At the bomb site, the Doctor does his trick again, summoning the nanogenes. They sparkle and flutter around his hands. Rose asks what he's up to, and he answers, "Software patch. Gonna email the upgrade." He looks at the camera through a golden haze: "You want moves, Rose? I'll give you moves." He hurls the cloud toward the masks, still bumping around on the train tracks, and they all fall to the ground, surrounded in the haze. The Doctor's joy: "Everybody lives, Rose. Just this once. Everybody lives!"
The masks stand up, and they all have faces. They're people again. The Doctor skips and jumps and bounds and pirouettes and arabesques and triple lutzes over to Dr. Constantine: "Dr. Constantine, who never left his patients. Back on your feet, constant doctor! World doesn't wanna get by without you just yet, and I don't blame it one bit." He gestures to the people all around: "These are your patients. All better, now!" Constantine's totally confused and funny: "...So it seems. They also seem to be standing around in a disused railway station. Is there any particular reason for that?" The Doctor waves it off and hints at more: "Whatever was wrong with them in the past, you're probably gonna find that they're cured. Just tell them what a great doctor you are, don't make a big thing of it. Okay?" I love how time-travel paradoxes are as easy as: "Hush hush, okay? Nanogenes and the fall of the Wehrmacht, but that's just between us." The Doctor runs off, and an old lady hobbles toward the doctor of Albion: "Dr. Constantine. My leg's grown back! When I come to the hospital, I had one leg." He cocks his head at her: "Well...there is a war on. Is it possible you miscounted?"
The Doctor calls out to the recovered denizens of London, standing on the transport: "Right, you lot! Lots to do! Beat the Germans, save the world! Don't forget the Welfare State!" Constantine smiles up at him, and leads his people back to Albion. The Doctor tells Rose that he's setting the transport to self-destruct -- "History says there was an explosion here. Who am I to argue with history?" Rose grins: "Usually the first in line." They smile at each other. It wasn't a war, not really. It was an invasion, of sorts. But the spirit of the Blitz is the spirit of love -- strong, no-bullshit love. The kind of love that would push you to call out a shamed mother on her shit, the kind of love that would take her over the edge of fear and shame and into strength. The kind of love that Nancy, holding her deadly child and waiting for the change to come, or the next bomb to drop, wouldn't expect anyone to understand.