas, and commando droids, forcing them to surrender. Anakin's group, meanwhile, entered a large fuel pipeline to reach the rendezvous point, where R2 would pick them up after evacuating Obi-Wan's group.

Piell, Kenobi, and the rest of their group were brought before Sobeck, who demanded Piell's half of the information and threatened to execute his men if he refused. Piell responded that in times of war, everyone was prepared to die to protect such information. Unimpressed, Sobeck executed a trooper. When Piell remained silent, Sobeck prepared to execute another. However, K2-B4 informed him that Anakin's group had been located and that droids were closing in on them. Sobeck ordered the prisoners to be taken to the interrogation level for torture, while he oversaw the capture of the second group. R2 and his droids realized that Kenobi's group had been captured and managed to deceive the security droids escorting them into handing over the prisoners. Ahsoka found a way out of the pipeline and searched for the shuttle but could not locate it. The group was ambushed by droids. After exiting the pipeline, Skywalker threw a thermal detonator into it, creating a large explosion that destroyed their attackers. Realizing that something was wrong, as the shuttle had not arrived, Anakin led the group to the Citadel's landing platforms. With the droid squad intended to capture Anakin's group gone, Sobeck and K2-B4 attempted to determine the group's location. A droid then reported to Sobeck that the prisoners had not arrived at the interrogation level. K2-B4 informed Sobeck that Count Dooku insisted on speaking with him, but Sobeck ignored it, correctly predicting that both groups would head for the airfield to steal a ship, as it was their only means of escaping the planet.

Kenobi's group, escorted by R2 and his droids, attempted to deceive the droids guarding their shuttle by claiming they had orders to move the prisoners to another location. However, K2-B4 informed the guards that the prisoners were attempting to escape with reprogrammed battle droids. This led to a battle on the landing platform between the group and Sobeck's droids. Anakin's group soon joined the fight and eliminated the droids manning the defense turrets. Three droids on STAPs attacked the group. Piell destroyed the first, while Skywalker hijacked the second. Piell jumped onto Skywalker's back to deflect shots from the third and destroy it. The group destroyed several waves of droids but could not board the shuttle and escape, fearing its destruction. A group of commando droids with plasma shields entered the platform. Echo and Fives used a thermal detonator to blow them up, but one survived and manned a defense turret to destroy the shuttle. Anakin attempted to shoot it with his stolen STAP, but the droid shot the STAP down. Echo took a plasma shield from a fallen droid and attempted to secure the shuttle. However, the droid managed to hit the shuttle, destroying it and "killing" Echo. With the shuttle gone, the group retreated into the lower caverns.

The team was unaware that Echo had survived. He was discovered by the Separatists, who recognized his value to the Confederacy due to his status as a clone trooper. He was captured and subjected to experimentation by the Separatists.

With their shuttle destroyed, the group contacted the Jedi Council to inform them of the situation. The council dispatched a fleet led by masters Plo Koon, Saesee Tiin, Adi Gallia, and Kit Fisto to attempt a rescue. Meanwhile, the group had to traverse the challenging terrain of Lola Sayu. Later, upon contacting the council again, Yoda provided them with the rendezvous point: a small island. After the transmission, the group was attacked by a few commando droids. One was shot, and Fives used a grenade to destroy the others. Kenobi remarked that these would not be the last droids they would encounter.

Sobeck tasked K2-B4 with commanding the blockade fleet, anticipating that the Republic would launch a second mission to evacuate the prisoners. He focused on recapturing the team. Dooku contacted him again, expressing anger that Sobeck had been avoiding his transmissions. He once again asked if he had recaptured the prisoners, and Sobeck replied that this was not the case, but his troops would soon capture them. Dooku told him that his honesty was the only thing keeping him alive. The group, meanwhile, had to climb down a cliff to continue their journey. Unfortunately, another squad of droids attacked them. The group used cables to climb down, and Anakin ordered R2-D2 to have his droids hold off the enemy. OOM-10 and the other reprogrammed droids fought Sobeck's troops but were quickly overwhelmed and destroyed. A commando droid shot a climbing cable, causing two clones to fall to their deaths. The others made it down and fled into a cave, while Anakin and Cody covered their retreat.

