A blue police-box appears out of nowhere in the middle of a desolate street. It wheezes for a moment and the light on top flickers, before stillness and silence once more ensues. It is a box of great power and possibility – the last of it's kind – containing a person equally as remarkable and solitary in the universe.

Stepping out of the TARDIS, The Doctor quickly comes to realize that it is night-time. He has landed in a small suburb somewhere in Great Britain. A pool of light from a street-lamp encircles him as he looks around to locate himself. Houses surround the street on either side – relatively small, domestic-looking buildings, with neatly trimmed lawns and shining cars on the driveways. He walks up and down the street a few times until he finds the right house. The name on the mailbox momentarily causes one of his hearts to skip a beat.

He doesn't even stop to think before he steps onto the lawn, going around the house to the backyard. It never occurs to him that he should try the front door. His gut drives him toward the back of the house and the darkly lit garden that is located there. There, at the edge of the yard, he finds a small figure. Her back is turned on him; she is looking up at the night sky, protected only by jeans and a t-shirt against the cold October air.

He walks slowly toward her, stopping only a few feet away. The lawn is strewn with dew droplets.

"Isn't it a bit cold for just a t-shirt?" he says quietly.

She doesn't even turn around. Her eyes are fixed on the sky, face turned upwards and hands hanging at her sides. He moves closer until he is right behind her, lifting his hand to touch her shoulder, but changing his mind halfway. She doesn't seem to notice.

"Rose?" he says.

"New Earth," she says, her voice distant and thin.

"New Earth?"

He smiles uncertainly.

"There was apple-grass. He spread his coat on the ground … and we just laid there. It smelled of apples."

Her voice is frail, hardly carrying even the short distance to where he is standing. She is motionless, like a statue. It's so quiet he can practically hear his hearts pounding in his ears. Reaching out, he gently touches her arm now. It's very cold.

"You'll get sick. Come on. We should head inside."

There is a hint of concern in his voice.

Stepping around, to the other side of her, he holds her by the wrists and tries to catch her attention. Even though he's right in front of her, she seems to be looking straight through him – as though he isn't even really there. Her eyes are like the dead surface of a pond with no living organisms hidden in it. Yet, he doesn't try to urge her to notice him, or to say anything. They watch each other for a while, his eyes darting across her face as he tries to make sense of her behaviour.

Slowly she begins to tilt her head an inch to the right. Coming to life, she blinks, and her eyes, they partially illuminate with colour. Turning her palms up, she grabs his wrists just as he is holding on to hers. Her grip is quite tight – in fact, there is a force in her fingers that he has never noticed before. Then again, it's been quite a while.

He tries to smile, but is suddenly nervous.

"Are you all right?" he asks.

Her lips separate slightly, and with an exhale she breathes out the question: "John?"

He shifts his facial features as if to say: "Sorry, no," and waits for apprehension to fully strike her. For a few seconds, she just breathes. Then her head drifts another few inches to the side and she utters the first few letters of the word: "Doctor", unable to complete it once the weight of it becomes tangible.

"It's so good to see you," he says, sounding more emotional than he had intended.

Scanning him, her eyes drift from his face down to his chest, where she carefully places her right palm against it; first on the left side, then on the right. Returning back to the deep, brown of his eyes, her gaze stops there.

She asks: "What are you doing here?"

"There was an opening in the dimensional rift. I don't know how, but there was!" he says, smiling. She waits for a moment, but is offered no further explanation.

Suddenly, almost like she's falling, she ducks into his arms, pressing her ear to his chest. He gratefully wraps her close, lightly rocking her from side to side. She is smaller than he remembers; like their time apart has somehow shrunk her. Her entire body seems to heave with every breath. Her arms are snaked tightly around his waist. He knows by now that something is wrong. This wasn't at all how he pictured this moment.

"I can't believe you came for me," she mumbles into his jacket.

"Well, I couldn't pass up an opportunity to pop by now, could I?"

"Doctor?"

A third voice appearing from behind them. Letting Rose out of his arms and gently loosening her grip around him, The Doctor furrows his brow. The voice confuses him at first. But as he turns around to face its source, the pieces quickly fall into place.

"Doctor!" he, too, exclaims, as his gaze settles on an all too familiar face.

"I actually go by John these days."

Looking from one to the other, The Doctor's face is graced by a pleased expression. Rose comes up to him again, closing her small hands around his upper-arm as she leans against him. She is surprisingly silent.

"You two – still together, eh?" says The Doctor. "Isn't that lovely! How about a cuppa, then?"

They sit on the verandah underneath a warming light. The Doctor enthusiastically tells of some of his travels since last time they met, while Rose leans quietly into him. Unconsciously wrapping an arm around her to keep her warm, he notices her getting increasingly relaxed by every passing moment. She soon drifts into a half-slumber against him. After a while, he helps her inside and up the stairs to the second floor. He sits at her bedside until she falls asleep.

The house is quiet. As he descends the stairs again, The Doctor finds his doppelgänger standing at the large glass door leading out onto the verandah, facing the yard they had just been in. It is completely dark out there. In here, it seems, every corner is lit up by some form of artificial light. The contrast is striking.

Coming to a halt next to John, The Doctor, too, gazes through the window and sternly asks: "What's wrong with her?"

John glances briefly at him, but doesn't turn to face him completely.

"Nothing, really." He sounds cold and indifferent.

"You're kidding, right? Why is she like that?"

"Like what?"

"You know … sort of, just … vacant."

"That's just her, these days. She's changed since you last saw her. Most people do."

"Yeah, but it's almost as if …"

The Doctor trails off, his eyes turning glossy. He shifts his weight, shoving his hands deeply into his pockets; unaware that his stance is in every way identical to John's. He breathes deeply in, and then out. A moment of silence spreads out between them.

