Planet of Kadril Planet of Kadril is a comic strip that was written by Russ Helm and illustrated by Alfredo Alcala . It was republished on StarWars . com ' s webstrips section of . Plot . Kunda stone s — used in the construction of lightsabers , various medicinal devices , and comlinks — are grown and harvested on the planet Kadril . Soon after the destruction of the Death Star , Luke Skywalker , the Princess Leia Organa , captain Han Solo , and Chewbacca traveled here to secure a trade deal between the Kadrillians and the Rebel Alliance . Unknown to the Rebels , however , the Sith Lord Darth Vader had also come to Kadril , to secure his own crystals . Vader had developed a chemical compound , pacifog , which enhances the weakest traits of most victims . However , it is deadly to humans , causing their flesh to become a frothy ooze . Vader wanted Kundas stones to place in the masks of stormtroopers , as the stones made perfect filters against the pacifog gas . Using the gas on Lon Prador , Kadril ' s Lord Councilor , Vader used Prador to order the Kadrillians to gather up all the planet ' s Kundas . But , the greatest concentration of the stones were to be found among the hills where a group of anti - technology Kadrillians , the Nocivs , lived . Visiting the Nocivs at that time was Deerna , the betrothed of young Rodno , who was the assistant to Kardril ' s leading scientist , Dal Quirz . Quirz was administrator of the Zero - G lab , where perfect Kunda stones were grown . Fearing for Deerna , and knowing that the Nocivs wouldn ' t obey Prador ' s edict ( thus putting them at odds with the Imperial forces ) , Rodno convinced Solo and Skywalker to accompany him to the Nocivs enclave . Once there , after meeting with Mdel , the elder of the village , the Rebels were attacked by stormtroopers . Among the casualties of this assault was Mdel . Meanwhile , back at the Zero - G lab , Princess Leia and Chewbacca decide to use a small repair pod to disable an orbiting relay satellite , thus disrupting the Empire ' s broadcasts . As Chewie was too big to fit in the pod , Leia took it up . As the funeral for Mdel commenced , troops stormed the Zero - G lab , capturing Leia and Chewie . Vader ordered the troopers not to harm Leia , but to do as they would with the Wookiee . Using the gas on Chewbacca , however , only resulted in his sneezing … and getting angry . During the ensuing battle , between Chewie and the troopers , Princess Leia activated a device created by young Rodno , a Vibro - Crystal , which shattered the Kundas in the stormtroopers ' filters . Leia quickly contacted Luke , telling him of the invention , then she and Chewie commandeered the shuttle the troopers had used to reach the lab . Leia and Chewie are followed to the Nociv village by Imperial forces , and barely arrive in time to deliver the Vibro - Crystal before they are attacked . Using the Vibro - Crystal , the Rebels and their newfound allies manage to defeat the Imperials , and Leia then takes the Vibro - Crystal to Vader ' s headquarters , destroying all Kunda stones in the vicinity . Vader then orders a full evacuation of his troops from Kadril , realizing that with this new weapon , pacification of the entire planet would be impossible .