Battle of Lola Sayu During the Clone Wars , a battle was fought between the Grand Army of the Republic and the Confederacy of Independent Systems in and around the Citadel , a Separatist prison on Lola Sayu . During the battle , Jedi and clone trooper s led a rescue of Jedi Master Even Piell , Captain Wilhuff Tarkin , and their clone forces ; Piell and Tarkin had discovered the coordinates of the hyperspace lane known as the Nexus Route , which they believed could prove vital to the Republic ' s war effort . Though Piell was killed , Tarkin and his forces were rescued and brought the information to the Galactic Republic . Prelude . Capture of Even Piell . Returning from a mission , Jedi Master Even Piell was on his way to Coruscant in order to deliver valuable information about secret hyperspace coordinates known as the Nexus Route to the Jedi Council . This information could prove vital for both the Republic and the Separatists , as the Nexus Route included secret ways to reach deep enemy territory . Piell ' s fleet was suddenly attacked by Separatist forces . To secure the information , Piell had the ship ' s computer erased , while he and his Captain , Wilhuff Tarkin , both memorized half of the data . The enemy boarded Piell ' s cruiser and made it to the command bridge . Piell himself destroyed a first wave of B2 super battle droid s that entered the bridge by using the Force , but when a second wave consisting of droideka s entered the bridge , the Lannik and his crew chose to surrender . Piell , Tarkin and five clone crewmembers were imprisoned in the Citadel , an infamous prison on the planet Lola Sayu , that was known to be almost inescapable and designed to hold and break Jedi . The Citadel ' s warden , Osi Sobeck , had Piell torture d by an interrogation droid and some commando droids to get the information out of him . Rescue plans . When the Jedi Council learned of Piell ' s capture , they made plans to rescue him . Plo Koon held a briefing about the situation . Since the archives did not contain any recent data about the Citadel , it would be difficult to form a plan . The plan would be to get a rescue team on the planet by using a stolen Separatist shuttle to make the enemy think they were Separatists . The team would be led by generals Obi - Wan Kenobi and Anakin Skywalker and consisted of commander Cody , Captain Rex , ARC troopers Echo and Fives , Longshot , Charger and three other clone trooper s . Additionally , Skywalker ' s astromech droid , R2 - D2 , had three reprogrammed B1 battle droid s under his command , that would pilot the shuttle . Skywalker ' s padawan , Ahsoka Tano wanted to join the team , but Anakin didn ' t allow this as he thought this mission would be too dangerous for her . A final problem would be to pass the Citadel ' s life form scanners undetected . Anakin suggested to have the team frozen in carbonite , as this would fool the scanners . While the team was frozen in carbonite , Ahsoka discussed Anakin ' s refusal to let her come along with Plo Koon and secretly joined the rescue team . Once all frozen teammembers were loaded onboard the shuttle , R2 and his droids started the engine , with Koon watching the shuttle take off and silently wishing them good luck . The Battle . Infiltrating the Citadel . When the shuttle entered Lola Sayu ' s orbit , it was spotted by the Separatist blockade fleet surrounding the planet . They were immediately contacted by the Citadel and the prison ' s second in command , T - series tactical droid K2 - B4 , asked them to identify themselves and their cargo . R2 - D2 had his battle droids reply that the shuttle carried frozen supplies . Osi Sobeck , already suspecting that the Republic would attempt to rescue Piell , ordered the shuttle to be scanned for life forms . R2 - D2 and his droids nervously waited while the shuttle was scanned , but the scanners didn ' t detect any life on board and K2 - B4 gave them permission to land on the planet . The droids landed the ship in a cave near the prison tower and thawed the Jedi and clones . At this point , Obi - Wan and Anakin discovered that Ahsoka secretly came along . Anakin was angry at first , but realizing that sending her back was impossible , he reluctantly let her join . While R2 - D2 , OOM - 10 and the other reprogrammed droids stayed with the shuttle , the group began with the mission . They had to free climb a stone wall covered with electromine s in order to reach a small platform with an entrance that gave access to the prison tower . Kenobi was the first to reach the platform , but quickly ordered the group to stop moving when a droid patrol came out the entrance to check the area . Fortunately , the droids didn ' t look down , but when they went inside again , they locked the door with a ray shield . This seemed very unfortunate , but Ahsoka was able to crawl through a ventilation shaft and deactivate the shield . Meanwhile , Sobeck grew suspicious when a security droid reported that the cargo shuttle had never arrived , despite having permission to land . In the meantime , all rescue teammembers reached the entrance platform . Fives was helping clone trooper Charger up , but the latter stepped on a weak edge of stone which broke off , causing him to lose his balance and fall straight into an electro - mine , killing him and triggering the alarm . When learning of the exploded mine , Sobeck was sure there were intruders in the facility and he angrily ordered all security protocols activated and summoned his special commando droid units . The rescue team , meanwhile sneaked through the facility . They destroyed some cameras , which activated some laser turrets . Echo , Fives , Obi - Wan and Ahsoka swiftly destroyed them , but as a result an electrified wall was created that moved across the hallway and closed in on the group . Most of the team managed to take cover in one of the side halls , but Longshot was electrocuted and killed by this trap . The team located the cell where Piell was tortured . The interrogator droid was just about to gouge Piell ' s one remaining eye out when the team entered the cell and destroyed the droids . At this point , Piell revealed that his captain , Tarkin , had a part of the information as well . The team proceeded to the location where Tarkin along with two captured Naval Officers , and 3 unarmored clones were being held , but Sobeck watched them with the cameras . He had the group surrounded by his commando droids . The Jedi destroyed the first wave , but Sobeck activated a magnet in the ceiling that claimed the group ' s weapons as well as Anakin , due to his cybernetic arm . A second group of commando droids surrounded the group . The Jedi attempted to hold them off with the force but they had magnetic feet . Anakin was , however , able to , despite Sobeck using electricity on him , reclaim his lightsaber from the magnet and destroy it , releasing the group ' s weapons and allowing them to destroy the droids . This angered Sobeck and when Rex proceeded to shoot a camera , he decided to go down and take care of it himself . He was too late as the rescue team managed to free Tarkin and the imprisoned clones before he arrived . Escaping the facility . The Republic team decided to split into two groups to secure the information in case they would be recaptured . Piell , Kenobi , Cody , three clone troopers , 2 rescued Naval Officers and 1 rescued clone formed one group , while Skywalker , Tano , Tarkin , Rex , Echo , Fives and the other two rescued clones formed the second group . Kenobi ' s group went to the upper level to create a diversion , while Skywalker ' s group escaped the tower on the lower levels . Kenobi ' s group planted thermal detonator s in several hallways of the upper levels , causing explosions on several locations there and wreaking havoc in the facility . This allowed Anakin and his group to leave the tower and flee into a series of tunnels . Anakin then ordered R2 - D2 to fly the shuttle to the Citadel ' s landing platform , so Obi - Wan ' s group could be evacuated . Not long thereafter , K2 - B4 informed Sobeck that Count Dooku wished to speak to him . Dooku demanded a status report and told Sobeck that he heard about " problems " with the prisoners . Dooku asked if this matter would require his presence , but Sobeck assured him that he could handle it himself . Kenobi ' s group was meanwhile hiding in the ventilation shafts of the facility and searched for a way out . The group climbed through a to find a way out , but they were spotted by a probe droid . Piell managed to destroy the droid before it could escape to give away their position , but this caused the entire shaft to be shut with security doors . One clone trooper got stuck and was bisected by one of these doors and Obi - Wan and Even started to cut the doors open with their lightsabers . Anakin ' s group made its way through the tunnels , with Anakin protecting the flank to take out any droid that stalked them . The group came in a tunnel with a dead end and was attacked by a squad of battle droids using plasma shields to deflect shots . Ahsoka used a thermal detonator to blow them up and then blew up a wall on Anakin ' s order so they could continue . R2 and his droid squad landed the shuttle on the platform , but were awaited by K2 - B4 , who demanded to know why the shuttle was so late . 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 shuttle that the Republic had used to get on the planet had been captured . Sobeck ordered the shuttle to be guarded so they could lure the Jedi into a trap . Obi - Wan ' s group was looking at the shuttle from the shaft , but did not see R2 or his droids . Obi - Wan suspected a trap and the group went to the other side of the building to get a better view on the ship . Kenobi tried to contact Anakin , but instead heard Sobeck ' s voice , who congratulated him on his escape , but said that it was easy to predict his next move . The group was then surrounded by crab droids , droidekas , and commando droids , forcing them to surrender . Anakin ' s group meanwhile entered a big fuel pipeline to get to 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 replied that in times of war everyone was prepared to die to protect this information . Not impressed , Sobeck executed a trooper and when Piell remained silent prepared to execute another , but at that point K2 - B4 informed him that they had located Anakin ' s group and that the droids were closing in on them . Sobeck ordered the prisoners to be brought to the interrogation level for torture , while he oversaw the capture of the second group . R2 and his droids figured out that Kenobi ' s group had been captured and managed to trick the security droids that escorted them into handing over the prisoners . Ahsoka found a way out of the pipeline and looked around for the shuttle , but didn ' t spot it . The group was ambushed by droids . After leaving the pipeline , Skywalker threw a thermal detonator in the pipeline , creating a large explosion that destroyed their attackers . Realizing that something was wrong , as the shuttle hadn ' t arrived yet , Anakin led the group to the Citadel ' s landing platforms . With the droid squad that was supposed to take Anakin ' s group in gone , Sobeck and K2 - B4 tried to figure out the group ' s location . A droid then reported to Sobeck that the prisoners hadn ' t arrived at the interrogation level . K2 - B4 informed Sobeck that Count Dooku insisted to speak with him , but Sobeck ignored it as he correctly predicted that both groups would head for the airfield to steal a ship , as it would be their only way to escape the planet . Kenobi ' s group , escorted by R2 and his droids , tried to fool the droids guarding their shuttle , by telling them that they had orders to move the prisoners to another location . At this point , however , K2 - B4 informed the guards that the prisoners were trying to escape with reprogrammed battle droids . This resulted in a battle on the landing platform between the group and Sobeck ' s droids . Anakin ' s group soon joined the fight and took out the droids that manned the defense turrets . Three droids on STAPs attacked the group . Piell destroyed the first , while Skywalker hijacked the second with Piell jumping on his back to deflect shots from the third and destroy it . The group destroyed several waves of droids , but didn ' t have a chance to board the shuttle and escape , afraid that it would be destroyed . 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 defence turret to blow up the shuttle . Anakin tried 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 . To no avail , as 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 did not know however that Echo survived despite all odds and was captured and experimented on by the Separatists . On the run . 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 that would attempt to rescue them . Meanwhile , the group had to cross the rough landscape of Lola Sayu . Later , when the group contacted the council again , Yoda gave them 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 it wouldn ' t be the last droids they would face . Osi Sobeck had K2 - B4 command the blockade fleet , as he expected the Republic would launch a second mission to evacuate the prisoners , while he focused on recapturing the team . Dooku contacted him again , angry 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 . 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 outnumbered 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 them before retreating as well . Sobeck released a pack of Anooba s , creatures that could track the team down with their scent . The group heard the howling of the creatures when they came at distance and realized that the Anoobas would lead the droids right to them . Anakin and Obi - Wan volunteered to lure the creatures away while Piell led the group . Skywalker and Kenobi fought of 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 , and Piell and Ahsoka ordered the group to continue while they took care of 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 the droid responsible down . A droid on a STAP tried to shoot Kenobi , but the Jedi destroyed him with his lightsaber . An Anooba then lunged at him from behind , but Kenobi kicked the creature in a lavastream . Piell and Tano took out the crab droids , but while Piell finished the last , a remaining Anooba attacked him by surprise and mauled him , fatally wounding him . Ahsoka took care of 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 make sure that no one but the Jedi Council would get it , before passing away . The group had just destroyed the last STAPs when Ahsoka arrived with Piell ' s body . The group took a moment to honor Piell and cremated his body in the lava before moving on . Space battle and rescue . The Republic rescue fleet came out of hyperspace and approached the planet and engaged the Lola Sayu defense fleet . Saesee Tiin , Adi Gallia and Kit Fisto commanded some squadrons of ARC - 170 starfighters in their personal starfighters in order to break through the blockade for Plo 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 made it to the island that served as rendezvous point for the rescue fleet . The group now only consisted 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 on the island . Tarkin attempted to shoot him , but missed . An enraged Sobeck lifted the captain and , realizing he could never have the information from Tarkin , prepared to throw him in the lava so 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 , used a hole in the Separatist defenses and made it to the planet . They were just in time to retrieve the surviving members of the team , as a squad of crab droids overwhelmed the island . Koon ordered Admiral Coburn to recall all starfighters and , after they made it back to the command ship , the Republic fleet retreated to Coruscant . Aftermath . Once on Coruscant , the survivors met with Yoda and Mace Windu on the Jedi temple landing platform , who expressed their sadness about Piell ' s death . Yoda wanted to speak to Tarkin and Ahsoka , who had both halves of the information , but Tarkin revealed that he had orders from Supreme Chancellor Palpatine to bring his part of the information directly to him , while Ahsoka had promised Piell to bring her information to no one but the Jedi Council . Yoda then decided to personally discuss with Palpatine what the best solution to this problem would be . Before leaving , Tarkin showed his respect for Skywalker and wished there were more Jedi like him . After he left , Kenobi expressed his doubts about Tarkin and told Skywalker that the Jedi should never give up their principles even in a time of war like this .