On the battlefields of Skaro, Captain Brogan oversees an execution squad fulfilling their duty “for the greater glory of the Kaled nation”. The event is witnessed by Colonel Nasgard, who later questions why the Captain seemed unhappy with the task. Brogan explains that they were simply a handful of soldiers who panicked momentarily. Nasgard dismisses them as traitors and says deserting one's post is the worst thing a soldier can do. He believes the strictest discipline must be maintained at all times and it falls to people like them to make this world a safer place for their children. Nasgard's children, Davros and Yarvell, mean everything to him and he'd willingly die or kill to protect them. Brogan notices one of the condemned men is still alive, despite being riddled with bullets, so he calls for the medic, but Nasgard shoots him again and kills him outright. He argues that they've already wasted ammunition on these cowards and he sees little point in wasting medical supplies as well. The bodies are to be buried in unmarked graves to avoid the Thals discovering there was dissent in the ranks. Nasgard begins coughing, providing Brogan with further evidence that he's not a well man.

At a busy social function, Lady Calcula, personal assistant to Councillor Quested, is engaged in a heated debate about the war. She believes the war is a useful way of keeping people out of trouble as it creates full employment and provides the young with skills and opportunities to progress... should they live long enough to take advantage of them. Councillor Quested arrives and tells her that the Council has been summoned to an emergency meeting and he needs her to deal with any enquiries on his behalf while he's away. She asks what the meeting is about, but he won't discuss it while others are within earshot, so he invites her back to his apartment afterwards. As he leaves, Calcula is joined by the lecturer Magrantine, who flatters her by suggesting she'd be better than Quested at coping with the pressure of high office. He asks for a moment of her time to finalise the syllabus for Davros's education, but she has no interest in the matter and says her only requirement is that it satisfies his thirst for knowledge and prepares him adequately for the future. She's paying Magrantine an obscene amount of money to give her son the best start in life, but he says his only interest is in making sure the gifted Davros receives the best possible education and that he would willingly offer his services for free. Calcula refuses to consider such an offer as she has no wish to be in debt to the man, and she suggests he discuss the syllabus with Davros instead as only Davros knows what subjects will interest him.

Tashek, Nasgard's older sister, calls her niece Yarvell in from the cold as she's worried Calcula will blame her should anything happen to her children while she's away from home. However, Yarvell doesn't think her mother would even notice if something happened to her, as Calcula only has eyes for Davros. He's two years younger than Yarvell, yet he's allowed to do what he wants while she has to obey all the rules. At the age of 18, Yarvell is training to be a soldier, but she's getting frustrated at how long it's taking to become an officer, so Tashek reminds her that everyone has to serve their time in the Military Youth. Tashek tells Yarvell to go and fetch Davros, who's either going to be in his room reading the old Dal book he admires so much or sitting by Drammakin Lake.

Lady Calcula looks down at the city from Councillor Quested's apartment window and is pleased that it's remained relatively intact despite being so close to the Thal border. She doesn't want to stay too long in case her sister-in-law accuses her of putting career before family; she can't afford to upset the person who makes it possible for her to keep the lakeside villa where her husband's family have lived for generations. Quested reveals that the war has reached an absolute stalemate and the Council is at a loss what to do, but Calcula thinks the war has been going nowhere for centuries. The Thals seem to be able to anticipate and block their every move, to such an accurate degree that there must be a spy in their midst. Someone in a privileged position and with a wealth of high security knowledge is obviously passing information on -- possibly even someone from within the Council itself. Quested suggests that even if there isn't a spy, it might be useful to invent one, just in case...

Down by the lake, Yarvell is shocked to find her brother Davros swimming in the water as they've been warned that all sorts of things could be living in there. Davros shows her what appears to be a rock that he found at the bottom of the lake and when she holds it, she can feel it move in her hand. He explains that it isn't a rock at all, it's a protective shell and there's a creature living inside. She tells him it's disgusting and he seems surprised that she has no interest in other life forms. He believes her there's more to Skaro than just Kaleds and Thals, no matter what outward shape life takes and how many legs it has. He thinks they evolved from creatures not dissimilar to this and maybe in a million years they'll evolve back into it.