Sobeck released a pack of anoobas, creatures capable of tracking the team by scent. The group heard the creatures howling as they approached and realized that the anoobas would lead the droids directly to them. Anakin and Obi-Wan volunteered to lure the creatures away while Piell led the group. Skywalker and Kenobi fought off the anoobas, killing at least three of them with their lightsabers. The rest of the group was attacked by crab droids and droids on STAPs. A crab droid killed a clone. Piell and Ahsoka ordered the group to continue while they dealt with the crab droids. The others, however, had to fight off the STAP squad. A clone navigation officer sacrificed himself to save Tarkin from STAP fire, and Tarkin responded by shooting down the droid responsible. A droid on a STAP attempted to shoot Kenobi, but the Jedi destroyed him with his lightsaber. An anooba then lunged at him from behind, but Kenobi kicked the creature into a lava stream. Piell and Tano eliminated the crab droids, but while Piell finished off the last one, a remaining anooba attacked him by surprise and mauled him, fatally wounding him. Ahsoka dealt with the creature before tending to the dying Piell. She wanted to get help, but Piell urged her to stay and gave her his half of the information. He ordered her to ensure that only the Jedi Council received it, before passing away. The group had just destroyed the last STAPs when Ahsoka arrived with Piell's body. The group paused to honor Piell and cremated his body in the lava before moving on.

The Republic rescue fleet emerged from hyperspace and approached the planet, engaging the Lola Sayu defense fleet. Tiin, Gallia, and Fisto commanded squadrons of ARC-170 starfighters in their personal starfighters to break through the blockade for Koon, who would attempt to land on the planet with a gunship to evacuate the team.

Meanwhile, Sobeck learned that the anoobas had located the prisoners and went with a squad of commando droids on STAPs to deal with them personally. The group had reached the island serving as the rendezvous point for the rescue fleet. The group now consisted only of Skywalker, Kenobi, Tano, Tarkin, Rex, Cody, Fives, R2-D2, and two rescued clones. Sobeck's squad arrived and engaged them. Anakin and Obi-Wan both hijacked a STAP and destroyed most of the droids. Sobeck opened fire on the group, but R2-D2 created a cloud of smoke, blinding the warden and allowing Fives to shoot his STAP down. Sobeck fell onto the island. Tarkin attempted to shoot him but missed. An enraged Sobeck lifted the captain. Realizing he could never obtain the information from Tarkin, Sobeck prepared to throw him into the lava to ensure that no one would have it. Ahsoka spotted Sobeck and impaled him through the back with one of her lightsabers, killing him and saving Tarkin. Plo Koon's gunship, escorted by Tiin, Gallia, and Fisto, exploited a gap in the Separatist defenses and reached the planet. They arrived just in time to retrieve the surviving members of the team as a squad of crab droids overwhelmed the island. Koon ordered Admiral Barton Coburn to recall all starfighters. After they returned to the command ship, the Republic fleet retreated to Coruscant.

Upon arriving on Coruscant, the survivors met with Yoda and Mace Windu on the Jedi temple landing platform, who expressed their sorrow over Piell's death. Yoda wished to speak with Tarkin and Ahsoka, who held both halves of the information. However, Tarkin revealed that he had orders from Supreme Chancellor Palpatine to deliver his portion of the information directly to him, while Ahsoka had promised Piell to share her information with only the Jedi Council. Yoda then decided to personally discuss the best solution to this issue with Palpatine. Before departing, Tarkin expressed his respect for Skywalker and wished there were more Jedi like him. After he left, Kenobi voiced his doubts about Tarkin and told Skywalker that the Jedi should never abandon their principles, even during times of war.

Echo's survival remained unknown until much later, during the Battle of Anaxes. He had been sold to the Techno Union, who kept him in a stasis chamber and extracted a battle strategy algorithm he had developed with Rex and Fives from his brain. When the algorithm was used against the Republic on Anaxes, Rex realized the Separatists had it somehow and deduced that Echo must not have been immediately killed in the blast. He reasoned that he and Fives were the only people besides Rex to know of the algorithm, and Fives' later death was definitively confirmed. Rex was able to confirm that Echo was alive after infiltrating a Separatist Cyber Center alongside Clone Force 99, the "Bad Batch," and intercepting a transmission of his voice. Echo was eventually rescued from Skako Minor by Rex, Skywalker, and the Bad Batch, later accepting an offer to join the squad after helping defeat the Separatists at Anaxes.

Echo recognized Tarkin, who had been promoted to Admiral, from the battle. He identified him to his squad-mates when the officer came to Kamino to evaluate clones in the aftermath of Order 66 and the proclamation of the Galactic Empire, noting that he had not liked clones.

The Battle of Lola Sayu was initially depicted in a three-episode story arc near the end of the third season of Star Wars: The Clone Wars. These episodes were entitled "The Citadel," "Counterattack," and "Citadel Rescue."