It had been another long, emotional day for the Doctor. As he flew threw the sky in his little blue police box, a box which anyone who saw, inside and out, must make the obvious but befuddled statement, "it's bigger on the inside than it is on the outside." As the Doctor frantically pulled levers and pushed buttons, all seemingly calm, a million and one things flew through his mind, as usual. After he'd left Rose with her mother for what, he assumed, was the very last time, he wondered what he was going to do with the rest of the eternity he had to do whatever he pleased. For you see, that's the thing about being immortal; you have literally forever to do nothing. He was sad, though he wouldn't admit it, to be travelling time and space, alone again. His heart always seemed a little empty whenever he was without a companion, though he always made a resolution whenever he lost one not to look for another.

Suddenly the Blue Police Box landed with a very loud *THUD*, and the whole place shook momentarily. The Doctor's bright ever-thoughtful brown eyes shot up, then to the door. Looking down at his pin-stripped brown suit and brown tie, adjusting his tie, then running his fingers through his ever-disheveled brown spiky hair, he ran to the door of the Tardis, swinging open the door with a flourish as he wondered what would be lying on the other side. But as soon as he had seen what lay on the other side of the door, he quickly wished he'd left it firmly closed, because staring him right in the eyes were about six Lacerta. The Lacerta are a generally peace-loving people, except when they have their eyes set on taking over your planet, intent on turning it into a breeding ground for their over-abundant population. 

He'd heard of them before, had met a few in his travels, but the Doctor had a feeling that this small group of Lacerta weren't here for a party, and as they held up their electro-rays, aiming right for the Doctor, he realized that his feeling was correct. The Doctor ran out of the door of the Tardis, slamming it tight behind him and taking off out of the nearest exit. 

The Doctor quickly surmised that he was in the back of a large warehouse-like brick building, and turning on his heel, he took off down the nearest alley. Rounding the corner, he could here the lizard-like people in hot pursuit, their feet pounding on the concrete, their nails scratching each time their feet landed on the concrete. He wiped his brow with the sleeve of his jacket, both hearts pounding as he ran. As he rounded the second corner, he heard the thump-scratch of the Lacerta's feet stop suddenly, and then retreat. When his brain registered he wasn't being chased anymore, he slowed to a jog, looking over his shoulder to make sure they weren't still in pursuit. Turning his head forward, he slammed into someone, knocking them to the ground and losing his balance at the same time. 

In front of him sat a terrified looking little blonde woman, attractive, early to mid 20's. Straightening up, he reached his hand out toward the unknown young woman, hearts still beating heavily, and pulling her to her feet with a breathless, "I'm sorry." The young woman stood up straight, stature obviously a point of contention with her by the way she stretched her fit torso to accentuate 

Remembering suddenly why he was running in the first place, he grabbed the girl by her elbow, pulling her into a quick jog, a million thoughts running through his mind. "Where are we? What year is it?" he asked as they ran, ducking into a small brick building, pulling her in as well, and leaning against the door, breathless.

(Sorry if it was a bit short, there wasn't a lot of backstory to be written.)