Colonel Nasgard summons Captain Brogan to his field tent and tells him he's received a communiqué from central command. The substance of the message is that Nasgard has been relieved of his duties with immediate effect and Brogan has been promoted to senior officer. He sarcastically congratulates Major Brogan and the younger officer says it's all come as a big surprise, but Nasgard knows it was Brogan's own reports to headquarters that led to this in the first place. Brogan claims ignorance, but the Colonel has been sent full copies of all the correspondence, which he shows the Major. The letters provide details of Nasgard's health problems and his erratic behaviour, and he challenges Brogan to provide evidence of his accusations. The younger officer is furious as his letters were meant to be confidential. However, he could no longer ignore what was becoming obvious to everyone -- Nasgard hasn't been well for some time -- so he wasn't acting out of personal interest but because he has a responsibility for the welfare of everyone, including Nasgard himself. The Colonel accepts that Brogan acted out of good faith and admits he would have done the same if their positions were reversed. Brogan offers to arrange an escort home so he can rejoin his family, but Nasgard hands over his pistol and orders the Major to shoot him where he stands. This is military protocol and he demands the right to an honourable death on the battlefield. Brogan refuses as the Colonel could live for weeks or months, possibly even years, so he won't deny him the time he could spend with his wife and children.

Davros is angry with his mother for arranging extra lessons for him, especially from Magrantine, as he finds the man irritating. Calcula says Magrantine speaks very highly of him, and adds that she's gone to great lengths to arrange it all so he's being a little bit ungrateful. The teacher doesn't give extracurricular lessons to everyone, although Tashek suspects he's probably being paid quite well. Davros insists that he doesn't want any extra help and that he just wants to be left alone, but Calcula thinks a boy of his age should be interacting more with people and developing his social skills. Yarvell tries to stir things by claiming she wouldn't mind extra lessons, but Davros says they'd be wasted on her and Calcula agrees that Yarvell is hardly destined for a future of academic excellence. Tashek rebukes her sister-in-law, but Calcula points out that she doesn't have any children of her own, so she should allow Calcula to bring Yarvell and Davros up as she thinks best. Tashek reminds her they won't be children for much longer and it's a pity she's not at home more to watch them grow into adults. She adds that she's held her tongue too often in the past when it would've been better to speak out -- Calcula may be a powerful woman in the world of politics but not in this house, where she's expected to be a wife and mother first. Calcula accuses her of hiding away from the real world and reminds her they're at war. Yarvell becomes frustrated and embarrassed by the family argument, but Davros orders everyone to be quiet as he can hear a Military Elite cruiser arriving outside. Realising it's their father, the children rush outside...

Magrantine greets Councillor Quested, who arrives unexpectedly at his laboratory. The politician knows the scientist has made a special study of nuclear fission and therefore understands the subject better than most, especially the potentials and the dangers. He asks what would be the likely consequences of a nuclear strike on the city and Magrantine replies it would be total devastation. Buildings would be razed to the ground and thousands of people would be killed by the blast and the heat. Those who survived would face the unknown perils of radioactive fallout -- sickness, disease, starvation or worse. In all the experiments he's conducted to test the effect on living organisms, the result has been the same -- death. Quested asks him to step up his experiments and asks for a demonstration of the radiation chamber, and is shocked when Magrantine reveals they're both standing inside it right now! He assures the politician they're quite safe as it can only be operated from the other side of the door. Quested does his best to appear nonchalant and then makes an excuse to leave.

