Title: Ninety-Nine And A Half Percent Human
Author: Zath Chauvert
Summary: The TARDIS is having technical difficulties, and there's something strange about one of its new passengers. A vaguely silly one-shot crossover between Doctor Who and the BBC's Jekyll.
Rating: PG or K+
Feedback: Yes, please! Any and all feedback, positive or negative, would be greatly appreciated. Just hit the Review button at the bottom of the page.
Disclaimer: None of these characters are mine. They all belong to whoever holds the rights to their respective shows. I do not intend to infringe on those rights or otherwise profit from this story in any way. I only wrote it as a means to make the voices in my head shut up for a little while.
Author's Note: This story won't make any sense unless you've seen the BBC series, Jekyll, so go watch it if you haven't already. Trust me, the show was written by Steven Moffat, so you'll have fun. Also, this is only meant to be a one-shot. At this time, I have no plans to write any sort of continuation. In the extremely unlikely event that someone wants to take this idea and run with it, please feel free to do so. All I ask is that you let me know so that I can read it too.

Ninety-Nine And A Half Percent Human
By Zath Chauvert

The Doctor was beginning to get frustrated. He was no closer to finding the source of the TARDIS's mysterious power fluctuations than when he had started. As far as he could tell, the drain was not occurring at any one point, or even at any group of points. It seemed to be evenly spread throughout the entire system. After four hours of work, he couldn't even figure out where it was going. Energy shouldn't be able to just vanish like that. Somewhere, something was consuming the TARDIS's power in split-second bursts at seemingly random intervals, and as long as the problem persisted, they couldn't risk attempting to travel again. Unfortunately, that meant they were stranded smack-dab in the middle of one of the emptier parts of deep space until it was solved. The Doctor hated to admit it, but his total lack of progress so far meant that they might be stuck there for a while unless the situation changed, bringing new information to light. Therefore, when the opportunity arose, he welcomed the respite provided by an interruption. With luck, a brief distraction would allow him to approach the problem from a fresh, more productive, perspective when he returned to it.

"Uh, Doctor?" The tone of Martha's voice told the Time Lord that she wasn't just looking for idle chitchat. He looked up from the from the control panel that he was running diagnostics on and saw his current companion backing towards him through the door, apparently unwilling to take her eyes off of whatever she was watching.

"Yes?" he said as he re-closed the panel and slid his sonic screwdriver into a coat pocket, giving Martha his full attention. She looked worried, but she didn't look quite worried enough to imply that there was immediate and unavoidable life-threatening danger close at hand. "What is it?"

"It's about the Jackmans." When Martha paused, the voices of the married couple that they had picked up on their last visit to London could be heard drifting in from the next room. The words were too indistinct to understand from a distance, but it was obvious that a semi-hushed argument was taking place. Martha finally turned and met the Doctor's gaze. "You said a while ago that the TARDIS recognized Tom as being part Gallifreyan. Exactly how large a part did you mean?"

"It's so miniscule that it's barely worth mentioning. He's ninety-nine and a half percent human. If we don't tell him about it, he'll never have any reason to even suspect that his family tree has an alien in it eight or nine generations back."

Martha looked through the door again and frowned. "Are you sure?"

"Absolutely certain. Without a copy of the Gallifreyan genome to do a side by side comparison, anyone studying Tom's full genetic profile would only turn up what appears to be a few minor mutations here and there, nothing of consequence. He's anatomically human, and he should have a normal human lifespan, barring accidents or foul play, of course. His brain might be wired to have slightly better memory than usual, but that's about all. You didn't seem concerned when I first told you. What changed?"

"He did," she said, pointing.

"What do you mean?"

"I mean that he just regenerated a few minutes ago! The power started going funny again, and when the lights came back on, he was different, almost someone else!"

"That shouldn't be possible."

"Tell that to the man who's now taller, thinner, and younger," Martha muttered, half to herself, as the Doctor hurried past her to peek through the door. "And," she said, "I should probably add, suddenly damn creepy, too."

"Oh dear," he said quietly, observing the scene playing out in the next room. "At least one of them isn't taking it well, hence the argument. Hopefully a quick overview of basic Gallifreyan biology will help them deal with the shock."

"Actually, if I had to guess, I'd say that this has happened before. Neither of them looked surprised at all. Claire just sighed and told him to behave himself or he'd lose his nudity privileges with her for a month."

"I'll go give them that biology lesson anyway. Even if they know what is happening, I doubt they know why it's happening."

Martha still looked worried. "Just be careful, alright?"

"This is Tom and Claire Jackman we're talking about," he said with a dismissive laugh. "It's not like either of them is the type of person that would hurt anyone without a good reason."

"I'm not so sure about that, Doctor. As soon as he regenerated, Claire started calling him 'Billy,' and their argument didn't start until she listed 'no killing anyone' as one of the terms of good behavior."

The Doctor looked at the control panel he had so recently been working on and sighed. He really didn't want to go back to that just yet. Then, he looked through the door again, weighed his options, sighed again, and said, "I'll take my chances. Hopefully, the promise of Mrs. Jackman getting naked later will be enough to keep me alive." He put on his most boyishly charming smile and headed towards the arguing couple.

The End

Another Author's Note: If you are upset that I never bothered to explain what was causing the power fluctuations, then you clearly ignored my advice and read this story without having seen Jekyll first. Shame on you. Go watch Jekyll!