Disclaimer: I do not own Doctor Who! If I did, this would be canon!

A/N:- This was what I wanted to happen when the Doctor said he would never have existed. And it also explains how River recognised the tenth doctor in the library.

"Something old, something new, something borrowed... something blue." Amy watched elatedly as the TARDIS, seemingly blue-er than ever materialized in the middle of the room.

"It's the Doctor. How did we forget the Doctor?" She heard Rory ask. But she ignored him, leaping up and over the table, and striding up to the time machine. She knocked almost frantically on the door, completely oblivious to the strange looks the guests were giving her.

"Okay Doctor! Did I surprise you this time?" She queried loudly, and the TARDIS door opened immediately to reveal the Doctor. But not quite the person she was expecting.

"Well, sort of. But then, you lot, you never cease to amaze me." He said, grinning around the room.

Amy stumbled backwards away from him.

"Who are you? Tell me, who you are, right now!"

"Oh... I knew I'd have this problem. It's me, Amy Pond. The Doctor."

"No your not. You might be wearing his clothes..." She paused for a moment, and the anger left her voice as she stared at what the man was wearing, "his raggedy clothes... but that doesn't exactly make you the Doctor."

"Oi, if you fell through a glass roof after jumping out of a spaceship, I think your clothes would be slightly raggedy too! And as for me being the Doctor, well, Amy Pond, let me show you! Number one..." He plunged his hand into one of the pockets, and brought out a sonic screwdriver. And not the green, clawed screwdriver she was used to seeing, but a smaller, more screwdriver-ish tool, with a bright blue light on the top. "My sonic screwdriver. You first saw me use it when I examined the crack in your bedroom wall. And then I ended up burning it out, trying to attract prisoner zero. Not the first time I've burnt it out... never try to increase the radiation levels in an x-ray machine in a hospital with a sonic screwdriver."

"Okay, so you've got the same sonic screwdriver and the same clothes, you could have just been spying on me!"

"Oh, why does no-one ever believe me? Right, what else? TARDIS, crashed in your back garden, star whale, Winston Churchill! Fish custard! Scary cracks in throughout time and space! Silurians, the Dreamlord, Vincent, Craig and Sophie, River Song, weeping angels! Oh! I know! Apples!" Everyone was staring at the man like he was insane, even Rory, who had come to the conclusion that this was the Doctor, and was now thinking that this guy was even more insane. Apples?

"What about them?" Amy asked quickly.

"The first thing I said to you. 'Can I have an apple?' And then, you told me that your Mum used to draw faces on apples for you. You gave me one, and about... ooh, five minutes later for me and twelve years later for you I gave it back to you when you'd trapped me in the door of that old guy's car." He grinned manically at her.

"Doctor. Oh my God, it's really you!" Amy rushed up to him and hugged him. Then she pulled away again.
"But how? I didn't know you were a shape changer."

"I'm not. Well... not usually. When I die, I regenerate. Change my body, every single cell is rewritten. Apart from my brain of course. Remember when I said I was still cooking? That's because I'd only just regenerated. That's why I had a new mouth. Although just to let you know, bananas are brilliant. Not fish custard, not in this body. Bananas. Good source of potassium. Always take a banana to a party. I invented the banana daiquiri you know. Few centuries early, but, oh well."

"You talk to much." Rory stated, coming to stand by Amy.

"Rory! Good to see you!"

"You too. Bu-ut you never answered the question. How are you, err, so different?"

"He regenerated, right Doctor?" Amy shook her head at her boyfriend, thinking he was occasionally, just a little bit slow.

"Well, actually I didn't. You see, you might have remembered me, but I still went through the crack. My timeline was erased. But because I'm such a complicated person in time and space, it only managed to erase my eleventh timeline. So, I lost my eleventh body. But then, I didn't have anywhere to go, so I was pushed back into my tenth body. Just before I regenerated into my eleventh and met you. Your remembering me was only just strong enough for the eleventh me to have existed, and done those things, and for us to remember those things. But otherwise, we'll just have to wait until I die for you to see him again. Although, personally, I would rather not die just yet. But that is rather unlikely to happen at this present moment... unless..." He strode over to Rory, and grabbed his arm.

"Your not still made of plastic are you? Not about to shoot me, and everyone else?"

"No. No gun." Rory affirmed, startled.

"Good. Now," He snatched the blue diary out of Amy's hands, and casually opened it at a page, not looking at it. "Amy, does this have writing in it?"

"Yes."

"Brilliant. Now I need to return this to River. Amy, Rory, you coming?" The Doctor turned and raced back into the TARDIS.

"'Course we are! Come on Rory. See you!" Amy yelled at everyone else, and ran into the TARDIS. Rory followed, glancing apologetically at Amy's parents.

The Doctor looked up as they entered a TARDIS that was not so familiar to them.

"Right then. Allons-y!"