Major Brogan helps Colonel Nasgard into his home, and when Tashek sees how frail and ill he looks, she immediately recommends that he sit down. Calcula comments on Brogan's promotion and realises her husband has been forced to retire after his health finally let him down. Davros coldly asks him if he'll be dead soon and when Yarvell objects, Nasgard simply comments that such honesty is refreshing. He assures Davros he still has plenty of fight left in him, but Brogan believes he's pretending his health is better than it actually is. For Nasgard, the war is over and Brogan hopes he too will see an end to it in his lifetime. Calcula criticises his blind faith and points out that unless they gain a tactical advantage over the Thals, nothing is ever going to change and soldiers will continue to perish. Brogan believes the war will be won by politicians, but Calcula disagrees -- she thinks the war can only be won by scientists and by technological developments. Tashek thinks they should save this discussion for a more suitable time and Brogan prepares to leave the family to talk, but Yarvell urges him to stay as the journey back will too hazardous at this late hour. When Nasgard is alone with Davros he asks why he's being so quiet, and his son says he didn't expect to ever see him again and thought he would be killed in battle. He tells his father that he wants to be a scientist to help bring the war to an end, but Nasgard objects strongly, insisting that Davros train as a soldier and follow in the family tradition -- while also telling Davros to strive for what he wants to do.

Major Brogan collects his belongings from the cruiser outside and Yarvell thanks him for bringing her father back home. She believes her father is basically a good man, but Brogan says war does terrible things to good people and drives them to extreme behaviour, bringing out the worst in them. She points out that it can also bring the best out of people and he thinks she's very wise for such a young person. He admires the family home and the fact that you can see the two moons without looking through a chemical haze. Here everything seems so clean. He's sure the war will end one day and believes some people will do anything to bring that day forward...

Nasgard angrily accuses his wife of poisoning Davros's mind against him, but she says the only poison is the kind he was breathing in all those years on the battlefield. She believes anyone with any self-respect would have given in by now and she wonders why he didn't ask Major Brogan to shoot him through the head. When Nasgard tells her Brogan refused to do it, she questions the kind of men being recruited into the military these days and for the first time they agree that there's too much liberal parenting and not enough discipline. That's why he believes Davros should be forced to serve his time in the Academy and then pursue a military career, but Calcula refuses to sacrifice her son for such a futile objective as ending the war. Without the war, she argues, the Kaled race are nothing; they depend on the continuation of the war for their existence, to give them meaning, purpose and a reason to live. But Nasgard believes they should fight to win the war, not to keep things as they are. In the next room, Tashek finds Davros eavesdropping on his parents' argument about what's best for his future. He notes that they never argue like this about Yarvell, but Tashek says her future is more straightforward and she knows what's expected of her. She also observes that Yarvell is her father's daughter, but Davros is not his father's son, then she tells him to go to sleep.

Calcula receives a communication from Quested telling her that the members of the House of Congress have been recalled to the city for a crisis meeting; he thinks it likely they'll be seeking to negotiate peace with the Thals. He recommends she bring her family with her to keep them safe, but she argues that her husband is too ill. Quested is surprised to learn that Major Brogan is staying with them and demands that Brogan report to him first thing in the morning.

The next morning, Nasgard compliments his daughter on her military uniform and Brogan agrees that it's quite distinguished. Her father is very proud of her and regrets that Davros doesn't share her interest in soldiering, but Tashek advises him not to push the boy. Nasgard hands Yarvell his medals; he was planning to give them to Davros, but now he thinks she would appreciate them more. Meanwhile, Calcula finds Davros by Drammakin Lake and tells him it's time to leave. He's cradling the body of a dead bird which fell from the sky, and he's curious because nothing dies of old age on Skaro. He thinks it was contaminated by some kind of poison in the air, which means the poisonous chemicals must be coming closer. It may not be long before the lake itself is affected.

When Quested meets Brogan he asks about Nasgard's condition and learns that he's weakening and has been acting irrationally. He's clearly unfit for command and the Councillor agrees that Brogan did his duty in sending the reports. It's a difficult time for the Council and the war has reached a critical stage, so senior members of the Military Elite must be completely dependable. Quested is worried about Nasgard's wife, but Brogan thinks she's a tough woman and personally he's more concerned about the children.

