The Daleks have treated Kaymee Arnod for the NFS plague with their miracle cure, Variant 7, but while she seems to have recovered fully, she is experiencing strange dreams in which her father Seth bids her goodbye and is then exterminated by the Daleks. As she recovers, Provost Carneill speaks with her in private, or at least he hopes it’s in private; the Daleks may very well be monitoring their conversation. He admits that they have destroyed virtually everything in the Graxis system in order to create the Healing Zones -- including the primates, which may have been evolving into a sentient species. For his part, Carneill is beginning to wonder why Kaymee is the only one of the Wardens to have caught the plague -- and he’s noticed that, while the patients cured of the NFS plague are supposedly being kept here for observation, some have started to disappear, and nobody knows where they’re going. Kaymee realises that Carneill is afraid, and he admits that, before Saxton left, he inadvertently conceded that he thinks there’s something evil about the Daleks.

Kaymee returns to her room to sleep and dreams of her father once again, and when she awakens, she finds that she’s been sleepwalking. A Dalek catches her and returns her to her room, but later, she tells Carneill that she’d seen a production line where parts of Dalek casings were awaiting assembly. Carneill admits that he’s seen that place himself, and asks Kaymee to help him find out where the Wardens are gone -- but not so he can turn them in to the Daleks. But as Kaymee’s dreams are progressing, their nature is changing; in the dreams, she finds herself trapped inside a Dalek casing, and although her father is trying to get her out, it is becoming increasingly comfortable inside. Eventually, she decides she doesn’t want to emerge, and realises that she no longer regards Seth Arnod as her father; instead, one of the Daleks in her dream claims to be her father.

Kaymee’s regular nurse stops attending her for some reason, and her food is provided by a Dalek instead. It appears unappetizing, but she finds that it tastes better than she’d expected. Carneill is starting to appear unwell, and the Daleks claim that it’s because of the high radiation levels in the Healing Zone -- but Kaymee is feeling better than ever. For some reason, however, Carneill seems concerned for her health, especially when he realises that there are no mirrors in her room and she can’t see what’s happening to her. Carneill thus tells the Daleks that Kaymee has agreed to lead him and him alone to the Graxis Wardens’ hiding place, and that he’s playing along with her in order to betray them to the Daleks. The Daleks apparently agree to let him take Kaymee out of the Healing Zone, but they are aware that he intends to take her to his human friends, who have examined her medical records and have come to certain disturbing conclusions. Kaymee’s fingers are beginning to stick together, but she sees nothing odd about that, and agrees to leave her room with Carneill -- but she stops in the corridor and refuses to go any further. She and the Daleks know exactly what Carneill is doing, and the Daleks have already located and exterminated his human allies. Carneill protests that Kaymee is still human, but that’s not really true any more, and she stands by watching as a Dalek guard arrives and exterminates Carneill.

Meanwhile, the Graxis Wardens have made their way to Scalanis 8, using false recognition codes to fool the Daleks into believing that Ranger 1 is actually the plague ship Evolution. For some reason, most of the Dalek security patrols have pulled out of the system entirely and are all heading for a much larger ship at the edge of sensor range. As the Wardens draw closer to the planet, they begin to pick up security transmissions indicating that Galactic Union agents are active and causing trouble on the planet’s surface. Saxton decides to take advantage of the security patrols’ absence, and orders her people to dip down under cloud cover to see what’s happening. They arrive above the Healing Zone just in time to see Galanar and Elaria carrying the unconscious Siy Tarkov straight towards a Dalek ambush, but the Wardens swoop down, destroy the waiting Daleks, and lower their ramp to invite the others on board. Galanar and Elaria are wary of the newcomers at first, but when airborne Daleks begin to arrive on trans-solar discs, the Demons concede that they have little choice but to board the ship. Chauley and Roozell launch Ranger 1 the moment the others are on board, and despite the Daleks’ best efforts, the Wardens outrun them and escape. The infuriated Dalek Supreme orders her subordinates to devote all efforts to finding and destroying the enemy ship.

