Rose was stuck. She got up every day with her alarm, pulled on a version of the same jeans and hoodie outfit she wore every day, and took the bus into town… just like every other work day. Lunch with Mickey in Trafalgar Square, just like they always did when he could get away, then back to work.

Lunch was the hardest part, really. Well, any time spent with Mickey. After dating for three months, they both knew they weren't soulmates. Rose suspected Mickey harboured feelings for her and would be happy to dismiss the idea that there might be someone else out there for him, but she just… couldn't.

She wanted that rush, the moment when she took her soulmate's hand and could see all the lives he'd lived before. She wanted to share the life he was living now.

But she had to find him first.

Four hours later, Rose cowered against the basement wall as an army of shop window dummies advanced on her, cursing herself for moaning about her boring life. Boring was still alive, at least.

Then a hand took hers, and her head snapped around to find the person it belonged to. Brilliant blue eyes sparkled at her, and he said just one word: "Run!"

At least, she thought that was what he said. It was hard to focus on the here and now when her mind was being flooded with images of people and places she'd never seen before. A man with a Beatles hair cut, a tall bloke with a ridiculously long scarf, a blond in cricket garb…

The second time she met the Doctor, the day after he blew up her job, she saw strange places she could never imagine. Red grass and orange skies and the light from two suns shimmering off silver trees. She looked through the door of a blue police box and saw an enormous room, much bigger than the outside of the box.

And then she watched him step into that same bigger-on-the-inside box, and she knew she needed answers. Who was her soulmate? What was he?

When she visited Clive that afternoon, she didn't blink at his stories about the things the Doctor had done. Just two days ago, she would have dismissed him as a nutter with some conspiracy theory, but after everything else she'd seen of her soulmate's life, the idea that he was some kind of angel of death, showing up at every tragedy in human history, was frankly a better theory than anything she'd come up with.

She stared at the picture of the Doctor on Krakatoa, then asked the question in her mind. "You said it's a title passed down from father to son," she said. "Has the Doctor always looked like this, or… I mean, surely not, right?"

Clive blinked up at her, then a broad smile stretched across his face. Obviously, no one else had ever taken him quite so seriously when he started rambling about the Doctor.

He fumbled through his portfolio and finally pulled out another picture. Rose immediately recognised the blond in cricket whites, and she reached for the photo without realising it.

"Who do you think he is?" she asked, studying the younger face of her soulmate's past incarnation.

Clive took a deep breath. "I think he's the same man. I think he's immortal. I think he's an alien from another world."

In her mind's eye, Rose pictured that red grass and orange sky. An alien from another world.

She blinked once, and realised Clive was looking strangely at her. "Right!" she said, a little too brightly. "Well, thanks for your help. I should go now—after all, my boyfriend is still waiting to make sure you aren't gonna murder me."

Twelve hours later, the Doctor—her soulmate—stood in the doorway of his spaceship, inviting her to come with him. Rose took a step forward, but Mickey's arms around her legs stopped her.

"Don't. He's an alien. He's a thing."

Rose sighed and looked at the Doctor. "Gimme just a minute to say goodbye, yeah?" An emotion she instinctively recognised as surprise lit his blue eyes, and she realised he hadn't actually expected her to come with him. There was something there, some feeling of unworthiness that they'd need to work through, but that could wait.

For now, she looked down at Mickey. "Micks, look," she said, keeping her voice low and hoping the Doctor didn't have like, super-hearing or something. "You and me, we were never gonna work long-term. You know that."

"Is this about that soulmate rubbish?" Mickey said fiercely, rocking back so he was sitting on his heels. "You know I don't care about that, babe. I just want to be with you and make you happy."

Rose pinched the bridge of her nose. "Yeah, well I do care about it," she snapped, before taking a deep breath. "Especially since I finally found 'im." Mickey's brows drew together in a deep frown, and she rolled her eyes. "The Doctor, you idiot," she hissed. "He's my soulmate."

Mickey tumbled back on his arse in surprise, and Rose took advantage of the moment to step away from him and jog towards the TARDIS. She looked back when she got to the door. "I'll see you later."

The Doctor was already standing by the centre console, and Rose watched him as she closed the door and walked down the ramp. He kept fiddling with controls instead of looking at her, and the tips of his ears were bright red.

Oh, bugger.

She took a deep breath. "So, you won't look at me, and I'm guessing that means you actually do have super-hearing."

The flush went down his neck, but he looked up at her. "Something like that," he admitted. "Soulmates, Rose Tyler?"

She bit her lip and studied him. If he was an alien, maybe they did soulmates differently. But all she could do was tell him what she knew. "You used to wear this really long scarf."

His eyes widened, and she took a step towards him.

"And then in one life, you had a yellow car you named Bessie."

The Doctor leaned forward on the console, like his knees had just given out.

"And whoever told you that celery was an accessory?"

He laughed breathlessly. "I heard humans could see past lives when they met their soulmates."

Rose tilted her head and looked at him. "What do you see?"

The Doctor swallowed hard. "I can see… past timelines. It's hard to explain. But I haven't been looking at timelines at all lately, so I haven't…" He held out his hand. "May I, Rose?"

Rose's heart raced when she took his hand. The Doctor immediately sucked in a deep breath, then his eyes slammed shut. In addition to feeling the turn of the Earth, Rose could see the hazy memory of recent loss, and she knew without asking that whatever had happened, it was why he hadn't expected her to come with him.

The Doctor rocked back on his heels and his eyes opened. "Rose," he breathed, his eyes wide with awe. "You are… in the very fabric of time itself. And your life is bound to mine, forever."

Rose squeezed his hand. "Well, it better be."

The Doctor shook his head slightly, and Rose got the impression that there was more to the word "forever" than how it sounded to her. But then a wide smile stretched across his face, and suddenly her heart was racing so fast she couldn't think about anything except the man in front of her.

He let go of her hand and turned back to the console. "Where would you like to go first, Rose?"

She grinned at him, smirking to herself when his gaze zeroed in on the tip of her tongue that she let peek out between her teeth. "I don't know—why don't you impress me?"

The Doctor's eyes narrowed at the challenge. "All right then, Rose Tyler." He reached for the TARDIS controls, a light shining in his eyes. "Have I mentioned, it also travels in time?"