Lady Calcula takes her children to meet Magrantine, who welcomes Davros back to the school. Calcula says Davros is very excited about his extracurricular lessons, but she doubts the teacher has ever met her daughter before as she's not exactly what you'd call “bookish”. Yarvell is in military uniform and salutes Magrantine, but as he's a civilian Davros thinks she's being stupid. Magrantine acknowledges Calcula's pride in her children, but she accuses him of trying to patronise her. She's due to attend an urgent meeting at the House of Congress, so she leaves the teacher with instructions to provide her with a daily report showing how Davros is getting on so she can make sure her money is being well spent. She leaves with Yarvell, then Magrantine offers to give Davros a guided tour of the education complex after which they can discuss the syllabus. Davros is hostile to the teacher and objects strongly to being addressed as “my boy”.

Back at their home, Nasgard tells his sister he can hear a strange noise, but she can't hear anything unusual and assumes that because he's been away for so long, his ears are sensitive to every sound the house makes. He's upset by her insinuation that he's imagining it and he accuses everyone of conspiring to make him believe he's ill when he's not. She tells him he's been ill for many years, since before Davros was even born, but he claims that can't be true as he sired a perfectly healthy child. She breaks the news to him that he isn't Davros's real father. Nasgard is shocked and doesn't believe her, but she tells him the poisons in his body had already done their work before Davros was conceived and he'd long been incapable of producing any more children. She saw his medical records when she was a nurse and the evidence proved conclusively that he was sterile. Calcula knows that Tashek has discovered the truth, which is why she's always hated her so much, but in return Tashek hates Calcula for not having the courage to tell Nasgard the truth and for putting Davros ahead of Yarvell at every opportunity. Nasgard thinks he can hear the noise again, and this time his sister can hear it too. He suggests they check the communicator in case Calcula left it switched on, which gives Tashek another excuse to berate Calcula for wasting valuable energy. While they're searching, Nasgard asks if she knows who Davros's real father is, but before she can answer, they find a strange-looking device that was hidden in the communicator room. Nasgard realises straight away what it is -- but before he can do anything, the device suddenly explodes...

The tour of the education complex ends in a room which Magrantine describes as the centre of his world -- his laboratory, where the impossible is made possible. The classroom where Davros will be spending much of his time is next door, so Magrantine can keep an eye on him. Davros refuses to be patronised and although he has no desire to attend these lessons, he assures Magrantine he won't have to watch over him every second of the day. It was Calcula's wish that the syllabus be tailored to Davros's particular interests and Davros is interested in the radiation chamber. The teacher says he uses it to analyse the effect of different levels of radioactivity on a variety of materials and Davros is fascinated to learn that Magrantine uses living animals as test subjects. Although he doesn't actually disapprove, he questions the teacher's right to subject any sentient being to such dangerous experimentation, knowing that it will die. Magrantine points out that a scientist must keep his emotions and his work separate from each other and that most of the greatest discoveries throughout history were made at the cost of someone else's pain and suffering. Nothing matters more than the truth and sacrifices must sometimes be made in the search for scientific enlightenment. He asks Davros if he's ready to make sacrifices...?

Yarvell is devastated by the news of her father's death. Major Brogan tries to comfort her by pointing out that Nasgard and Tashek were at the centre of the blast and wouldn't have suffered. Yarvell can't understand who would want to kill him, but Brogan says there are millions of Thals who'd want him dead, not to mention the odd Kaled. Yarvell tries to cling to the hope that they weren't in the house when it blew up, but the Major confirms that both their ID chips registered a termination at the time of the explosion. She swears vengeance on the people who committed this crime and he notes sadly that this means the cycle of violence will continue as each side seeks to avenge what the other has done. He tells her there are better ways to strike back, and the best of these is not to strike back at all. Yarvell warns Brogan that he's starting to sound like a pacifist, but he says he'd prefer to be called a peace activist or just a soldier with a conscience.

