When I watched End of Time the first time, I skipped around to the action sequences and watched the end. Recently, when the first ep of season 5 came out, I rewatched EoT and found myself thinking about all the symbolism. This is what came out of it. Third person, but Master-centric. No slash intended.
The sound of the drums. Can you hear them? 1, 2, 3, 4. 1, 2, 3, 4. The heartbeat of a Time Lord, the four quarter notes in your head.
All his life the Master heard the noise, the drums, the beating. Was he mad? Was he crazy? Was he insane? Yes, probably, maybe. Most likely.
And all his life the Doctor, the "sanctimonious" little Doctor, would always be there to stop him, to eliminate him, to humiliate him. Oh no, but not this time. Never. This moment right there, with the diamond star and the return of Gallifrey, this was his moment.
Of course, things never turn out the way he plans them. Just take Utopia as an example. The Lord President came through, and his council, and the Time Lords and the whole of Gallifrey. Straight from the locked Time War itself. But it wasn't glory; it wasn't conquest. It. Was. A.
And all the time, since the beginning, the Doctor was trying to tell him that. Trying to hint in every battle, in every passing remark that something would come eventually. Something not someone. In the end, everything fell into the hands of that Doctor again. With the gun in his hands, he had to choose between his people, or the Master –his enemy but also his friend.
Choose Doctor, the Master thought through the drums. Choose. You're not righteous. You're no better than me.
The Master could have sworn for a moment the Doctor would kill him.
"Get out of the way."
"Back into hell Rassilon!"
The Doctor pulled through as he always did. He didn't have the guts to hold that gun and kill someone. The link. The link had to be broken. But the Master, Koschei, he knew what that meant. Directly defying the Lord President was a one-way ticket to death and yet the Doctor did not flinch at the glove. It was almost as if he expected it.
But there was an old human saying from Earth: an eye for an eye, a tooth for a tooth. A debt for a debt. The Doctor tried to make him see and open his eyes, but the Master in all his pride and arrogance heard and refused to listen. This sanctimonious Time Lord needed a break.
"Get out of the way!"
The Master unleashed his full fury on Rassilon, on his own people. In the end he really was a koschei. He had the guts to betray his own people after all this time. But in the end, he refused to let the Doctor died. He was finally starting to see, starting to realize why the humans had called to him in their time of need during the Year that Never Was. Sometimes, he was a saint. This Doctor came in and left a trail of death, but saves the day anyway. And he doesn't ask to be thanked. This Doctor tries to make people see the good and uncover the bad. Sometimes they listen and sometimes they don't.
The Time Lords needed to live on. What good was the mighty race of those who conquered time and space if there was no one left? The Master was dying as it was. There was no chance for him, but the Doctor still had life and regenerations left. He would be the one to stretch the legends of Gallifrey across time. Someone to hold on just a bit longer.
The Master's final act was selfless. Something so self-sacrificing, just like the Doctor. Just like the way the survivor of the Time War had taught him.
But even in his final minutes of being dragged back into the Time War and into the time lock, the drums were beating. The never-ending drums. The link back to what the Doctor probably called home. Back to Earth. And he would feel the Doctor. Feel the despair and willingness to die, the readiness to give his life for one old human man.
Still, with his last breath, the Master knew that the Doctor would survive. He had to; he had better. His only selfless act from his life-long teacher shouldn't go to waste.