For rigorous teachers seized my youth,
And purged its faith, and trimm'd its fire,
Show'd me the high white star of Truth,
There bade me gaze, and there aspire.
-- The Grande Chartreuse (1855)
On once-beautiful Gallifrey there is a bottle city, fire and downed spaceships everywhere. Within, they walk across a bridge in a falling-down place, entering through a huge and lovely broken gate. Two stand guard outside the room: President Rassilon stands at the head; the mad Visionary sits at the foot. Six in total. Six for Hell.
The Visionary scribbles in the last moments of the Time War. The Doctor has disappeared, but they know his intention: "He still possesses the Moment," a Time Lady warns, "And he'll use it, to destroy Daleks and Time Lords alike." The Visionary confirms it: "Ending burning falling all of it falling the black and pitch and screaming fire, so burning..." All the prophecies agree: This is the end of the Time War. Gallifrey falls, and the Time Lords die, today. At the Doctor's hand.
"Perhaps it's time," says the Time Lady. "This is only the furthest edge of the Time War. But at its heart, millions die every second. Lost in bloodlust and insanity." The mad Visionary, the old hag, letters and symbols and time written over her body in an endless black flood, stops to listen. "With Time itself resurrecting them, to find new ways of dying, over and over again, a travesty of life." She is proud; there are tears in her throat. "Isn't it better to end it, at last?" Rassilon stands, thanks her for her opinion, and vaporizes her where she sits. His spittle and his madness. "I will not die! Do you hear me? A billion years of Time Lord history riding on our backs? I will not let this perish. I will not!"
The petty fears of empire. Another man speaks, as the Visionary scrabbles in time. "There is one part of the prophecy, my Lord. Forgive me... I'm sorry, it's rather difficult to decipher, but..." He points at the gorgeous whorls of her writing, the intertwined and timeless madness. The out-clause speaks of two survivors, two children of Gallifrey, beyond the Final Day. They are unnamed, beyond signaling their final confrontation: "The Enmity of Ages." The Time Lords assembled know what that means. The Doctor, who doctors, and the Master, who masters. And one constant word: The salvation of Gallifrey, the single point around which the Doctor revolves, the place his hearts are hidden: Earth.
The Master's problem isn't madness, not even the madness of war: it's his belief that there's a fundamental and insurmountable difference between him and anything else. The Master believes that he's alone. He is mistaken.