At the school, Calcula tells Davros his father and Tashek have been horribly murdered. She adds that there's nothing to go back for now so she suggests they make their home here in the city. Davros coldly asks for permission to go back to his studies as he's keen to be present when Magrantine opens the radiation chamber. Calcula agrees as work is by far the best antidote to grief. Moments later, Calcula is joined by Councillor Quested who's just heard the news. He suggests she must be devastated, and she claims that she's in pieces -- not as many as her late husband, of course, but pieces nonetheless. He's curious as to the cause of the explosion, as he knows there haven't been any Thal missiles falling near the lake, and he suspects it may have been a bomb planted to assassinate her! She admits that she's always felt too vulnerable there and believes she and Davros should have been better protected. And Yarvell, of course. Quested asks about Davros, and Calcula says he's very upset and misses his father almost as much as she does.

Magrantine returns to the classroom and finds Davros reading up on some of his old experiments. He's interested in finding out more about the mutated plants mentioned in the reports but Magrantine explains that they were deemed too dangerous by the Council and he was ordered to destroy them. Both he and Davros agree the councillors were fools as there was a lot of potential in the plants, but Davros has been able to break the code in which Magrantine wrote the records and can prove the teacher disobeyed his orders. Magrantine offers Davros his condolences and the boy realises he's trying to change the subject so he suggests continuing with their experiment. He asks whether anything has survived inside the radiation chamber and Magrantine invites him in to see for himself. As they enter the laboratory, Davros is immediately struck by the smell of scorched flesh and Magrantine explains that prolonged exposure to radiation causes alterations to the genetic make-up, including both internal and external mutation. Alas, the subjects rarely survive and certainly not for long. Davros realises this makes it impossible to know what the ultimate form of such mutation takes and for the first time Magrantine understands that his student regards the experiment as a form of evolution. The teacher offers to go inside the chamber alone as the effects of the radiation are still a little unpredictable, but Davros insists on seeing the results of the test for himself.

Calcula returns home and is surprised to find Yarvell there after being excused service for the day because of the news about her father. Calcula is outraged that the platoon leader could be so “soft in the head” and she orders her daughter to put her uniform back on and go back outside to face the world. Yarvell accuses her mother of not being upset, but she explains that the display of any emotion in her profession is interpreted as a sign of weakness. She won't allow the people who caused this atrocity to have the satisfaction of knowing how deeply affected she is and she thinks Yarvell should do the same. Yarvell accuses the Thals of being responsible, but Calcula says she doesn't think this is likely and that the truth probably lies a little closer to home. She directly implicates Major Brogan, but Yarvell insists he'd never do such a thing -- and when Calcula suggests he might be a spy, her daughter blurts out that he's a peace activist and would never hurt anyone. The revelation that there's a peace activist inside the Military Elite horrifies Calcula and she suspects he's been manipulating Yarvell. When her daughter points out that Brogan could easily have killed Nasgard on the battlefield without anyone suspecting, Calcula concludes that his plan was actually to wipe out the entire family, including Yarvell.

In the House of Congress, an air-raid siren signals the evacuation of the building. Major Brogan reports to Councillor Quested and tells him one of their own missiles has been launched into a densely populated area of Thal territory. The Council gave no such order so it must have been an automatic response to the fact that a similar missile is heading in their direction on an almost identical trajectory. Quested is relieved to hear it isn't a nuclear missile, especially as Magrantine's latest experiments in that field make for uncomfortable reading. Brogan urges Quested to join the other evacuees into the shelters, but he prefers to stay where he is -- but when Brogan tells him the Thal missile is heading for somewhere east of the city centre in the vicinity of the education complex, the Councillor realises that's where Davros is.

