"Well," Romana declared. "This is just perfect."
She didn't let go of the gyroscopic stabilizer until the TARDIS had finally stopped threatening to shake apart and the time rotor column had stabilized back into its normal grinding pulse. By that point, about half a million bars of flux radiation had gone through the stabilizer and into her hand.
"Romana!" The Doctor's eyes looked ready to pop out of his head. "I can't believe you just did that!"
She stared back at him, and for just a moment it seemed that she'd finally been left speechless. The moment passed very quickly.
"Well. I can't believe that you just flew us straight into a neutron inversion! Would it really have been too much work to include the most basic safety parameters in your navigation system?"
"It's a randomizer!" the Doctor exclaimed. "It wouldn't exactly be random if I'd put all sorts of parameters into it!"
"Yes, well, it would be a great deal less lethal! Honestly, how reckless can you possibly be?" She'd been holding her hand away from her as if it were covered in some sort of contagion, and the radiation wasn't already seeping through the rest of her cell structure. Now, realizing the pointlessness of the act, she let it drop to her hip. "This is ridiculous! I'm not even a hundred forty! I could have had another good century or two with this body, but then you come along and suddenly it's death around every corner!"
"Oh, come on now!" The Doctor looked genuinely affronted. "You can hardly blame me for all that. It's the price for being out in the galaxy!"
"I most certainly can blame you. Given the sort of utter recklessness with which you approach every single encounter, it's a wonder I haven't died sooner. Oh!" She blinked, raising the less-irradiated hand to her head. "Speaking of, I think the radiation's gone to my nervous system. Terribly dizzy all of a sudden."
"Well, that's quite a rapid onset, isn't it?" asked the Doctor. "I suppose it can't be helped, with your constitution. Might want to fix that with your next body."
"There is nothing wrong with my constitution! And I happen to quite like this body!" She sighed. "But yes, I suppose it can't be helped. Where's your Zero Room?"
The Doctor opened his mouth, then stopped, frowning off into the distance.
Romana gaped. "Oh, don't tell me you haven't got a Zero Room?"
"I don't know; I've never thought about it." Romana directed such an astonished glare at him that the Doctor actually recoiled, and his thoughtful tone became stridently defensive. "Look, I have more important things to do than keep track of every room the TARDIS doesn't have."
"You've regenerated three times in this capsule! How does someone go through three regenerations without a Zero Room?" Romana shook her head. "Although come to think, it makes perfect sense. You take such an irresponsible approach to every other aspect of your life; why should death be any different?"
"Irresponsible!"
"It has been well documented that regenerating without proper environmental controls can lead to wildly unpredictable results! Physiologically, you're lucky you still have hands, and psychologically, well…." She gave him one of her haughtiest looks.
"I like unpredictable!" protested the Doctor. "What's the fun in knowing exactly who you're going to be for the next hundred years? You know, Romana, I think you could benefit quite a bit from — what are you doing now?"
Romana's hands were darting over the controls at two separate workstations, and she was focused so intently that she hadn't glared at the Doctor for several seconds now. "Adding a Zero Room," she said.
"Don't be ridiculous. A Zero Room needs a delicate balance of hyperdimensional architecture; you can't just program one out of nothing."
Romana hmphed. "Well perhaps you can't. But it's really just a simple matter of recursive hyperprogression. The sort of thing you might have learned at the Time Academy, if you'd actually paid attention in your studies."
"Oh, not this again," the Doctor scoffed. "Tell me you don't really still believe that your silly Triple First is actually some sort of substitute for practical experience in the universe."
"Academic achievement is not silly," Romana retorted. "And are you still going to pretend that you might not benefit from a proper understanding of how all this equipment you use so carelessly actually works?" She gave the console's master switch a satisfied flip. "For instance, now you have a Zero Room. The next time you have to regenerate — which I expect will probably be soon — I'd suggest you give it a try. Your next body might be a bit more stable!"
With that, she swept out of the control room, the Doctor following her down the hallway. "Yes, well, I hope your fancy Zero Room can make your next regeneration a bit less insufferable!"
"So do I!" Romana shot back. "Otherwise I don't think I could stand much more of this, radiation or not!"
She disappeared into the a door that hadn't existed the last time the Doctor came down this hall — in fact, he was fairly sure the hall hadn't existed for a while, either. With a shake of his head, he turned and went back to the control room, checking to make certain Romana hadn't done anything else to his TARDIS, like scrub the entertainment channels or turn the randomizer off.
"You don't think I'm reckless and irresponsible, do you, K-9?" he asked, glancing at the less judgmental of his companions.
K-9 could only manage a garbled squawk in response. Then, after wiggling his antennae back and forth for a second in thought, he vigorously nodded his head.
"Oh, be quiet," the Doctor said.
Author's note: I understand that there are about 27 different semi-canon explanations for Romana's regeneration, and this story comports with none of them. It's just an idea I needed to get out of my head.