insane master fan

And halfway through the season they encounter the Master, who's in the middle of some impossibly elaborate scheme to obtain an ancient superweapon or reality-ending device or whatever this week's apocalyptic obsession happens to be.

The Doctor slowly pieces together that something suspicious is going on, starts dismantling the plan as Doctors tend to do, and eventually the Master gets fed up and decides it's time for the dramatic reveal.

"So," they say, pulling off the disguise with the biggest grin imaginable. "It's me."

The Doctor just blinks.

"...Who are you?"

The Master laughs.

"No, come on."

"No, seriously."

"It's me. The Master."

"I'm... sorry?"

"The Master."

"...Should that mean something to me?"

"Oh, very funny."

"No, genuinely."

"You always figure it out by now! Usually I accidentally say one thing slightly too dramatic and you're immediately all, 'Master!'"

The Doctor just shrugs apologetically.

"I really wish I knew what you were talking about."

"...No."

"...Yes?"

"...You're serious."

"...I think so?"

The Master just stares for a long moment before pressing something on their wrist communicator, and muttering, "Cancel the death weapon."

"...The what?"

"The death weapon."

"You had a death weapon?"

"Yes, but that's not important anymore."

"I feel like that's actually incredibly important."

"I'll build or find another one. There are billions of apocalypse devices in the universe. I can get another. What I can't get is an explanation for why my oldest friend nemesis has apparently factory-reset to not knowing me. Me."

Then the Master spends the rest of the season still doing deeply questionable things on the side because they're still the Master, but their actual objective quietly shifts from conquering the universe to figuring out what happened to the Doctor and who was responsible.

Every encounter becomes less, "Behold my latest evil plan," and more, "Right, yes, the evil plan can wait. Sit down. We're making a timeline."

"No, no, stop trying to foil the plan for five minutes. Tell me what happened. Who did this to you? This is frankly insulting."

"No. We are not continuing until you remember who I am and pin me against a wall in righteous indignation like you're supposed to. Especially after last time."

"...Why would you want that?"

"We don't have to get into that."

Meanwhile the Doctor is standing there completely bewildered because this terrifying stranger seems significantly more invested in restoring whatever bizarre relationship they apparently used to have than actually carrying out any of the world-ending plots they keep interrupting.

Eventually somebody asks the Master why they've abandoned a perfectly good opportunity to take over the universe.

The Master just looks at them like they've asked the stupidest question imaginable.

Something that's occurred to me. There's multiple versions of how the Master became Crispy, one of them that he tried to regenerate despite having no regens left

And I've been thinking, if he knew he was in his last body why did he try regenerating? Why not find an alternative?

Or heck, if he knew it was his last incarnation, he could have tried to find a way to extend his life before it got to the point where he was barely hanging onto life as Crispy

But what if he DIDN'T know that was his last body?

When I said it was birdseed she just went “oh- can they actually eat that? Is that safe?”

I didnt know how to respond like, at all, so I just pointed at the duck and said “bird”

Something something the master calling himself that because he desires control above all else. And the doctor being the one person he can never control. The doctor being impulsivity and chaos and unchainable. Then the master dies in his arms because dying is better than losing control to the doctor. Because dying is the only way to control the doctor,