The Doctor grabs him, and their minds connect in ways humans can't possibly understand.
Time slows down, because time always does in the mindscape, and because they are Time Lords, Lords of Time, ruling over it, not the other way around.
They are standing on a wide field of red grass, and the Master is surprised to note that both of them are wearing the looks of their current regenerations.
He folds his arms. "What is it now, Doctor?" He spits the name like a curse.
"I -" The Doctor turns to the side, running a hand through his hair.
"You what?"
The Doctor seems to struggle for words, then turns back towards the Master. "Just regenerate. You can't let yourself die, we both know that. So just - just do it!"
He crooks his head and a smile crosses his lips. "Oh, my dear Doctor, was that a challenge I heard?"
"No!" The Doctor goes pale. "No, no, but - You are you, I know you. You're going to regenerate. You're going to."
The Master waves his hand, and a chair for him to sit on appears. He sits down, leans back. "Who are you trying to convince, huh? Me, or yourself?"
No answer.
He leans towards his oldest friend. And enemy. "Tell me, Doctor, why would I? So you can keep me as one of your pets? No, thank you. I much prefer death."
There is a flash of pain in the Doctors eyes, as if the Master had just slapped him (only without the defiance). But he pulls himself back together.
"Because you can't give up on yourself. You never could."
Now the Master throws his head back and laughs. Loud.
When he calms down again, the Doctor is frowning.
He snorts again at this confused look. "Oh, you really think that's it? That all those centuries -- I gave up on myself back when we first left Gallifrey." He laughs again, but this time it's bitter. "All this time, and you didn't even notice."
The Doctor's frown deepens. "But then why?"
"Because the one thing I could never give up on, that I didn't even want to give up on, was you."
The Doctor flinches, opens his mouth, then hangs his head and says nothing.
"That entire year?" The Master says, making a swiping gesture with his hands. "That entire years was built on nothing but a cheap trick. A way to say hello. And you let it work!
"Tell me." His voice is dark now. "How far has the mighty Doctor fallen?"
He swipes a hand. Suddenly, the Doctor is sitting in another chair, and cuffs are wrapped around his hands and feet.
"And, see, this" Another motion of his hand, and people start appearing. So many people. Some the Master recognises, some he doesn't. Faces, young an old. Companions. Victims. He sighs. "This shouldn't be half as easy as it is. Your mental defenses are wracked, Doctor. I can link right into your memories, pull all this" - he makes a sweeping gesture at the figures - "Out of it without encpuntering resistance. I can do to you whatever I like as long as we're here and you wouldn't be able to defend yourself. Rassilon, I could kill you right now."
The Doctor looks at him, and that defiance is back in his eyes. "Then do it. What are you waiting for?"
The Master jumps to his feet and starts pacing, his own chair disappearing. "Did you listen to a single word I said? I. Am. Not. Trying. To. Defeat. You."
And now hope dares to creep into those eyes as well. "You're not?"
"Oh, you're deaf as well, now. No, I am not. Why bother? I'm gonna be dead in a few minutes. Besides, you are not fun at all like that, just falling right were I want you."
The Doctor flinches again. "But you don't have to die. We could still fight across the cosmos. We could -- Wherever you wanted. Just not earth."
"What?" The Master raises an eyebrow. "And you would allow that after all I did?"
The Doctor sets his jaw. "If you swear an oath to stay away from earth, and if this is what it takes to get you to survive, then yes. I would."
The Master titles his head. "Mh. Pitty. But not enough." He leans in closer. "Tell me, Doctor, how much am I worth to you? How much would you give so I would survive?"
His answer is silence, and again he laughs, but it's dark, and bitter now.
"That much?" he asks, his voice laced with sarcasm. "Wow, Doctor, I am impressed, I really am. I thought I'm at least worth a hairclip, don't you think?" He straightens his tie, and looks at the Doctor again, freeing him with another sweep of his hand (the memory figures he had called had disappeared a while ago, but neither Time Lord had noticed.) "Well then, if you'll excuse me. I have a death to die."
And from one moment to the other the Doctor is talking like his life depends on it (in truth, it's not his own, it's the Mater's, and they both know it). "No! Wait. Please.
"Please, Master." (The Master allows himself a small, satisfied smile at this.) "You can't -- You shouldn't -- You're not supposed to leave me. If I'm alone again, I don't know what I'll -- the first time I almost lost my mind, but --"
"What." The Master interrupts him, and this time the emphasis is that of a sentece, not a question. "Would. You. Give. Up. For. Me?"
There's another beat of silence, and just as the Master is about to leave for good, he heard the Doctor's voice, quiet, weak, hoarse. "Eveything."
He halts in his steps and turns back towards the Doctor, raising one eyebrow. "Everything? Even your precious earth?"
The Doctor tenses, but doesn't protest.
"Or your cute little girlfriend? What was her name again? Martha Jones, was it?" He pauses, tapping his chin. "Oh, but humans are no fun. The freak, though - I imagine I could be entertained by him."
The Doctor slumps even further, then, after a moment straightens, determination in his eyes. "No."
"No?"
"No. You didn't give up on me, but I can't give up on them. Don't try to make me."
The Master smirks. "So we're finally getting somewhere." He turns back around, away from the Doctor. "Stop me then."
He pretends he can't feel the relief flooding through the Doctor's mind, making the whole mindscape shake, and then exists.
And allows himself to regenerate.
The blast of energy is strong enough to throw the Doctor to the other end of the room, and despite this incarnation being so very short-lived it's surprisingly painless.
When he blinks, it's with new eyes - and new ears, and new hair; new everything. Except that mind, that is still the same as ever.
He titles his head, grinning at the Doctor again. "Well then? Come on! Stop. Me."
With that, he thrusts his hands in his pockets and presses a button on the (now modified, improved) vortex manipulator he keeps there. One moment later he is standing in a field of silver grass, coloured just as the leaves on Gallifreyan trees, the freak unconscious a few feet ahead of him.
He takes off the vortex manipulator and crushes it with his heels. It would allow the Doctor to trace him, and he has his own devices tucked away here.
Keeping the good Captain under control would be a problem, but he inserted a remote controlled chips into his brain a few weeks ago, so that all it takes is the pressing of a button to kill him again.
Looking around, he mentally maps out the place and then start walking to where he knows his 'precautions' are stocked.
He grins, and opens his telepathic connection to the Doctor again, just long enough to send a message through before letting it fade back into a pleasant background hum.
"Let the chase begin."
I'm not sure I'm really happy with this, but whatever. Feedback and constructive criticism please!