The Thal missile reaches its target and the damage to the education complex is considerable. Magrantine calls out for Davros's help as he's trapped under some fallen masonry. The youngster urges him to stay calm and struggles to pull his teacher clear before the rest of the wall collapses. Eventually he succeeds and Magrantine is relieved to discover he has no broken bones. There isn't much left of the classroom any more and Davros says all they can do now is alert the rescue parties to their presence, but the teacher refuses to wait around for the next missile to arrive and he insists they both leave the area immediately.

Brogan reports back to Quested. Casualties were minimal and although a few buildings were damaged, it's nothing that can't be repaired. He's worried they may not be so lucky the next time and the Councillor agrees they must prepare themselves for the further attacks that will inevitably come. He believes this was nothing more than a rehearsal and the next attack will be on a much larger scale. He reveals that the Council has discussed the possibility of constructing a protective dome that could cover the entire city and if a nuclear strike does go ahead they can only hope there's something left that's worth protecting. Calcula arrives to demand news of her son and they tell her Davros was seen leaving the complex with Magrantine shortly after the explosion and they both appeared to be unharmed. Calcula turns on Major Brogan and directly accuses him of not evacuating the education complex in time, but he points out that his orders were to evacuate the House of Congress first. She reminds him that since he deposed her husband he's a senior officer in the Military Elite and he should have acted like one, making the orders instead of merely following them! Brogan makes his excuses and returns to supervise the rescue operation. Once they're alone, Quested says Calcula was being unfair but she says he was wise not to place complete trust in Major Brogan. She reveals that he's a peace activist, which must surely conflict with his military responsibilities. Quested is concerned that Brogan didn't reveal his personal beliefs to him personally, and Calcula wonders if there's anything else the Major hasn't told him...

Davros and Magrantine have walked miles and eventually stop for a rest on top of a hill overlooking the city. Davros is concerned that the rescue parties will be looking for them in the wrong place, but his teacher says they've come too far to turn back now and he should think of this as an educational excursion. The light is starting to fade and Davros wants to go back, but Magrantine urges him to look to the other side of the hill where there are thousands of miles of desert with a line of mountains in the distance. Magrantine suddenly reveals that the desert was where his son was murdered -- by Davros's father! The teacher pulls out a gun and the boy realises he wasn't brought here to enjoy the view. Magrantine explains that his son was blindfolded and executed after being accused by Nasgard of running away. Davros refuses to be blamed for his father's actions, but Magrantine is angry that someone else killed Nasgard before he had the chance to do it himself. He thinks the bomb was too quick and that Nasgard didn't suffer enough. Magrantine wanted him to lose every member of his family, one by one -- starting with his innocent little boy. This is the real reason he offered to give Davros unpaid tutorials if necessary, just in order to get close to him. It amuses Magrantine to think that Calcula will never find out what happened to Davros, unless someone stumbles upon his shallow grave by chance. Davros is disappointed as he thought Magrantine was genuinely interested in his intellectual development, but the teacher assures him he is and he actually regrets the loss of such a promising young life. His own son always wanted to be a scientist too, but he lacked Davros's intelligence and died as a humble and now disgraced Corporal. Magrantine's personal ambitions died with his son and all he has now is the desire for revenge, but Davros points out that if he gives in to his emotions he will cease to be a true scientist. Davros suggests there are things he can learn from Magrantine that he would never have been able to teach his own son. Slowly, Magrantine comes to realise he can't go ahead with it and he powers down his weapon. Davros asks to take the gun, just in case he changes his mind...

Quested tells Calcula that her son and Magrantine did the right thing by removing themselves from the area until the danger had passed. Calcula is relieved and felt sure the teacher would keep Davros away from any real harm as his best student is so important to him. Quested believes this latest attack has underlined the need for greater security for Calcula and her children as well as the other members of the Council, but she assures him she can look after herself. He points out that her income will be limited now her husband is dead, but she reminds him that until the Thal spy in their midst is exposed and dealt with, every single one of them is in a vulnerable position.

