Back in the Galactic Union, Bulis Meitok’s people have gone through Giorgi Selestru’s data systems and have found positive proof that he has been conducting illegal covert ops against the orders of the Union Council. However, they’ve also found positive proof that everything he told Meitok about Galanar and Tarkov was true. If he is right that the Daleks pose a terrible threat to the Union and Meitok does nothing about it, then the Union is doomed -- but if he’s wrong and Meitok decides to support him, the consequences could be even worse. Selestru’s future, and the future of the Union, hinge on what Meitok decides to believe.

The human medics on Scalanis 8 are beginning to feel unwell, and when Mevis investigates, she learns that the Healing Zone has been flooded with an exotic type of radiation that the ordinary scanners were unable to detect. The human medical personnel in the Zones are slowly dying... and the patients cured of the NFS plague are changing, as if their very genetic code is being rewritten. Mevis informs Japrice, whose first instinct is to warn the Daleks that something’s going dreadfully wrong -- but Mevis has already realised that the Daleks are the ones responsible for this. Japrice tries to demand answers, but the Daleks exterminate both her and Mevis.

Elaria vanishes from the sensors on Ranger 1, and the Graxis Wardens eventually find her hiding in the engine room. Saxton puts her in Galanar’s custody, much to Elaria’s bitter amusement, as she knows that this isn’t what Galanar had hoped for when they were reunited. As far as she’s concerned, he is just fooling himself by pretending to be human. He insists that she can still win back her humanity if she fights for it, but when he asks her what she was doing in the engine room, she admits that she feels comfortable there because it reminds her of the stasis capsules on the Pkowik system. All she wants to do is return to the womb and stop fighting. Galanar reluctantly begins to realise that he and Elaria really are nothing alike, and, disturbed, he decides to speak with Tarkov instead. Tarkov is still somewhat hostile, but he concedes that he can’t spend the entire six-month journey to Velyshaa holed up in his room. At Galanar’s request, Tarkov tells him his story and the story of the Dalek War. Much later, while being interrogated by the Dalek Supreme, Galanar tries to explain that, despite the grim nature of the story and their desperate mission, they were still able to find moments of humour and acknowledge their shared humanity. Odd as it seems, over the next six months, he and Tarkov became friends -- and that’s something that Galanar believes the Dalek Supreme will never understand.

Telling the story of the Dalek War gets Tarkov pondering the nature of their mission to Velyshaa. The Union is currently stable and at peace, but that’s about to come to an end -- and if this war is anything like the last one, then good people will have to become as ruthless and brutal as their enemies in order to survive. Ranger 1 arrives at Velyshaa six months later, but as the Wardens set course for the planet, they detect an sensor echo from its surface and realise that another ship is lurking just beyond detector range -- and that their pursuers no longer care if they are spotted. Saxton, Galanar and Tarkov set off to confront Elaria to see if she knows how the Daleks managed to follow them; Tarkov is convinced that Elaria is responsible, but Galanar knows that this is because he’s still hurt by what she did to him. But while Tarkov now regards Galanar as a genuine friend, he is just as aware that Galanar wants Elaria to be innocent so that he’ll no longer be alone.

When confronted, Elaria claims that she hasn’t signalled the Daleks, but admits that, even though she consciously knows them to be wrong, she is still driven by her imprinting to serve them. She also reveals that she knows what the Daleks are planning -- and that the human race hasn’t a hope of defeating them. Since the Daleks were all but wiped out by the Great Catastrophe, they no longer have the numbers necessary to conquer this galaxy; thus, they unleashed the NFS plague on humanity so they could swoop in and provide a “cure.” Every patient who has received Variant 7 now has extra genetic coded embedded in their DNA, which, when activated by a specific sort of radiation, will mutate them into Daleks. Just before he was captured on Scalanis 8, Galanar saw a production line set up to manufacture Dalek casings; soon, the victims of the NFS plague will be transformed into the largest Dalek army ever assembled. And now that the Daleks have traced the Wardens to Velyshaa, they’ll soon wipe out the only evidence that could have convinced the Galactic Union to take action before it’s too late.

Elaria still claims that she didn’t help lead the Daleks here, but she’s aware that the others don’t believe her. She is thus restrained aboard the ship as it lands on Velyshaa, and as Tarkov leads the others out onto the surface, Elaria bitterly asks Culver to kill her and get it over with; she doesn’t trust herself, and is convinced that they’re all going to die soon anyway. Outside, Tarkov leads his friends to Kalendorf’s burial chamber, where he is reunited with Saloran Hardew and her associate, Jake. 20 years on an abandoned planet have not been kind to Saloran and her people, and as Tarkov spent most of those 20 years in cryogenic suspension, she’s now considerably older than he is. Tarkov introduces his friends, explains the situation and admits that, due to circumstances beyond his control, he lost the data that he was supposed to be taking to the Galactic Union. She agrees to provide him with another copy -- but time is running out, as the Dalek battle cruiser is on its way.

