"It is a fitting paradox that our salvation comes at the hands of our most infamous child," Rassilon says, and the Master grins. The Doctor tries to warn them about the Immortality Gate, and the Master shushes him, childlike and scary at once. "Hey, no, hey! That's mine. Hush."
He points around the room, gesturing toward the Time Lords. "Look around you. I've transplanted myself into every single human being. But who wants a mongrel little species like them? Because now I can transplant myself into every single Time Lord." Rassillon shivers.
"Oh yes, Mr. President sir. Standing there all noble and resplendent -- and decrepit -- think how much better you're going to look... As me!"
The Untempered Schism. The revolution of the infamous child. So many of us, too many of us, lose ourselves to that. We take on rebellion against the Age of Steel like it's the only alternative; we go hard just like everybody else. There's a lot to be angry about, and it's a better option but not the best option. Because the secret beneath is that it's still the Lords that did it: They drove him crazy. It's their madness he's expressing. And these are the options, for every one of us: To go mad with rage against authority, and let that be your cage. To go traveling, never letting any of it touch you. Staying innocent and young, never admitting where you come from and where you live, terrified of going hard. Or to do the third thing: To follow Wilf into the future, along the path where nothing is lost. Nothing inside must die for us to be healed.
We dream of cages, where nothing is permitted.
And to prove it -- to show that this is just another cage -- Rassilon turns back the template with a wave of his glove, healing all of Earth with a thought. He orders humanity to its knees, and the Master desperately tries to get on the other side of them again. "That's fine, that's good, because you said salvation! I still saved you, don't forget that." He shivers. Rassilon stares up, through the broken ceiling, to the sky. "The approach begins."
The Master asks the Doctor what he means, and the Doctor is exasperated: "Something is returning. Don't you ever listen? That was the prophecy: Not someone, something." As the light goes wild all around them, he explains: "They're not just bringing back the species. It's Gallifrey. Right here, right now." And Gallifrey leaps into being above Earth, red and burning.