What if the Doctor wasn't as alone as he thought?
Authors Note: The villain in this chapter is really non-essential, so I didn't bother giving him a name, species or even mention what his plan was.

The Doctor looked at his new opponent. A new enemy. He gave him a cheesy grin as this new mastermind explained his plan.
"That's very clever. Very very clever. Brilliant in fact. Oh." He said, then paused. "But that would be bad. Brilliant, but bad."
The man frowned at him. "You are very annoying."
The Doctor grinned. "I get that a lot."
"That's because it's true." Amy said behind him. The Doctor looked at her. He had almost forgotten her. Amy and Rory sat on two chairs, back to back, tied up in rope.
"What do you mean? I'm not annoying. I'm helpful and appreciative… and cool."
She scoffed. "Helpful? You know what would be helpful? Saving us!"
"Oh…right." The Doctor said, reminding himself of their impending doom. "Yes, I'll get right on…that." He stopped as the man pulled out a weapon. "Oh, a gun. Not good. Yes, definitely not in the category of 'good'. In fact I would go so far to say that it was in fact-"
"Shut up," the man growled.
"Okay, shutting up now." He said, then mimed zipping up his lips.
"Finally." The man said. "Now, you seem to be a man of science, Doctor. See this is a very special gun," he said patronisingly, as if the Doctor was just a child, instead of the millennia old Time Lord. To be fair, he didn't know that last bit. "It's a distinct design. Mixed with several very advanced technologies. They called it the Transdimension Laser."
"Ooh, good name!" The Doctor applauded.
The man narrowed his eyes. "Well we've never tested it on a live subject before, but we tested it on some other things, and they literally disintegrated."
"Ah, there's that 'not good' bit coming into it again."
"Exactly! Because I'm sorry, Doctor, but I do have places to be, worlds to destroy, you know." And he pulled the trigger. The Doctor shut his eyes. But the beam never made contact. First it seemed that it had hit an invisible wall, but then the wall solidified to reveal itself to be a young woman with pale skin and raven hair. She had her arms flung out, protecting the Doctor, shielding him. The beam stopped, and she fell to the floor in a crouch.
"What is the meaning of this?" The man demanded. "Who are you?"
She frowned at him. "Wait, you…you can see me?"
"Of course I can see you! Now who are you?"
She grinned at him with an evil glint in her eyes. "Your worst nightmare." She said, the pounced on him, knocking away the gun. She hit him over the back, hitting him into unconsciousness. There was a silence. The woman walked over to the gun, and pulled it apart.
"Ahh, there's your problem. You crossed these wires here. I bet if we took a look, those objects he mentioned weren't 'disintegrated', only put into a different dimension…Hence Transdimensional Laser. Honestly, you'd think that you'd pay attention to the name. It often has some clues. A toaster toasts bread. A Transdimensional Laser sends things into a different dimension… or in this case takes things out."
"Umm, excuse me." Rory said. "But uh, who are you?"
She turned to him with a grin. "My name is Safiavauzura. But you can call me Guardian, or Protector, or Ava… or Fred. Well not Fred. Romana's Fred." She laughed. Then froze. "You…you can see me. Rory…you can see me."
"Yeah so can I. Now can you let us out?" Amy cut in, annoyed.
Ava paused, then nodded. She sped over to them, quicker than they could see. In one quick action, she drew a dagger from her boot and had sliced the rope between them. Then she took a few slow steps back. The Pond's stood up.
"Right. Now that's done, who are you?" Amy asked.
"I told you. My name is Safiavauzura. I'm the last Time Lady in existence."