This is not the moon, he muses, stepping out of the TARDIS and pulling the door shut behind him. In fact, he may still be on Earth. He is standing on a gently sloping field of green grass, not far from the tree line. New England autumn, he thinks, taking in the breeze that nips at his cheeks and nose, falling just short of cold, and the brilliant reds and golds of the trees in front of him.

He walks toward the tree line. He can't help it. He knows he needs to return for Amy, but there is something in the spice of the wind that implores him to explore further. He wonders why he's never come here. As much time as he's spent on Earth, it seems silly to have missed this.

He is in the forest now. The breeze rustles in the trees and the evening sunlight filters through their leaves, falling in golden patches at his feet. He stops, turns, taking it all in. It is beautiful.

Energy crackles behind him, humming through his body and raising the hairs on his arms. He turns, and she is there.

He knew she'd scattered herself through his timeline, following the TARDIS in a desperate attempt to find him again. He knew this, but he'd never anticipated meeting her in his future.

She is staring at him, all big brown eyes, blonde hair wisping gently in the wind.

His hearts clinch. He was a fool to think that the regeneration would dull the pain of losing her. The opposite, really. Here he was, hurtling forward, unfamiliar body and all, always moving away from her. She won't even know me, he thinks, carefully keeping his expression neutral. Oh, it's hard.

She searches his face and then breaks into a smile. "Doctor."

Before he can react, she is in his arms, nestling into his shoulder. He automatically pulls her in, pressing his face into her hair, breathing in the familiar scent of her. Citrus shampoo and laundry detergent and something sweet and natural and utterly Rose. The ache of losing her will never fade, he realizes. He holds her tightly. It is beautiful and painful, healing and hurting, so different now, but still so right.

She sniffles and pulls back. He grips her shoulders. He cannot let her go, not yet.

"You aren't my Doctor," she says, gazing at him sadly, eyes swollen and wet.

Oh, that hurts. I'll always be your Doctor, he wants to say, but the words die in his throat.

She reads it in his face and pulls closer. "S'not what I meant," she says, cupping his cheek gently. She smiles at him, tongue poking between teeth, and fingers his bow-tie. "Love the bow-tie, by the way," she says as she straightens it with a gentle tug. "Very cool."

He smiles at her for the first time. How could he have doubted her, his Rose? He considers the bow-tie. He'd been second guessing it, intending to find something else when he returned to the TARDIS, but now? Never. Bow-ties are cool.

"It is, isn't it?" he says happily, tapping her nose with a finger.

Her smile falters, and she settles back into his chest. He smells almost the same, of time and tea and Doctor, but the hint of cinnamon is gone, replaced by something that reminds her of the TARDIS library. Books, she thinks, feeling the scratch of tweed against her cheek. It feels wonderful.

"I can't stay," she sighs into his shoulder.

He knows this, but he tightens his grip around her anyway. "Timey wimey," he murmers into her hair.

She pulls away. The cold wind passes between them. "No," she says sadly. "It's not just the timeline. I'm in the wrong universe."

He stills, grappling with her statement. He doesn't understand. "What do you mean? You're here, with me," he reminds her.

"But I'm not your Rose," she says, pulling at the sleeves of her leather jacket. "You aren't my Doctor. You're a parallel."

Now he is thoroughly confused. "I thought I'd explained that to you," he says, remembering the conversation they'd had on the couch in the TARDIS study. "Time Lords don't exist in alternate universes. There's only one of me."

"Yeah," she says, remembering her confusion when she'd run to the TARDIS to find herself and her first Doctor snogging in the control room, something she distinctly remembered not doing. The resulting conversation had been enlightening for all involved, to say the least. "Something about the technology being destroyed in the war," she explains feebly. She doesn't really understand it.

The Doctor's eyes widen in shock. He'd forgotten that one of the functions of the Eye of Harmony had been to keep Time Lords in one reality only. He'd never thought about the implications of its destruction on parallel universes. He wonders briefly how many other Doctors there are, and if they've all lost their Roses. He hopes not.

Rose studies him, seeing the exact moment that pieces fall into place. It's almost comical. She hopes that she'll have a chance to know this face like she knew the others, to learn new quirks and catchphrases and habits, explore a new body with new preferences. Then she remembers her Doctor, with his pinstripes and unruly hair and his (frankly amazing) oral fixation. One day, she thinks, but hopefully not too soon.

She sighs and pulls her dimension cannon out of her pocket. It is time. "Goodbye, Doctor."

He sees the familiar yellow button in her hand and pales. He isn't ready for her to go. "Rose..."

She shakes her head sadly and steps away from him. "I can't stay," she says. "Defender of the Earth an' all." She smiles at him, and his hearts break.

"But Rose," he moves forward as if to grip her hands, voice thick with desperation, eyes wide and shining. "How did you know me?"

She turns back to him and smiles shyly, but he can see his same longing echoed in her eyes. She looks at her hands. "My son,"'she says softly, running her fingers around the cuff of her sleeve. "He has your eyes."

Her gaze meets his, and something passes between them. He freezes, caught in the onslaught. It is an instant and an eternity, and when it is over, he knows. Oh, he knows.

When he comes back to himself, she is gone.