Purity ( audio story ) Purity was the second story in the " I , Davros " series released by Big Finish Productions . Publisher ' s summary . " We are Kaleds . We are more than a match for weak , tattered , crippled relics of the war . " Now approaching his thirtieth year , Davros is trying to get out of the Kaled military and into the Scientific Corps , determined to use his mind to create new ways to let the Kaled race survive the never - ending war with the Thal s . But first , he must undertake a mission into Thal territory . A mission that will introduce him to technology and hardware he could only dream of . And it just might teach him a few life lessons too . But however dangerous the Thal City might be , that is nothing compared to the scarred relics that inhabit the Wastelands . . . Wastelands that Davros and his team have to cross twice . . . Plot . Still a captive among his creations , the Daleks , Davros continues his recounting of his past . Young Davros , now nearing thirty years of age , has joined the Military Elite as a Tech - Officer . With his friend and fellow officer Reston , he works on refining and testing new weapons developed by the Scientific Corps — a posting that Davros greatly desires for himself . He grows frustrated at their repeated failures with the new weapons , and believes he can do better for his people — and then he is summoned to the office of the highest leader of the Kaleds , the Supremo . His meeting with the Supremo is tense , with Davros displaying his arrogance , until the Supremo makes an offer . Davros , he explains , will be sent on a mission to infiltrate the city of the Thals ; and using his prodigious scientific skills , he will disable and destroy a new weapon under development . If he agrees , and succeeds , he will be promoted — perhaps even to the Scientific Corps . Although Davros tries to agree at once , the Supremo sends him home to think about it , swearing him to secrecy . At home , he encounters his sister Yarvell , whose sympathies have increasingly come to lie with the peace activist factions . Their mother , Calcula , is out buying art , a lifestyle which both Davros and Yarvell agree she cannot afford any longer . It sparks an argument ; their father left the family ’ s money in trust in Davros ’ s name , on condition that he marry ; as he refuses to find a wife , it cannot be released . The argument turns to the war ; Davros is scornful of their enemies , the Thals , but Yarvell tells him that recently - discovered ruins indicate they were once a single society with the Kaleds . As Davros repudiates Yarvell ’ s claims , Calcula arrives at home with a new work of art : a portrait of Davros . Her doting on him disgusts Yarvell , who only reluctantly stays for dinner . Later , the three relax in the family ’ s pool ; but soon the discussion turns into another argument about the war — Calcula supports it , as always , while Yarvell argues against it . Davros sides with Calcula . Yarvell again brings up the money , but Calcula defends Davros ’ s decision . As the argument peaks , Davros accidentally reveals his upcoming mission . As Yarvell storms out in anger , Calcula determines to use her own contacts to learn more of the mission . However , she then returns to the topic of wealth ; Davros decries her words , and tells her the only way she will obtain the trust fund is when he dies . Davros recommends that Reston join him on the mission ; the request is approved , to Reston ’ s surprise . In the Covert Operations section , they are introduced to their team leader , Major Brint , who gives them the details . They are to infiltrate a recently - discovered and heavily - guarded weapons facility , steal what they can , and destroy the rest . Accompanying them will be six commandos ; Davros will be second - in - command after Brint . A diversionary attack will take place at the same time , giving them some form of cover . The group departs . Later , at midnight , the team reaches a minefield , and watch as the diversionary attack begins . Davros suspects they may be beyond the mines already , though they lost at least one commando en route . The mission is running behind and falling apart ; suddenly it is beset by a Thal patrol , which manages to kill another commando . Escaping , Davros determines that Brint is not leading well , and takes command . By the following nightfall , they reach the mountains . Davros begins to suspect that the unusually numerous Thal patrols have somehow been waiting for them — but only the Supremo should know they are here . Another patrol approaches ; Davros seizes control from Brint again , and lures the Thals into a trap . They overwhelm the Thals and take their uniforms . Brint catches Davros making notes about Brint ’ s conduct , for later use in requesting an inquiry , but he is unable to do anything about it for now . Meanwhile , Reston notes that they can see the stars and the two moons , which is impossible inside the cities due to the war ’ s pollution ; he wants to build a home here after the war , but Davros scoffs at that dream . Viewing the Thal base , they learn that the Thals are constructing numerous long launch ramps . Brint intends to blow up the base , but Davros stops him ; he and Reston will infiltrate it instead . If it is as he believes , he will be able to obtain the much - needed intelligence and still destroy the base . Brint allows it , but promises to destroy the base and them with it if the mission is compromised . Davros and Reston have little trouble getting inside , and they find the base nearly deserted ; its production line is automated . In fact , the entire base is one large , robotic factory , run by advanced computers — an accomplishment currently beyond the Kaleds , and admirable . Davros confirms that the factory is making sustained - flight rockets — hence the ramps . Moreover , the rockets have advanced , adaptable guidance systems allowing for great maneuverability ; the intelligent systems mean that no pilot is needed . This system could win the war in a single stroke . Davros and Reston take notes and images . In a nearby office , Reston learns that half the Thal economy has gone into this project — a crippling financial blow , should it be lost . They are caught by a Thal patrol , who promise that they will