With the Dalek ship crashing, Susan, Alex and Lucie scramble to get to the Doctor. They manage to get him back to England, where the TARDIS heals him.
The Monk and Tamsin are gathering priceless works of art. Tamsin, entirely Locked Out of the Loop
, thinks that the Monk is preserving human culture so that humanity can rebuild itself after the plague. The Daleks, she thinks, are medical volunteers.
So, when the Monk is forced at Lucie's gunpoint to confess, Tamsin is absolutely horrified. After the Dalek Time Controller was destroyed by the Doctor
, he was propelled back in time. The Daleks sent out a distress call, hoping to lure in a particularly stupid Time Lord. The Monk answered. He patched up the Time Controller, who went on to tell the Daleks what would happen in their future. And in order to prevent that, the Daleks repeated their invasion of Earth
, and persuaded the Monk to sow the plague across the planet. But this time, their plan to drag the Earth across the universe was more elaborate: the Earth will now function as a plague planet, spreading the sickness throughout galaxies. The Monk helped the rebels, then the Daleks, and then, as the battle progressed, mostly just himself. Tamsin is sick with guilt from the revelation. It doesn't help much, as the Daleks see no need to keep her alive. She's exterminated moments later. So is Alex, in a fantastic Heroic Sacrifice
The Doctor decides that all the rules of time can go to hell, and plans to drag a nuclear bomb through time to prevent all this. Because if he ever gets a chance now to kill all Daleks forever, he will
, no matter if it's genocide, no matter if it breaks time, no matter what it would mean for his own rules. Lucie takes the decision out of his hands by dragging the bomb into the Dalek mineshaft instead, and she dies in the process.
The Monk, mourning Tamsin's demise, reveals that he was the one who caused the Doctor to show up two years too late. And that he had feelings for Tamsin. The Doctor doesn't even want to hear it, and he sobs and roars at the Monk to get out. He and Susan try to decide how to go on living after all this. The Doctor wants to snatch Lucie away from the explosion at the last moment; Susan reminds him that he can't, and shouldn't, change history. With a hasty goodbye to Susan, the Doctor heads back into the TARDIS, where he plays Lucie's recording over and over, speaking along with it and filling in his own lines. Deeply traumatised and just a little off the deep end, he promises her that he shall come back for her, one day, he shall come back.
- Break the Cutie: The Doctor really is completely broken at the end of the episode. He says that "people die and the Doctor moves on, but not this time."
- Call Back: The Doctor's state of mind at the end is parallel to Six roaring with grief at the end of "Arrangements For War". Six had Evelyn to stop him from going back in time to save the girl; Eight has Susan to remind him of what's right and what's wrong.
- Continuity Nod: Many, but most notably, we see the exact moment the Eighth Doctor becomes willing to regenerate into the War Doctor who would eventually end the Last Great Time War. He promises the Daleks that he'll commit genocide on them one day, he wishes to become as cold and ruthless as he was back when he almost murdered a man to save his own hide, he very seriously considers breaking the laws of time, and he can't bring himself to forgive a fellow Time Lord any longer.
- Cruel Mercy: The Dalek Time Controller plans to leave the Doctor on Earth as it is infected by the viruses, as he will survive longer then the humans and see the world die. The end is this to the Doctor and Susan, Susan has lost her son, the Doctor has lost his Great-Grandson and his friend. It's even this for the Monk, who has lost his friend and realises how much trouble he has caused.
- Death by Disfigurement: Lucie.
- Downer Ending: One of the biggest in Doctor Who's history.
- Dying Moment of Awesome: "And just in case you wanted to know who it was who blew you to pieces —- the name is Lucie Miller. You got that? Lucie BLEEDIN' MILLER!"
- Easily Forgiven: Subverted. Despite the Monk saving him and Susan the Doctor is still furious at him and tells him to leave.
- Even Evil Has Loved Ones: The Monk, though not entirely evil, clearly feels this way towards Tamsin.
- Fandom Nod: Lucie calls the Monk "The Meddling Monk", the first time he's ever been called that out loud in all of Doctor Who.
- Grand Finale: For the New Eighth Doctor Adventures. The Eighth Doctor promptly takes a nosedive into Darker and Edgier territory from here as the Dark Eyes series begins.
- Heroic Sacrifice
- Set Right What Once Went Wrong: The Doctor wants to do this by going back to the Amethyst Station with the bomb and making sure to destroy the Dalek Time Controller. He is stopped.
- Meaningful Echo:
- A very Dark Reprise of the First Doctor's "I shall come back" line.
- The Doctor's final scene very strongly evokes Charley's goodbye in "The Girl Who Never Was". Only much, much more dramatic.
- My God, What Have I Done?: The Monk after Tamsin is exterminated.
- Opinion Flipflop: The Monk will say anything to please the Daleks. Because he's terrified, selfish, and above all, a complete blithering idiot.
- Plague Master: The Dalek Time Controller's plan is the original Plague plan Up to Eleven. He plans to drive Earth through space, infecting other worlds with the Amethyst viruses.
- Pet the Dog: The Monk saving the Doctor and Susan.
- Screw the Rules, I Make Them!: Says a variant of that to Susan, when he's considering going back and snatching Lucie just before the bomb goes off. Susan basically tells him he'd be Jumping Off the Slippery Slope if he did, so ultimately he decides against it.
- Shoot the Dog: Happens thrice. Tamsin, Alex and Lucie.
- Time Travel for Fun and Profit: The Monk hopes to steal the art treasures of the worlds the Daleks conquer and become "the richest man in all creation".