Magrantine thinks it's a miracle that his laboratory is still intact when most of the building was destroyed and that they weren't killed when the missile struck, and Davros thinks he must be leading a charmed life as he's come close to death three times today. Magrantine says he's truly sorry about what happened on the hill, but he was blinded by grief. He'd appreciate it if it was never spoken of again, and Davros assures him the incident is already forgotten and he'll say nothing of it to his mother. Magrantine and his radiation experiments are too important to him and there's still work to be done. Davros will need his teacher to explain the next batch of test results, but Magrantine hasn't even selected the subjects yet. Davros points out that several people were killed during the missile attack and a number of others were injured and are close to death. He suggests their research would be better served by a study of how radioactivity affects the Kaled metabolism and they could use the near-dead as test subjects. The information they learn will provide greater long-term benefits for their people in the event of a nuclear war. Magrantine agrees readily and says the hospital can supply them with their next 'volunteers'.

Quested argues that although Major Brogan may be a peace activist, that doesn't make him a spy, so while his political views are inconvenient, he's not necessarily an enemy of the Kaled people. Calcula insists that he's a traitor -- a soldier who's unwilling to fight, who questions the orders of his senior officers and who manoeuvred himself into a position of authority to get close to the Council. Worse, he then attempted to cover his tracks by killing the man he usurped. Quested reminds her that she has no proof, but she knows Nasgard invoked the military protocol of honourable death on the battlefield and Brogan refused. She believes he did this as an excuse to visit their home in order to plant the bomb. She wonders whether it was just coincidence that the Thal missile came down on the education complex where Davros was studying, but Quested thinks this is no more than wild supposition and such arguments could be used to construct a case against anyone, even Calcula herself.

Davros observes as Magrantine performs an autopsy on one of the bodies they've been experimenting with in the radiation chamber. He recognises some of the internal organs, but notes there's also a lot of neoplasm and some unfamiliar tendrils. Magrantine believes the ribcage was starting to melt and change as a result of the intense radiation. Davros wonders whether it's an established fact that their bodies mutate so rapidly, but there's been very little practical exploration of this thesis and unfortunately the body they're examining would have survived only a few minutes inside the chamber. They've been starting to make good progress, but this was the last of the victims from the hospital who were unlikely to survive anyway, so Davros suggests they start looking elsewhere for more 'volunteers' to help them continue their research. Magrantine wonders whether Davros finds anatomical surgery fascinating, but the word he chooses is “exciting”. At least this way the lame and the sick are helping the Kaled people and nothing goes to waste.

Councillor Quested accompanies Calcula to watch her daughter's first participation in an execution squad. Yarvell was hand-picked by the Council from the Military Academy, a sure sign that she's growing up. She's been told that a traitor has been discovered, but she's surprised to learn that the man she's about to execute was also involved in her father's death and was planning to destroy her entire family. The squad fall into line as the prisoner is escorted out and when the cover is removed from his head, she's horrified to learn that it's Major Brogan. He protests his innocence and Yarvell demands an explanation from her mother, convinced that Brogan stands for peace and isn't a traitor. Calcula insists that Brogan had the motive, method and opportunity to murder Nasgard, and she orders her daughter back into line under threat of being shot herself. Yarvell realises that neither Calcula nor Quested hold a military rank, so they shouldn't even be here, and she claims the court martial is a travesty. Calcula turns on her daughter and reminds her that she's a soldier and a student of the Military Youth, so she has a responsibility to perform her duty. Regretfully, Yarvell agrees to do as she's told. The execution squad prime their weapons as Brogan calls out that his only crime was to want peace, but Calcula twists his words so they appear to be a confession. The squad opens fire and Brogan's body falls to the ground. Quested thanks the squad on behalf of the Kaled nation, and for Calcula this is a proud day indeed.