be tried and shot as spies — but , more strangely , their commander calls Davros by name . The Thals are eliminated by Brint , who has come to find them . Reluctantly , they set the charges to destroy the base , and evacuate , meeting up with their remaining team members . Shortly thereafter , the base explodes . Knowing the remaining Thal soldiers will be after them , Davros recommends that they flee through the wastelands to the north rather than back over the mountains . Brint objects , believing rumours of cannibalistic , mutated survivors in that area , but Davros insists . In the fog of the wasteland , the group is separated ; before they can regroup , another commando , Vander , is lost . They encounter a terrible , plantlike creature , which attacks them , forcing them to kill it . However , Davros is horrified — and fascinated — to see that the plant was , until recently , Vander ! Davros collects some samples , including the spines which the plants use to infect their victims ; however , this results in a final argument between Davros and the now - terrified Brint . Davros accuses Brint of betraying them and leading them to their deaths ; Brint denies it , but turns over command to Davros , and walks into the fog . Davros , Reston , and the final two commandos make their way through the wastes , until — with the thinning of the fog — they find they are surrounded by the carnivorous plant creatures . Some nearby ruins provide the only sanctuary ; as they run to them , Davros remembers Yarvell ’ s words about ruins to the north . This must be the ruin of that decadent society , but it will do for shelter if they get there before dark ; after all , the plants have no eyes , meaning that in the dark , the plants will have the advantage . Inside the ruined city , the atmosphere feels wrong . Davros splits the team in two to search the place , sending Reston in charge of the second pair . The group is forced back together by a pack of armed scavengers ; they open fire , but the attackers have the advantage of numbers . At last the scavengers are killed , but so are the two remaining commandos , and Davros ’ s gun is depleted . One survivor remains ; Davros finds that it is his old tutor , Magrantine . Magrantine is dying despite his hate for Davros , but first , Davros questions him about the plants , as he remembers something from a book that seems familiar . Magrantine calls them “ Varga ” , from an old Dal word for “ Devourer ” ; they consumer flesh , and inject their seeds into their victims so as to spawn . The plants have evolved mobility due to the toxins in the air and water ; now they hunt their victims . Davros is intrigued , and wants to develop them into weapons . Meanwhile Magrantine explains what happened to him ; after his ordeal in the radiation chamber , Calcula had him dumped outside the city . He survived his mutations , and was picked up by the deserters and other refugees in the wastes — everyone the Kaleds and Thals have put out . He has survived on his desire for revenge against Davros . He cannot attack Davros now , as he lacks the strength ; but he curses Davros , wishing a similar fate on him . He dies moments later . Reston has fallen asleep , but awakens ; Davros assures him he hasn ’ t missed anything . They watch the Varga plants feeding on the slain scavengers . One plant pleads with them for help ; they realise it is Brint , now a victim . Davros denies his wish , and they depart while the rest of the plants are distracted . Nearing the Kaled lines , Reston demands to rest , as he is exhausted . Davros spurs him on ; but in his exhaustion and recklessness , he climbs the nearby ridge — while still wearing his stolen Thal uniform . The Kaled automated defences cut him down . He is alive , but cannot walk . Davros offers to carry him , but Reston knows it will slow them down and allow snipers to catch up ; he demands to die with honour , as per military protocol . Davros remembers his father ’ s denied wish to do the same , and says he cannot understand wanting to die ; he becomes angry , and tells Reston that people like him are holding the Kaleds back . He then shoots and kills Reston with Reston ’ s own pistol . Later , Davros awakens in a hospital , with Calcula at hand . She explains that he was picked up , exhausted and dehydrated ; but she is proud of him . He tells her that someone must have known about the mission and betrayed him ; she realises that he suspects her . She forcefully objects , insisting that she would never rob Davros of the greatness he was born for ; to Davros , that only leaves Yarvell . Calcula agrees , and insists she will take care of it . Yarvell swims alone at home , listening to a radio broadcast of a message she herself recorded on behalf of the new Peace Confederation . Calcula enters , and tells her that Davros is dead . Yarvell is shocked , but quickly moves on to practical details of the funeral to be planned ; Calcula explains that he was killed on the mission behind the Thal lines , as the Thals knew he was coming — knew his name , in fact , as well as his face . At last , Yarvell admits to having warned the Thals by way of the Peace Confederation ; she admits that she had grown concerned about what Davros might do if he was placed in the Scientific Corps . However , she didn ’ t want Davros dead , just stopped . Calcula reveals that Davros is not dead , and declares that Yarvell is a danger to Davros , just like her father Nasgard and aunt Tashek — whose deaths , she admits , she arranged . She attacks Yarvell , and drowns her in the pool . Calcula tells Davros that she found Yarvell drowning and tried to revive her , but was unsuccessful . After all , there was Davros to think about . Davros suggests spinning Yarvell ’ s death as a murder by a Thal infiltrator within the Peace Confederation . He promises to protect his mother ; Calcula , meanwhile , intends to get Nasgard ’ s will overturned , releasing the money to support them both . . . after Yarvell ’ s cremation . Later , Davros begins to experiment on Yarvell ’ s body ; he intends to keep this a secret , as his mother expects a cremation . In what he considers poetic justice , he combines her DNA with that of a Thal and a Varga plant , intending to make weapons to win the war . . . by the power of science .