“ … Congratulations,” the Master retorts, aiming for bitter, and landing somewhere on the terrain of feisty: with a perceptible quiver in his tone.
“It’s been too long old friend.” The Doctor said as he approached. His converse squeak on the floor as he did so. “You know I cant let you do this. Right?”
“Do WHAT?”
The word ‘friend’ chafes visibly. The Master strives to conceal it with crisp enunciation and expansive gestures; it’s really very primitive, the urge to make oneself larger at sight of a threat. And what threat the Doctor poses is far more obscure, far subtler, than a gun or a poison. It’s the threat of vulnerability.
“Oh, right. I suppose you’ve no notion of where I’ve been. You’re still a young face. The one who almost had me. The one I MISS.”
He thrusts that last word like a gauntlet, wondering if he’ll ever have the fortitude to tell this young, eager, simperingly apologetic martyr of a Doctor what happened after he stumbled into the Timelock with the intent to murder Rassilon. Does the Doctor even notice the silver in his hair now? The new wrinkles? The more bitterly fermented weariness?
“We are a long way from that Christmas when I made the entire earth into my image, my dear. In your future, I will be thwarted still more profoundly, but not by your hand. No. By my own: in another face.”
By the only person I EVER trusted, after you LEFT me. Oh, Missy.
“I scarcely have the strength to live, much less concoct a scheme to conquer the universe. I’ve lost my touch, darling. So you can relax, and go.”
Damn that porcupine hair; damn those soft dark eyes; damn those squeaky shoes. Damn him whom he loves.