The Mystery of Chopper Base " The Mystery of Chopper Base " is the twentieth episode of the second season of the animated television series " Star Wars Rebels " . It is the thirty - fifth episode of the series overall . The episode , directed by Bosco Ng and written by Steven Melching , premiered on March 23 , 2016 on Disney XD . Official description . " The rebels finally locate a potential site for a secret base , but find their new home is not as isolated as originally believed . . . " Plot summary . Building a new base . Following the discovery of Atollon , the Phoenix Squadron has established a base on the planet . The starship " Ghost " departed the rebel fleet ' s " Quasar Fire " - class cruiser - carrier to deliver a shipment of power generators to CT - 7567 ( " Rex " ) , who was supervising the establishment of the base . After contacting Rex , Hera Syndulla and Sabine Wren entered the cargo hold where Ezra Bridger and his master Kanan Jarrus were sparring with lightsaber s . The lightsaber training session ended in a draw with Ezra pointing his blade at Kanan ' s neck and Kanan pointing his blade at Ezra ' s chest . When Kanan lectured Ezra that there were no such things as ties in combat , Ezra responded that they won by killing Inquisitors . Kanan then replied that they won by surviving . Ezra expressed annoyance when Sabine said that he was getting better since he took it as sign that he was not as good as before . After Hera reassured Ezra , Kanan reminded his apprentice not to turn his back on his enemy . The two Jedi then continued sparring . After the " Ghost " landed at the rebel base , Kanan attempted to make conversation with Hera but she was still uneasy about Kanan and Ezra ' s plans to go away . Shortly later , Garazeb Orrelios and Chopper disembark from the " Ghost " . Upon arriving , Hera told the former Imperial inventory droid AP - 5 that the crate containing the power generators had arrived . AP - 5 grumbled that the shipment was due hours ago and asked Chopper whether the rebels were always late . The astromech droid squeaked an affirmative . At the command center , Rex briefed the Spectres and told them that his scouts had found a water source underground . Sabine and the other scouts had been planting sensor markers around the base ' s perimeter to ward off potential intruders . Zeb was annoyed about a small critter known as a dokma . Rex surmised that Atollon was hot , dry and unpleasant but conceded that the planet harbored nothing that was trying to kill them . Meanwhile , the rebel pilot Lieutenant Dicer was planting a sensor beacon in the northern perimeter when she was ambushed and captured by a krykna , a large spider - like creature that was native to Atollon . Back at the base , Hera ' s elation at establishing a new rebel base was dampened by her awareness that Kanan and Ezra would be leaving with Ahsoka Tano to travel to Malachor . Kanan tried to reassure his companion that the Jedi knew what they were doing . He stressed that the Jedi had to continue with their mission so that the rebellion could succeed . Meanwhile , Sabine and Rex received a report that Lieutenant Dicer had not returned and that they were receiving no communication from her . Hera dispatched Rex and Sabine to take the " Phantom " to the northern perimeter to find Dicer . Meanwhile , on the " Ghost " , Chopper bumped into Ezra . When Ezra asked the astromech droid whether he had seen Zeb , Chopper pointed him in the direction of a nearby cliff overlooking the desert and several giant coral plants . Upon arriving there , Ezra found Zeb relaxing and listening to some music while watching the sun set . When Ezra confided in Zeb that he was about to leave and expressed his fears that they would never meet again , Zeb reassured his younger friend and joked that he and his friends would have overthrown the Empire by the time that Kanan and Ezra had returned . He suggested that they could then share war stories . Facing the Krykna . At the northern perimeter , Sabine and Rex found Dicer ' s sensor marker but could see no sign of the scout . Rex spots her helmet and finds a pair of dokma under it . Rex speculated that Dicer was taken after she had planted the sensor . The two rebels were then attacked by several large krykna . Sabine managed to hold them off with her two blaster pistol s and call for reinforcements but Rex was captured by the krykna . Shortly later , the " Ghost " arrived and managed to drive the krykna away . After the ship landed , Sabine told Hera that the creatures had taken Rex and Dicer . Hera then told Chopper to locate Rex ' s position with his antenna . While Zeb wanted to guard the ship , Hera told him to come along and instructed Chopper to guard the ship . Chopper flew the " Phantom " back into the " Ghost " and