This story starts on an innocuous spring day, in the year 2000, in London, England. The Doctor was just... floating through space, his companion Amy Pond in the next room when suddenly, the TARDIS fired up without his permission.

"Hey, hey, where are you going?" The Doctor demanded, lunging for the console. "Powell Estates, London, 2000? You miss her too. I know. But—" The TARDIS didn't respond to his arguments, landing smoothly on the sidewalk. Amy had come out when she heard the TARDIS activate, and immediately dashed off to do some shopping, happy to be somewhere resembling modern earth.

Rose Tyler was fourteen years old and walking home from school when she nearly walked into a bright blue box that was parked on the sidewalk. A man came around the front—a goofy-looking, brown haired man with an old fashioned jacket and a bowtie.

Rose backed away. Her mother was always telling her not to talk to strangers, and this man seemed stranger than most.

"Rose?" he asked incredulously. "Rose Tyler?"

"Who are you?" she demanded. "How do you know my name?"

"That's a loaded question, Rose. I just—you look younger. How old are you?"

"Fourteen," she blurted out. "Who are you? How do you know my name?"

"Rose Tyler. I am the Doctor," he answered, vaguely pompously, but also a little bored. As if he was used to giving the introduction, and felt that he should be proud of it, but it had gotten old after about five years from getting his Doctorate.

"Doctor who?" she asked, more of a prompt than a question.

"Just the Doctor," he said cheerily. "Rose..." his voice sounded broken, as if he had been hurt a great deal. "Rose, I really shouldn't, but I can't help myself."

"Shouldn't what?"

"Change history. Change the future. Change my future. Change everything. But... as long as I'm careful, it won't create a paradox."

"A paradox?" Rose asked. "How could you create a paradox?" She had just learned about paradoxes the other day, in fact. It was something that she was proud to have learned—school wasn't usually her thing. "A paradox is something that doesn't make sense—two factors in one loop that contradict each other. 'I am lying' is a paradox, because if I am lying, I'm telling the truth because the statement is correct, and if I'm telling the truth then the statement is false, making it a lie, which makes the statement true, which of course, contradicts the statement again."

"Yes, exactly." He looked thrilled. "And a time paradox is when something within time doesn't make sense. If I go back in time and kill my father before he meets my mother, then I would never have been born. But because I was never born, I didn't go back in time to prevent my own birth, therefore I would have been born as I was supposed to. But because nothing's changed, nothing will stop me from going back in time and preventing my birth in the first place. You see? It's a closed loop that keeps on repeating itself and can't escape. But if I'm careful... If I'm careful, I can succeed. I can't lose you again, Rose. So I'm going to make sure that I've never lost you in the first place."

"What are you talking about? Did you escape from the loony bin?" She backed away some more. "Why do you sound like you know me?"

"Rose... How about I tell you a story." He raised his hands in front of him and tried to look non-threatening. "Yeah, that's perfect! I'll tell you the whole story and then wash my hands of it! I can leave it up to you, and you can change the future! Except that I can't stay away, or the future—I'll just—Amy! Where's Amy?"

He scanned the street behind him. "Oh, right, she went to the village for... nevermind that, now. Rose Tyler, would you like to see all of time and space?"

"I don't know who you are, but you're scaring me," Rose said.

"Look, just step inside the box—if I'm telling the truth about our story, which you'll see in a bit, then it'll prove it. And if not, it'll just be a box. Look, I'll just back away—you go inside, and then come back out and tell me if I'm crazy."

"You are crazy!" Rose said. "I don't know what you think your box is, or why you think that I would go inside of it, but—"

"It's my space ship. And," he added, smirking. "Did I mention that it also travels in time? Saved my entire world once upon a time, those words. Come on, then. Go inside!"

He had backed straight into the street, far enough away that she thought that he couldn't trap her in the box. She figured it wouldn't hurt to take a peek, just be totally sure that he was insane. Watching to make sure that he didn't move closer to her, she cautiously crept forward to the open door of the box, propped it even further and peered inside.

It was massive. There was a flight of stairs along the far wall, leading up to a platform with a large centre thing on it. The floor and sides were riddled with massive holes.

Rose pulled her head out the door and looked back at the Doctor. "It's bigger on the inside!" she blurted out, astonished.

"It looks a bit different from the way it will when you see it for the first time, but yes, it is. That's the first thing you said before, too. Now, will you step inside and let me tell you a story?"

"Just because you're telling the truth about your spaceship doesn't mean that you aren't going to hurt me," Rose said primly.

The Doctor winced. "Got to love Jackie Tyler, don't I? Taught you well and good how to be careful."

"You know what else she taught me? How to kick creepy people in the balls," Rose shot back. "How do you know my Mum?"

He grimaced. "She slapped me. Several times. And, on a couple of particularly memorable and unpleasant occasions, kissed me. Sort of miss her now, though. Anyway, I don't mean you any harm. Please trust me, Rose. I would never hurt you. I might inadvertently ruin your life by refusing to stay away from you when it is clearly better for you if I do, but I would never hurt you. And if I was a better man, all I would tell you right now is that when a guy in a leather jacket saves the world from some mannequins and asks you if you want to see the universe, you should say no. But I'm not, so I won't. Please, Rose, please believe me."

Rose looked at him. He looked so sincere... and she would like to know how the box was bigger on the inside then the outside.

"Well, all right," Rose said. "But I have to be back before my Mum gets home at five-thirty."

He grinned at her, heartbreakingly happy, almost earnest. "Thank you, Rose. You won't regret it. Or, you might, but I really hope that you don't."

"Now, I'm going to tell you the entirely true story of a man called the Doctor, and his adventures in a blue police box, with the woman that he loved named Rose."

"Me?"

"Yes. You. Or, the person that you'll become, at any rate. We don't meet for the first time until you're nineteen. It was two incarnations ago, but I remember as if it were yesterday."

"Incarnations?"

"The first thing that I have to tell you is that I'm a Time Lord. Not human, an alien. And instead of dying, we regenerate—change every cell in our bodies, become different, inside and out. I didn't tell you that the first time around, and that led to a bit of trouble when I regenerated in front of you, but now I plan to tell the truth up front. And I first met you two bodies ago. I had big ears, really short hair and a beat up leather bad boy getup. And a Northern accent—lot of planets have a north, before you ask."

"Okay..." Rose said. "So, if I'm going to meet you in five years, having become the woman that you love, why are you telling me all of this now?"

"Because I lost you, Rose," he said, looking haunted. "I lost you, and I can't stand that. And now, I'm going to tell you exactly how it happened, so that we can prevent it. You've never met this version of me—you knew my last incarnation rather well, but I lost you before I regenerated last time—produced a clone that I hope that you're happily married to, or else I'll have to kill him. But I'm fundamentally selfish, so I can't just leave it be. Not now that I'm here. Come inside, Rose, and I'll tell you everything."

Rose was captivated by this haunted man that said that he loved her—she hadn't quite outgrown the internal longing for a handsome prince to take her away on an adventure, and here was a man who was claiming that it would happen five years from now, and that he would be the person it would happen with.

She stepped inside the TARDIS. The middle console let off a bunch of flashing lights and happy beeps. "The old girl approves," the Doctor said, placing a hand on her arm and guiding her through. "Good to know.

"This story rightfully starts much earlier than this, but for the sake of time and both of our sanity, I will begin it when we first met. You were working at a department store in London—don't rightfully know its name, frankly, I didn't care. All I cared about was stopping the living plastic," he began, leading her through the main room and to a futuristic looking kitchenette. He gestured for her to take a seat on a barstool, and sat on the table with easy grace.