I just had this funny thought and I figured; what the hell, even if it is a bit OOC. Obviously this isn't meant to be taken seriously. I own nothing.
"I'm dying in your arms; happy now?"
"You're not dying; don't be stupid. It's only a bullet; just regenerate."
"No."
"One little bullet; come on."
"I guess you don't know me so well. I refuse."
The Doctor grimaces. He knows that mad gleam in the Master's eyes, known it since they were kids. Why the idiot has to be so deliberately perverse the Doctor will never know, but what he does know is that right now he has to find some way to convince the Master to regenerate.
Come on; think, think. What does he like?
Then, it occurs to him.
"I've got a swimming pool," the Doctor tells the Master, hiding the gleam of hope from his eyes because he knows the Master will just let himself die if he sees it.
For a moment, there is silence.
Then, the Master looks up at him and frowns. "In the TARDIS?"
Bingo. "Yeah, I do," the Doctor affirms with a grin. "Goes up to eighteen feet deep, diving board, water slide, whole nine yards."
The Master's eyes narrow suspiciously. "I can go in it any time I like?"
"Yeah, sure."
With a grimace and a sigh, the Master tosses his head. "What the Hell." The room is promptly filled with golden light.
Mission accomplished. The Doctor grins.