"Clara! If you keep gawking like this we'll never get a good spot to see the stage!"

It was nearly impossible for Clara to pull her attention away from the shining monorail tracks that floated miles above her head.

"Those-those are just...I mean...wowza," she said. She quickly pulled out her green phone to snap a picture.

"Yes, yes, 31st Century. Anti-Grav Rails. Cover the whole planet."

"The WHOLE planet!?"

The Doctor stopped and smiled. Despite his desire to get closer to the stage, he did always love giving a history lesson."

"You bet. Transportation that covers the entire planet. You live in Wales and wanna check out the pyramids at lunch time but still wanna make it to a baseball game in Boston by the evening? It's all possible with the Anti-Grav Rails. And all at low, low, prices. Well, low for the 31st Century, anyway."

Clara's imagination went wild. She would love to live in this time, being able to see every place you've ever wanted without worrying about having the time or money. Though, she could easily do that now in the Doctor's strange, wonderful blue box.

"Incredible," Clara snapped a few pictures on her phone.

"Absolutely, though despite the fact that they conquered gravity, the human race is still awful at keeping the trains on time," the Doctor flicked his wrist up to glance at his wristwatch, not more than a second later, a dark, silver train slid across the track without a sound, casting only a shadow.

"See," the Doctor said putting his watch in Clara's face, "the 3:25 from Moscow to New Jersey is 4.8 seconds late."

"Ah, yes," said Clara pushing his arm away, "what an outrage."

"I know! Still, an impressive feat of human ingenuity nonetheless."

All around Clara and the Doctor was a sea of excited humans whose attentions were all on the simple stage with a giant screen floating behind it. Projected on the screen was a gaping hole in the Earth that looked, to Clara at least, like someone shot a massive cannon ball that plunged straight into the planet and didn't stop until it punched through the other side.

"Doctor, what is going on today?" Clara was now shooting a video of the massive crowd. The faces represented people from every country in the world.

"Unity Day!" The Doctor said, excited to give another history lesson, "of course it won't be called that until many, many years later. It's the day the Silurians and the human race finally merge into one peaceful group and share this planet."

"A Silly-what?"

"Silurians, homo reptilia, they were the dominant species on this planet while your ancestors were still swinging around the trees and trying to perfect the art of walking on two legs."

"And they've been underground this whole time?"

"Yes," the Doctor said, rather succinctly. Clara had spent enough time with the Doctor to know that his short answers to her questions were usually hiding his real, longer answers to her questions. Before she could find out more, she bumped into a young man, not much older than her, in the crowd.

"Whoa," he said, pointing at her camera, "frost antique."

"Uh, thanks?" Clara was hoping "frost" was a good thing.

"This whole vint get-up you've got, it's very frost. Real shway. Pic?"

"Oh, well, if you insist," it was definitely a good thing, Clara thought as she struck a pose for the young man. She noticed the Doctor had started to wander through the crowd not far from her.

The Doctor had heard a voice. A very distinct, familiar voice. A pair of them, in fact.

"-can't believe you're making me witness such an incredible moment in history and won't let me write a story about it!" the first voice, a woman's said.

"Now, Sarah-Jane, that is not true at all. I'd be thrilled if you wrote about the plight of the Silurians that are still living beneath the Earth back in your time."

"Yes, excellent idea, Doctor. I'll call up my editor and tell him I've got a breaking story about lizard people who live under the ground."

"Hmmm, yes, well, you should try working for a paper that is a bit more open-minded."

The Doctor staggered back. He thought as hard as he could. It was simple for something to get lost and forgotten in over a thousand years of memories, but this day in particular...he was certain he...

"Doctor," Clara grabbed the Doctor shoulder, "I think I just met the 31st century version of a hipster."

"What? A what?" Clara had never seen the Doctor look so surprised, so confused and uncertain before. She looked over his shoulder and saw a young woman in a dark green power suit that looked like something from the old fashion magazines she found one day while looking through a box of her mother's old things. The man who stood by her side had a head of curly white hair and wore black velvet suit with red trim. The man had a face that oozed authority, but that was shattered by the gentleness of his smile.

"Doctor," Clara asked, "do you know that man."

"That," the Doctor began "is Sarah Jane Smith."

"Wait, the journalist? I used to read about her in school, she's amazing...but what's she doing here?"

"The answer to that probably has something to do with who the gentleman is that she's with?"

"The silver fox?" Clara said with a smile.

"The...the what?"

"Nothing."

"That's me."

Clara looked at the Doctor, then at her Doctor, then back at the other Doctor.

"I have so many questions and I don't know where to begin."

"That's how I looked many, many years ago. I'm only about 500 there."

"So, you've been here before?"

"No," the Doctor said softly, "I haven't...or at least, for some reason...I don't remember ever being here before."

"This probably isn't good then, is it?"

The Doctor shook his head.

"Clara, this is beyond not good. This goes right into very, dangerously, universe threateningly, paradox inducingly, bad."