Not being the most observant Time Lord in the universe, it was a while before the Doctor noticed. Oh, he noticed that he'd regenerated; death by laser really ihurt./i And he noticed that he was a woman now. Well, he did once a button pinged off of his shirt under the strain of his new breasts and took out the nearest Dalek. But he was back on the TARDIS, rooting through the wardrobe room for some female clothes that weren't from 1975, before he caught sight of his reflection, ginger hair and slightly wonky nose included.
"Oh, no." He'd regenerated into the spitting image of Donna Noble. "Please, no."
It was the guilt, he decided. His subconscious had obviously decided to give him a semi-permanent reminder of his violation of Donna's mind. Thank God his previous incarnations had been less guilt prone; otherwise, he would have spent a lifetime running around looking like Adric.
Looking on the bright side (this incarnation was clearly one of life's natural optimists) he thought that Donna might have left some of her clothes around the TARDIS, which would at least spare him the indignity of trying to squeeze into one of Zoe's catsuits or Leela's leathers.
The Doctor was hanging around the vortex, making the pockets of Donna's leather coat bigger on the inside and trying to get used to thinking of himself as a she now. Curse humans for not having the foresight to come up with a word to describe someone who'd been male for ten lifetimes but suddenly found themselves female on the eleventh.
She'd just finished repairing the sonic screwdriver after she'd sat on it (clearly the back pocket of her jeans was not the place to keep it) when the distress signal came through. The Doctor stood up, dropped the sonic screwdriver into her pocket and tossed her hair over her shoulder.
Now or never.
The Doctor had to question the evolutionary wisdom of carrying your brain in your hands. It made you very easy to conquer. She liked the Ood, she really did, but there were only so many times a species could get itself subjugated into slavery before you started to lose sympathy.
"The DoctorDonna has saved us again."
"No, no. Not DoctorDonna. Just Doctor, just the Doctor."
"The DoctorDonna has saved us again," the Ood insisted.
"Oh, do shut up."
In the back of the TARDIS the Doctor found the key of Rassilon, the missing preface from the Earth bible and a pair of carnivorous shoes, but she didn't find a single one of Donna's bras. Where had Donna kept her underwear? Where had Donna bought her underwear? Why had she never asked Donna about her underwear when she lived here?
The trouble was the running. There was a lot of running in the Doctor's line of work and although this body's cleavage was very useful for distracting megalomaniacs right before they activated their doomsday weapons, it just got in the way when it came to running.
The Doctor was a genius. She was the cleverest person in whatever room she was standing in. She was more than capable of figuring out female undergarments on her own.
"Doctor Martha Jones speaking."
"Martha, where do you buy your underwear?"
"Jack! Jack! Get over here!"
The Doctor hung up the phone with the nagging feeling that perhaps she shouldn't have used that Dalek voice box to disguise the fact that her voice now sounded uncannily like Donna's.
"Brigadier! It's the Doctor. Do you know anything about women's underwear?"
The Doctor walked through Cambridge with her head held high. Her visit with Liz Shaw had been most instructive. She now had a bra that fit and the knowledge that this body couldn't wear miniskirts.
She had also learned that people at Cambridge frowned on you pretending to have doctorates. You learned something new every day.
"We should kill it."
"Hang on a sec-"
"We'll have nothing to worry about once it's gone."
"Out the airlock. Even aliens can't survive in space."
The stupid, stupid twenty-second-century humans wouldn't listen to the Doctor trying to talk them out of throwing the fabulous, brilliant, brand new life form they'd just discovered out into the vacuum. No amount of reason, fast talking or reasonable fast talking was getting through to them.
Not knowing what else to do, the Doctor took a deep breath and shouted, "Oi! Earthlings!"
The Doctor was sulking, as was her occasional wont. Early twenty-first century Earth was her favourite place in the whole wide universe and now she couldn't go there for fear of running into somebody she knew and having to explain her uncanny resemblance to Donna Noble.
Instead she was stuck on New Earth watching the fireworks at the carnival of the quadruple millennia. Boring.
"Doctor!" a female voice rang out through the crowd.
The Doctor turned round in surprise. Who did she know at this time on New Earth? If it was a cat nun, she was leaving.
"Doctor, you only went to get some fireworks. What could have possibly happened to cause you to regenerate?"
"Hello, Romana," the Doctor said with a smile. And there was Romana, all dark curls and arched eyebrows.