Saxton questions Galanar and Elaria, and although Elaria is still wary and hostile, Galanar decides to trust the Wardens. He glosses over the more complicated aspects of his story but explains that Tarkov knows of a planet named Velyshaa where they can find evidence of the threat posed by the Daleks. The Daleks are also aware of the planet’s existence and are putting together a taskforce to locate it, which is why the security patrols were called away from Scalanis 8 and the Wardens’ raid succeeded. Although the Graxis Wardens were funded by the Galactic Union, they don’t particularly trust its bureaucracy; however, Saxton and Culver agree that they must put petty politics aside in the face of the Dalek threat, and as they still don’t know exactly what the Daleks hope to gain by curing the NFS plague, they decide to visit Velyshaa themselves to find the evidence that will convince the Galactic Union of the danger. But first, since they’ve been flying at top speed without time to recharge, they’ll have to find somewhere to refuel Ranger 1.

Tarkov has finally regained consciousness, and is struggling to understand what’s happened to him. Galanar and Elaria explain that, although he’s been cured of the NFS plague, the Wardens’ medical scanners have detected some extra genetic material within his DNA. However, Tarkov now knows that they’ve both lied to him -- and he’s particularly upset by Elaria’s deception, as the belief that his daughter was alive was the one thing that had been giving him hope. Yet despite this, he realises that he still trusts them, and he doesn’t understand why. Finally, he realises that they are influencing him in some way, making him trust them against his will. Furious and panic-stricken, Tarkov concludes that they’re working for the Daleks, and he begins hammering at the door, screaming to be let out.

The Wardens locate a Dalek refuelling outpost on a moon of a forgotten gas giant. There are only four Daleks on duty, presumably because the Border Worlds have bowed to their every demand and the Daleks therefore aren’t expecting trouble. Saxton is wary, but the ship is down to its last reserve stacks, and she has little choice but to authorise an attack. As the ship prepares to land, however, Tarkov breaks out of the sickbay and holes up in the engine room, hysterically accusing his companions of working for the Daleks. Galanar and Elaria are unable to calm him down, and if he damages the engines in his panic, he could end up killing them all.

Saxton takes Galanar into the engine room to talk sense into Tarkov, who hysterically accuses her of working for the Daleks. Even in his panic he seems to realise that this is going a bit far, however. Galanar admits that he’s been using a sort of trick to make Tarkov trust him, and apologises, claiming that it’s a natural reflex -- and Tarkov is forced to concede that since he no longer feels the compulsion to trust Galanar, that means that Galanar is no longer using the trick on him. Galanar thus explains to Tarkov and Saxton the truth about his and Elaria’s origins; as they recently discovered, they were removed from institutes for the criminally insane and operated upon by Daleks from another dimension, transformed into the ultimate military operatives and conditioned to imprint upon the scientists who woke them when the operation was complete. The experiment was interrupted, and 2,000 years later, Galanar and Elaria were woken from stasis -- and found themselves working for Selestru and the enemy Daleks, respectively. Galanar has since convinced Elaria that she has imprinted upon her enemy by mistake, and she’s changed sides... or so he hopes. However, he is forced to concede that, as much as he wants to, he’s not entirely sure he can trust her.

Tarkov reluctantly accepts that Galanar is telling the truth, and Galanar now explains that Tarkov is the only man who can lead them to Velyshaa and the proof they need to convince the Union of the Dalek threat. Tarkov is still unwilling to trust him, and especially not Elaria, but Galanar reminds him of the determination he voiced in his distress call from the Crusader; perhaps after all he’s suffered since then, he’s lost sight of that determination, and if this is the case, Galanar promises that he won’t force Tarkov to help them. After a moment, Tarkov asks Elaria if he really had a daughter, and Elaria is forced to admit that the real Amur died in the same shuttle crash that took her mother’s life. Tarkov does not believe that Elaria is really as sorry as she claims, but he does agree to emerge from the engine room and direct the Wardens to Velyshaa.

Ranger 1 lands near the Dalek fuel depot, behind the cover of a small ridge. Three assault groups set off to take the base; Culver, Roozell and Chauley keep watch from the ship as Telligan leads one of the three squads. The Daleks are apparently taken completely by surprise when the Wardens attack, and the Wardens overpower and destroy them. Tarkov, watching from the ship, is surprised to learn that twelve Wardens have taken out four Daleks with only six human casualties. During the fighting, however, there was a brief power surge in the depot that they are unable to explain; they are unaware that one of the Daleks slipped away from the battle and carried out certain instructions given by the Dalek Supreme.