The Dalek battleship swoops down and opens fire on Ranger 1 before the Wardens are prepared, and Culver has no choice but to lift off and try to outrun them. Most of the Daleks are committed to the assault on the burial chamber, but they are able to spare a squadron to pursue the Wardens’ ship. The Wardens duck down into a trench to avoid the Dalek patrols, but they are unable to land within the trench, they’ll be destroyed the moment they emerge, and hovering will burn their fuel reserves and render them incapable of leaving Velyshaa. Out of options, Culver calls Elaria to the bridge and asks her to use her insight into the Daleks to help them.

Saxton and her Wardens set up a defensive perimeter around the burial chamber as the Dalek battle cruiser approaches the ruined city. Hopefully, the Daleks intend to analyse the data left by Kalendorf before destroying it; if so, they won’t simply open fire from their ship. Saloran finishes downloading a copy of the data and destroys the original, leaving Tarkov with the only copy in existence -- but until Culver returns, he’s got no way to get it off the planet to safety. As the Wardens consolidate their positions outside, Saloran settles down for a nap in the burial chamber, telling Tarkov that she’s been expecting something like this ever since Tarkov showed her proof that the Daleks had returned. She’s had plenty of time to accept her fate, and knows that none of them can control the future; all they can do is their best, and hope that the next chapter of history is a good one.

The Daleks are in position, and the Wardens are horrified when hundreds of Daleks emerge from the ship and attack. The Wardens try blocking the streets with explosives, but they’re hopelessly outnumbered -- and they receive an unpleasant and demoralising shock when Ranger 1 suddenly swoops in out of nowhere, barrels straight towards the Dalek ship, and is shot down in flames. The Wardens are now stuck on Velyshaa with no way off, but as the Daleks close in on them, Culver and Elaria arrive with reinforcements and help to drive back the attackers. Realising that Ranger 1 was doomed regardless of what they did, and that the Wardens would never get off this planet alive, Elaria advised Culver to abandon ship and sacrifice it by remote control. Instead of trying to escape with the data store, she and Galanar must use their Demon tricks to help Tarkov break into the Dalek ship and access their hyperbeam transmitter; it’s powerful enough to reach the Dalek Supreme in Seriphia, and is more than capable of contacting the Galactic Union. The Wardens must keep the Dalek army occupied until Tarkov has succeeded, a task that will undoubtedly mean all of their deaths.

Saxton sends three of the Wardens with Galanar, Elaria and Tarkov while the others, including Culver and Telligan, remain by her side, prepared to fight the Daleks to the last man. That is Saloran Hardew, who is woken from her nap by Daleks bursting into the burial chamber and demanding to know where the data store is. She informs them that she’s given it away, and faces her death with dignity. Meanwhile, Galanar feels guilty about leaving Saxton and the others to die, but he has little choice. The raiding party boards the Dalek ship and reaches the communications chamber before the Daleks detect their presence on board. The Wardens stand guard outside while Elaria realigns the hyperbeam controls to transmit to the Galactic Union, and Tarkov, though he still doesn’t trust her, has little choice but to hand over the vital data. Elaria activates the transmitter and collapses in hysterical laughter as the Daleks break in, having killed the three Wardens -- but to Elaria’s shock, instead of killing her for her treachery, the Daleks take them all alive for interrogation.

Tarkov, the first to be interrogated by the Dalek Supreme, laughs triumphantly when she tells him that they were unable to halt the transmission. The Dalek Supreme then asks him why humans resist the Daleks when the Daleks are clearly the superior life form, and although Tarkov scoffs, he slowly comes to realise that this was a genuine question and that the Dalek Supreme wants a genuine answer. He refuses to accept that the Daleks are indeed superior, but admits that, in order to defeat them, humans will have to go to war -- which means that human society will become just a paranoid, aggressive and uniform as the Daleks. The Dalek Supreme points out that the Daleks survived their last defeat, and reveals that she was once human herself and has brought new human ways of thinking to the Dalek race. Under her guidance, the Daleks will triumph -- and, like it or not, Tarkov will be part of that future. Horrified, Tarkov realises what she’s telling him; he has been exposed to the radiation that will trigger his own mutation. Tarkov screams his late wife’s name in despair as he realises that he is already starting to become a Dalek himself.

Galanar and Elaria have been locked up together, and Galanar is trying to remain optimistic, hoping that Giorgi Selestru will be able to convince the Council Elders of the truth once he receives their transmission. But his optimism is getting on Elaria’s nerves, and she thus suggests that it’s possible Selestru may never receive the message -- because it’s possible that she never sent it. Maybe the Daleks allowed the Wardens to capture the fuel depot because that fuel had been altered to leave a trail behind it... or maybe Elaria really was signalling to them all along. Or is she just provoking him now? As the stunned Galanar demands to know the truth, a Dalek enters to take him away for interrogation -- and when he demands to know where his friend is, the Dalek informs him that Tarkov is becoming a Dalek. Elaria laughs as the last of Galanar’s so-called optimism withers away, and the enraged Galanar snaps and kills her, just as she wanted all along.