"Oh. You're a future regeneration. Doctor, you should know better than to cross your own time line."
"I'd forgotten we ever came here. This was just after we found the Key to Time, wasn't it? That was a bit brilliant of us."
"And you're female now. Doctor, didn't you pay any attention in regeneration studies class?"
"None whatsoever," said the Doctor with a grin. "You'll always be much better at it than me. Apart from your third regeneration. I was never wild about your third regeneration."
"I'll leave now," said Romana. "Before you can tell me anything else about my future."
"Bye, then," the Doctor called after her. "Be magnificent!"
The Doctor's favourite thing about her new regeneration was that she could now think about Gallifrey without getting all miserable like the big bloke in leather, or genocidal like the long streak of nothing. Sometimes she frowned a bit when she thought about the other Time Lords, but she tried not to. She'd only had this body five minutes and she'd prefer not to give it wrinkles.
"What's your name?" asked the girl the Doctor was strongly considering accidentally-on-purpose kidnapping as a new travelling companion. She had worried briefly that now she had a female body she'd have difficulty convincing bright young girls to travel with her in the TARDIS. It transpired that there was nothing to worry about; she just attracted a slightly different kind of bright young girl.
"That's not a name. That's a job. What's your name?"
"Doctor Joan Smith."
"Don't be silly. No one's called Joan Smith. That's like being called Jane Doe."
"Fine. Donna Noble, that's a real name. Doctor Donna Noble."
"Suits you, Doctor Donna."
"No. Really, no. Just call me the Doctor. What's your name, anyway?"
Months later, the Doctor left Jane on a small planet on the edge of the Milky Way where she was enjoying a rather sordid affair with the Queen that would go down in the planet's history as the stuff of romantic legend.
The Doctor was considering the best place to pick up a new companion (early twenty-first century Earth might be fine as long as she steered clear of Greater London and Cardiff) when she stumbled across a couple of Daleks. And by stumbled across, she meant that two Daleks made a concentrated effort to kill her.
Was there a 'Get Out Of Genocide Free' card that the Daleks were passing around among themselves? It seemed as though she always missed one or two. Which was unfortunate, because the surviving Daleks had consulted among themselves and decided that there would be far fewer attempted genocides if the Doctor was exterminated for good.
The result of this democratic decision was that the Doctor had to hide. She had a few different options of where to go. There was the end of the universe, where she'd probably end up making a space ship out of food; the beginning of the universe, where nothing at all of interest happened; or Earth, where she'd probably end up falling in love with a school matron or something. The Doctor decided to go for the third option, after taking a few precautions. She set the TARDIS for the late 1960s, stored her Time Lord conciousness in a fob watch and regressed her body to infancy.
The 1960s would be brilliant, she decided. It would give her enough time to grow up and open the fob watch in time for the really interesting alien invasions of the twentieth century. Plus, it was sure to be full of really lovely sixties couples like Barbara and Ian who were just dying to adopt a baby.
"Your daughter, Mrs Noble."
"Donna, we decided on Donna for a girl, didn't we?"
"She's got ginger hair. She's not going to look much like us."
There wasn't a fob watch to be opened. Sylvia sold it at a car boot sale in 1979 to an American Torchwood agent by the name of Jack Harkness. Donna Noble might have lived and died as a human if not for making the somewhat foolish decision to marry a man who only wanted her for spider bait. This resulted in her meeting the Doctor and becoming the most important woman in the universe. Which was lovely.
The Doctor was quite correct in saying that a Time Lord – Human metacrisis would kill a normal human. But Donna was a Time Lord who'd chameleon arched herself into a human, and as he took her face in his hands to wipe her memory she came back to herself. The Doctor looked into the eyes of her previous regeneration and tried to think of the best way to explain the situation.
She pretended to faint dead away. It was probably for the best.
The Doctor blathered mindlessly into her, Donna's, mobile phone. She really hoped that it wouldn't ring and let everyone know she was talking to thin air.
"Donna, I'm just going," said her previous incarnation. The stupid, skinny one. Oh, and he was turning the big, sad eyes on her. Ah, never mind, he'd be fine. Give him a couple of decades and he'd regenerate into her. Then he'd be brilliant.
Anyway, telling him that he was technically his own best friend would only upset him. The Doctor put her phone away and tried to remember where she'd parked the TARDIS.