18th of March, 2000
London, The United Kingdom, Earth
"I suppose that note was genuine..." These were the words the Doctor said as she prepared her TARDIS for dematerialisation. She had escaped the Time Lords after her previous incarnation killed himself by jumping off of a pylon, but they caught up with her, leading to her current predicament: forced to permanently live inside of her TARDIS under the threat of total temporal erasure should she try to escape again. Although, a Time Lord who sympathised with her sent a note stating that the Time Lords lied about the dematerialisation potentially erasing her. She took the chance and... success! Now she was in the Time Vortex, seemingly fulfilling her punishment. As she was moving through the vortex, however, a current of sort sucked up the TARDIS and forced it through the dimensional wall, leading it to another Time Vortex she was unaware of.
"Woah, that was weird." The Doctor made some checks on her console to see if anything was wrong with it. "Nothing wrong. Wait... Am I still dru-" It was then that the Doctor puked on the floor. "Yup. Alright. Still a bit woozy." The Doctor went to her computer screen and saw where she was heading: London on Earth, exactly 28 years from where she left off. "Oh, that's lucky. Let's try to land there."
The Doctor, still in a bit of a drunken stupor, ended up exiting the Time Vortex too early and caused the TARDIS to hurtle towards Earth. She tried to steady the TARDIS, but couldn't stop it from what was going to happen to it.
18th of March, 2028
London, The United Kingdom, Earth
At Burgess Park, Martha was ready for a calm day in the park. Tom, her recent fiancé, was unfortunately sick with a cold, so he could not get to work. It was his request that she go out for a little while today, just to get a bit of fresh air. She got out her phone and called Tom. "Hey." she said.
"Hey, Marty." Tom replied on the other side, still at home watching the boxset of Hawaii Five-O, a police drama that lasted for twelve seasons from 1968, that Martha decided to get him for his birthday. "How's your trip out going?"
"Great. It's always nice to smell freshly-cut grass, even if the sky's overcast. And you?"
"Good outside of the sniffles. I'm onto the last season and I'm really hoping that Wo Fat gets defeated."
"So, was that a good birthday gift or not?"
"It's a really good gift. Thank you, Marty."
"You're welcome, Tommy. See you soon."
"See you." As soon as Martha hung up, however, a bit of the cloudy covering lit up before what looked like the Doctor's TARDIS went through it and crashed onto an open area of the park. Most people ran away, but Martha decided to have a closer look. When she got to the doors of the TARDIS, they burst open to reveal a raven-haired woman with deep brown eyes climbing out of it. Martha looked at the woman in confusion. "Who are you?"
"I'll tell you after you help me up." the woman said before Martha helped her get out of the TARDIS. The woman looked at Martha in exhaustion. "I'm the Doctor. Thanks for helping me."
"Umm... No problem. Could you stand there for a bit, please?"
"Okay."
Martha got a bit away from the woman at she could and decided to call UNIT. "Hello, is this CSO Kate Lethbridge-Stewart?" she asked once the call was picked up.
"Yes it is, Martha Jones." Kate Lethbridge-Stewart, Chief Scientific Officer of UNIT, replied, "What's going on?"
"There's a woman in Burgess Park who's claiming to be the Doctor. She's got a slight Scottish tinge to her accent, a smell of alcohol surrounding her, and a TARDIS similar to what the Doctor would use."
"Alright, we will be there as soon as we can."
"Thank you."
"Thank you for what?" the woman said after Martha hung up, spooking her in the process, "I've heard of this UNIT group before I was sent to the TARDIS."
"Will, they're just some people I think you may like."
An hour or so later, the woman was in the UNIT Building, sitting inside an interrogation room, with Lethbridge-Stewart, Scientific Advisor Shirley Anne Bingham, and a researcher by the name of Jo Jones. The TARDIS materialised behind them to their surprise, with the Doctor coming out of it. "Nice to see you again after only a few hours, Kate and Shirley." she said, "I know for you both, it's been a week, but time travel is funky that way." The Doctor turned to Jo. "Nice to see you again, Jo. My condolences to you for Clifford's death."
"Thank you." Jo replied.
"Now, who do we have here?"
"She's calling herself "The Doctor," Doctor." Kate began, "She was found by Martha Jones in Burgess Park this morning after a police box fell from the sky and caused a crater to form with no casualties. When we brought her in, she had the typical Time Lord physical attributes: two hearts, three brainstems twisted together like a rope, a thin film in her lungs to help with oxygenation, and more that I'm going to assume more stuff you haven't told me."
"No, that's all the generic differences between Time Lords and humans. Does she really call herself "The Doctor," Jo?"
"Yeah."
"Let me into that room."
The Doctor was let into the interrogation room. The woman was confused. "Who the hell are you?" she asked the Doctor.
"You from a different dimension." The Doctor replied, "In fact, you are the one that's from a different dimension. How'd you get here?"
The woman scratched her head. "I was sent to the TARDIS by the Time Lords, dematerialised said TARDIS, and was travelling through the Time Vortex when I felt this powerful gust hit her hard, and then I ended up here."
The Doctor knew what happened. "Doctor, you've fallen through a dimensional current."