stayed aboard the ship . Meanwhile , the rebels ventured into the underground tunnels with Ezra and Kanan using their lightsabers to provide lighting . Sabine then told the other rebels that the krykna had thick armor but their eyes were vulnerable . As they moved deeper into the tunnels , Hera told the rebels to split up . She send Ezra and Kanan to explore one section while she and the other rebels explored the other . Hera then explained that they had to get used to not having the Jedi rebels around . Shortly later , Kanan and Ezra ran into a krykna . Ezra tried to use the Force to connect with the creature but was unable to establish a connection . Kanan was forced to kill the creature with his lightsaber . When Ezra protested , he chided his apprentice for lacking common sense . Meanwhile , Hera and the other rebels stumbled upon a lair littered with several spider eggs . They managed to free Rex from a sleeping krykna ' s mandibles but were unable to find Dicer . Shortly later , they were pursued by several krykna . Sabine managed to kill one of the krykna with a detonator but was unable to stop their advance . As more krykna approached , the rebels shot at them with their blaster s . The rebels were quickly rejoined by Ezra and Kanan . After a struggle , they managed to fight their way back to the " Ghost " where Chopper lowered the ramp so that they could board the ship . As they were boarding the " Ghost " , Kanan remarked that the base wasn ' t a good location but Hera refused to give up . Hera attempted to fly the ship but the " Ghost " was held down by a large web spun by the krykna . Ezra , Kanan , and Zeb used the ship ' s laser cannon s to blast the krykna but were unable to break the ship free of the web . Under Hera ' s orders , Sabine diverted all auxiliary power to the hull . This had the effect of electrocuting one of the krykna but the spidery creatures were not deterred for long . Ezra then realized that the rebels were not going anywhere unless they broke free of the krykna ' s web . When Zeb expressed a reluctance to go , Ezra angrily replied that he did not want to be the last Jedi in the galaxy to be chomped up at the hands of creatures because they were too afraid to go outside . At that point , Sabine realized that the krykna did not like the sensor markers and suggested using them to hold them at bay while they escaped . Putting Sabine ' s plan into action , the rebels staged a counter - attack and broke out through the ramp . Meanwhile , Rex fought off a krykna which had managed to enter the rear exit of the " Ghost " . Back at the front , Ezra and Kanan used their Force powers to hurl Sabine towards the sensor marker . However , they threw her too far and she landed at the top of a pit . Back at the " Ghost " , Rex and Chopper managed to work together to expel the krykna . After Rex had kicked it out , Chopper sealed the ship ' s rear exit . At the front line , Sabine managed to crawl out of the pit and grab the sensor marker before a krykna could catch her from behind . The Mandalorian then used the marker to force her way back to the ship . After Sabine arrived back on the " Ghost " , Ezra and Kanan used their lightsabers to cut through the krykna ' s webs around the " Ghost " . This allowed Hera to lift off the ship and ferry the rebels safely back to base . When Rex suggested reporting to Commander Jun Sato that the base was unsafe , Hera responded that the rebels had already poured so much effort into the base and reiterated that they would not give up . Kanan backed her up and came up with the idea of using the sensor markers to form a fence around the base ' s northern perimeter . Taking separate paths . The following day , Sabine and Kanan watched as several rebel troops erected a fence using several sensor markers . Sabine also told Kanan that Hera wanted to speak to him . She explained that Hera was supportive of the mission but was worried about never seeing Kanan or Ezra again . Kanan then approached Hera and tried to assure her that he and Ezra would be alright . However , Hera sensed that he was lying and confided that she preferred that they face any challenges together . Kanan then reassured Hera that they would see each other again before hugging her . Meanwhile , Ezra made a second attempt to connect with a krynka at the northern perimeter . However , his efforts were futile and Ezra fumed in frustration . Shortly later , Ahsoka arrived and spoke with Ezra . When Ezra told her about his predicament with the krykna , she explained that the Force became more mysterious as one learned more about it . Ezra then followed Ahsoka back to the camp but stopped briefly to gaze at the sensor perimeter and the flora ahead . Above , an owl - like creature known as a convor hooted before the screen panned out .