it ends with a teardrop.

She is standing in a brilliantly-lit room. Her eyes find the contours and curves of her old console room. Her gun is in her hands, not held up as it was before (alert, she is always alert) but lowered, swinging against her hips (she is not alert now).

She had planned on storming in, guns blazing, a team of trained men just behind her, all with the stiff determination in their eyes that comes with six years of fitness regimes, alien tech analysis, and that deep-rooted suspicion that comes with being around the Academy for too long. Unfortunately, not all had gone to plan and now she is stuck in this room that looks so familiar but so alien.

That's where mum sat when we left home for Torchwood, she remembers. She feels nothing, not a pang of guilt or a wretched feeling of despair. It has all been washed away since she last stood on the beach of Darlig Ulv Stranden. Memories mean nothing to her now, she has faced her demons, been through hell and back. She is a soldier, a commander. A fighter.

He stands at the top of the stairs, leaning over the railing, staring down at her. He should speak to her. Let her know he is here. But he can't. He never could. It's Rose, for crying out loud. She is standing there in all her brilliant audacity and her eyes are taking everything in and she looks so vulnerable. He wants to speak to her. He knows it will not matter to her that he has changed. He knows it will not matter to him that she has changed.

No, he can't do it. He will just have to tiptoe away, back down the labyrinthine corridors of the TARDIS and find Amy and Rory and tell them about something unimportant. And as he turns away from her, she looks up.

"Hello."

A statement, a nod of confirmation, of approval. She knows who he is. He can do nothing else but to turn back and smile, his arms bent awkwardly at the elbows. He is painfully aware of their position in the air, hands level with his shoulders. Quickly he drops them to his sides.

"Hello."

His reply is not as confident as hers. His voice shakes. Why does it shake?

"Are you...?"

He nods. "Yes."

She regards him with a look of wonder. His tweed jacket, his braces, his shirt, his bowtie, his bowtie. He has a bowtie. Gone are the pinstriped suits, the long brown coats, the trainers. Even the leather jacket, and the jumper he had in every colour of the spectrum that she teased him about mercilessly.

She has not let herself look at his face yet. She watches as he makes his way down the stairs, taking each with a small bounce in his step, as if not yet fully accustomed to the way his feet move. Where is the schoolboy energy, the determined excitement to show her the universe?

When he does arrive at the bottom of the stairs, he jumps off in a way that makes her smile. To avoid immediately facing her, he runs his hand over the TARDIS console as she watches. Remembering. Learning.

"Doctor."

He spins, faces her, smiles, looks at his shoes.

"Doctor, you've... changed."

"You have, too."

"I know."

She purses her lips, afraid to look at him completely and destroy this illusion she must be having. He breaks the silence that has fallen.

"Your hair's longer."

"So's yours."

A small smile graces his face then. And she can see the man she travelled with in that smile. So she smiles back and his grin widens and she's laughing and he chuckles this chuckle that she thinks she could listen to all day.

But she doesn't have all day. A quick jerk back to reality, she glances at her watch. It isn't really a watch, but that doesn't matter.

"Doctor, I shouldn't be here. I've got to go."

He nods in understanding. "Before you go, though... Rose," (she smiles because her name from that voice sounds new), "Tell me about yourself."

They could be strangers, meeting in a bar on that planet they once visited, exchanging life stories, knowing that they will never see each other again.

"I'm..." What does she tell? "I've left Torchwood."

He raises his eyebrows, and then makes a face where his left eye squints as if he is trying to see things differently. "And that's okay?"

"Yeah," she smiles a wide smile. "Yeah, that's great 'cause now I'm working at the Academy – it's like UNIT, but not as discreet. Torchwood merged with it a while back. You do six years of training and at the end of it they give you a gun and put you in some poor sod's regiment."

"You're – what are you?"

"Captain Tyler. I completed training years ago."

"How many years?"

"Two. It's been eight years since you left me."

She doesn't mean the words to come out so harshly, but he doesn't seem to notice. Instead he says,

"It's been three for me. Three years, I mean."

She nods, not entirely understanding what is happening.

"And what about me? What am I?"

She cannot picture this man in front of her as the Doctor she has at home. She answers anyway.

"You're travelling. The world. You said you don't want to keep fighting for another lifetime. So you're travelling."

"And you and me, we're still...?"

She nods in confirmation. That is all he needs.

"Right." And he tweaks his bowtie.

"Doctor?"

"Yes?"

"Can I ask you a question? What is that?"

"What, this? It's a bowtie. My bowtie."

"I know, but why do you wear it?"

"It's cool."

She laughs outright at that. He looks vaguely annoyed.

"Look, did you come here just to laugh at my bowtie or did you have a real reason?"

She stops laughing to reply.

"Um, actually, I'm stuck."

He takes this in. "Right."

"What about you?" She asks suddenly. "How did... this happen?" She is gesturing at his jacket, at his hair.

"An accident. I was helping someone. A friend. Donna's grandfather."

It is the first time he has spoken of Donna since he last saw her.

"Ah," Rose nods. "And now? Have you got anyone?"

"Yes. Amy. Amelia Pond. Oh, Rose you'd love her. She's brilliant. And Rory. They're married. Can't stand married couples." He gives a shudder he knows she knows is more for effect than anything.

"I'm glad. You're happy, I mean. I'm glad you're happy."

The corners of his mouth tweak up. "Good." And suddenly he is back to being the Doctor.

"Now, you said you're stuck? How did you get here, Rose Tyler?"

She shakes herself out of this reverie, this dream in which she has met the Doctor and nothing is wrong.

"I – Accident. We were investigating a – well, it isn't important but I got sucked through and landed here. Nice TARDIS, by the way," she hurriedly adds.

"Thank you. Sexy, isn't it?"

"You still stroke bits of the TARDIS, don't you?" She recalls Sarah-Jane's words.

"Yeeess, oh! I saw Sarah again, she's doing marvellously!" He has noticed the reference to times gone past.

"That's great."

If he notices she does not sound as heartfelt as before, he doesn't show it. Instead he turns around and fiddles with the console monitor. Then he says,

"What's wrong?"

"Nothing, nothing. It's just... Sarah-Jane died. In the parallel world. In my world." She has no reason to conceal information from him. It does not concern him, yet she knows it will.

His face falls. "Oh."

And that is that. There are no more words to share between them. They have said all they wanted to say, and now Rose knows it is time to go. Perhaps that last blow was too much for him. It is not his Sarah-Jane, his Sarah is alive and well and happy. But it happened to Rose's Sarah-Jane. So it hurts him.

"Goodbye, Rose."

He pulls a lever, takes out his sonic screwdriver from his jacket pocket, points it at her, watches as she fades away in a haze of colour (TARDIS blue and a yellow that is reminiscent of her hair, he imagines) and is gone. This time, forever. No more chance meetings.

She hadn't said goodbye. She will see him, he knows, when she returns home and her Doctor is waiting for her. He will have to carry on, letting the hurt in his heart heal a little more every time Amy smiles at him, or Rory asks after him.

He will be fine. He has his friends, the universe, adventure, excitement, he has everything. Not Rose, but everything else. She is happy. It is fine.

He climbs the stairs, his steps heavy and aching with the rhythm of loss. It is not fine.