Later, Davros returns home and finds Yarvell alone. She tells her brother that Calcula is attending a meeting at Quested's apartment. Davros tells her he wanted to speak to their mother about the execution, but he can talk to Yarvell instead as Major Brogan was her friend. She still believes the wrong man was executed and she recalls him saying that war can do terrible things to good people. Now she also thinks war can allow bad people to get away with terrible things. She no longer knows whether she wants to be a soldier, not if it means having to kill innocent people. She tells Davros that Brogan only wanted to help find a peaceful solution to the war and her brother wonders if that means the Major would have agreed to help him too. She thinks he would, so Davros asks her to find out whether he can have Brogan's body for medical research as it would be such a waste if his body was just burned or thrown away. Yarvell is horrified at the suggestion and pushes Davros away, calling him a sick, cold-hearted monster. She screams at him and tells him she no longer regards him as her brother.

Quested proposes a toast to the end of the war, but Calcula reminds him it isn't over yet and he's being a little optimistic. However, he thinks that if her suspicions about Brogan were correct, it'll soon be possible to break the deadlock and have victory in their sights. Calcula is worried that if any of his fellow Councillors see them celebrating, they'd think she got used to the idea of being a widow very quickly. He urges her to find another husband, but she admits she wasn't particularly happy in her marriage to Nasgard, so it might be better to remain aloof and alone from now on. Quested reminds her she has two children to provide for and has dwindling finances. He knows her burden will grow heavier with time, so he offers to share what he has with her. For a moment Calcula is speechless, then Quested asks her to marry him as they should have done many years ago. He also wonders if Davros should finally be introduced to his real father, but Calcula will only do that when she considers the time is appropriate. Quested thinks Davros is old enough to understand, but Calcula is worried he'll resent her for keeping the truth from him for so long. Tashek came very close to telling Davros on a number of occasions and Calcula regrets not silencing her years ago...

Davros tells Magrantine that he was unable to secure Major Brogan's body for them as his sister became loud and abusive at the idea. His teacher isn't too concerned, as he really wants a living body for their next experiment because their last 'volunteer' died too quickly to be of any real use. The effect of the genetic mutation was far less dramatic than it might have been so he suggests they try again with someone else. Davros wonders whether his sister could be 'persuaded' to volunteer herself. Magrantine asks him to collect some samples from outside the radiation chamber, but once he's stepped outside, Davros slams the door shut, trapping the teacher inside. He tells Magrantine that he wants to find out what happens to living healthy tissue when the radiation is set to maximum power. His teacher demands to be released and threatens to tell Davros's mother, but Davros plans to visit her right now at Quested's apartment and tell them Magrantine committed suicide over the death of his son. He leaves the laboratory, ignoring the desperate banging on the chamber door...

The argument between Quested and Calcula is becoming heated as the Councillor insists Davros has the right to know who his real father is. Calcula believes this would hurt her son as the lineage of Nasgard is held in high regard by Kaled society and she doesn't want that reputation tainted by scandal or gossip. However, Quested argues that although he's respected her wish to say nothing about their relationship for the last 16 years, it was always understood that should the situation change they'd be able to form a more permanent and visible partnership. Calcula laughs and says she never felt they'd have anything other than a working relationship, which Quested finds amazing as they had a child together. He's worried Davros will believe his mother became pregnant simply to further her own ambitions. He tries to persuade her they have nothing to be ashamed of and nothing to hide, but she tells him she's gone to a great deal of trouble to cover her tracks. It was useful that Major Brogan shouldered the blame for the deaths of her husband and his increasingly indiscreet sister, but perhaps he was an innocent scapegoat for the real spy -- and Quested has been making a number of "diplomatic" visits to the Thals in recent years. Calcula reminds Quested of a quote he made recently -- even if there isn't a spy, it might be useful to invent one, just in case... It suddenly dawns on him that Major Brogan was executed purely on Calcula's evidence and that she condemned an innocent man. He grabs her and demands to know how many other people have died because of her. At that moment, Davros arrives and orders him to leave his mother alone. Quested assures Davros he wouldn't hurt either of them, but Davros pulls out Magrantine's gun. The Councillor reveals that he is Davros's father, but the boy refuses to believe it and shoots Quested dead before he can say anything more.