"She's been like that since we came here – more or less. It's this time and place, I think. This life. It's not for her. Makes her unhappy."

"I don't understand."

"No, you wouldn't, would you?"

They exchange a quick glance. The Doctor seems perplexed. A crease rests between his eyebrows.

"What exactly are your intentions with this visit?" asks John suddenly. His voice is all at once harsh, almost bitter, and incredibly weak.

"My intentions?"

"Do you intend to take her back with you?"

Surprised by the question, The Doctor turns to him. "You know I can't do that."

"Then why did you come?"

They stare at each other for a while, The Doctor scanning his duplicate's face for an explanation to this unpleasantness.

"I –," he says finally. "I guess … I wanted to see her." And adding: "I thought she would appreciate it."

John sighs and turns away from him. He collapses into himself for a second – his posture breaking down and his shoulders slouching forward, like the weight of the world rests upon them. Bringing his hand to his face, he rubs his nasal bone and then turns back, regaining some but not all of his stature.

"I don't think you quite grasp the impact that your decision had on her."

"My what?"

"Your decision to leave her in this universe. With me."

"What on earth are you talking about?"

"What do you think I'm talking about? You saw her. It's like she's had a nervous breakdown or something. Took months before she would even properly look at me. She was showing signs of getting better, you know, these last few months … but with this … " He gestures abstractly, sighing again. "We're going to have to start all over."

"Now, how can you possibly know –"

"I know because I stuck around." John exclaims sharply. "Because I've been with her all this time. I know how easily she's set off. You have no idea how careful I have to be around her, not to provoke her. I say one word wrong and she's just gone. It's this voice – this face!" He pauses. "I'm literally the single worst person you could have left her with."

The Doctor stands in awe, lips parted and eyes wide. This is all news to him – bad news, at that – and he instantly wants to reject every single word of it, but they stick to his mind like tiny pins in a cushion. Shaking his head, he searches for the right response.

"I –"

"If you don't intend to bring her with you, you need to tell her that. Don't you dare get her hopes up. Do I make myself clear?"

Hesitating, he nods and then looks away. John turns from him again and walks out onto the verandah, leaving him behind. It doesn't take long before he is devoured by the dark night.

Sitting at her bedside again, The Doctor's thoughts are doing laps inside his head. He is touching her hand, sliding his thumb back and forth across it. She is lying on her side, knees drawn up in foetal position, her hair hanging at her eyes.

"What happened to you, Rose Tyler?" he murmurs broodingly.

She doesn't rest for long. Soon, she wakes, and smiles vaguely when she finds him there. Her eyes are tired and darkly contoured, and her face has a slight anaemic tinge to it. She props herself up against the wall and holds his hand in her lap. They don't really speak, but at one point she seems to mumble the phrase: "My Doctor – you came for me," under her breath.

He wants to say something, but can't find a single appropriate word.

After some time, still holding him by the hand, she leads him downstairs and back out into the yard. They move toward a large swing hammock at one of the further ends, close to where she stood when he found her and where the darkness seems at its densest. She stops right by the hammock, then turns and looks up at the sky.

"I've been watching out for you," she says simply. "Waiting, here."

Concern clouds The Doctor's face. Turning to her, he gently utters her name, then says: "I'm not staying. And you can't come with me when I go."

It hurts even to say it, and even more so as all he can do is quietly observe when something in her eyes seem to snap, breaking her into pieces. For the longest time, she doesn't respond. She just stares, her eyes two deep, vacant slits with no light – and though it is absolutely destroying him, he cannot bring himself to look away.

Finally, she averts her gaze.

"Oh."

"I just –," he says helplessly. "I just wanted to come see you. See that you're doing all right."

She turns from him and walks slowly toward the swing hammock. Softly sinking down onto its cushions, she looks down at her hands.

"I'm sorry – I'm so sorry," he says.

"Why can't I come with you?"

"Your place is here now. With John. And your family. They need you, this world needs you."

"But I don't want them."

"Rose –"

"It's not fair."

Looking down at her, The Doctor feels his chest close and his ribs collapsing in on his hearts at the sound of her tiny voice, so filled with anger and sadness.

"We could both come with you," she adds, calmer now. "John and I. Just for a while. Just … just don't leave."

"I can't take either of you with me," he says dejectedly.

"But you could. We could come with you," Rose says again.

"We could, you know," says a voice, reluctantly, from the shadows. "It's actually not … at all a preposterous suggestion."

They are both surprised by John's sudden presence. He emerges from the dark and steps forward. Hands in pockets, he stops somewhere between them, looking from one face to another. There is something different in his expression now. A light that hadn't been there before.

"Not you too," The Doctor whimpers. "You know I can't bring you."

"Sure you can," says John.

"Please, don't do this. You of all people – you should understand this."

"I do. I understand it all perfectly."

"Then what is this all about?"

"I understand your situation, Doctor, but I also understand her situation," he nods to Rose, wide-eyed observing them from the swing hammock. "I spend every day with her and I know how much she needs this. I see it in every inch of her face; the abandonment, the disappointment. And, quite frankly … I understand it. I know how it feels."

"You, what?"

"You don't understand what it's like. Living in a different world, one that's familiar and completely alien at the same time. You don't know … what it's like to be left behind."

Grabbing him by the arm, The Doctor draws him aside, away from Rose. She watches their backs and then sinks further down into a small pile of a being, turning her eyes away from them.

"You're really not helping," The Doctor hisses.

"I'm not trying to help you. I'm trying to show you the bigger picture."

"'The bigger' –? Why do I even need to explain this to you? I can't bring you, and I can't bring her –"

"Yes, you can."

"No, I can't!" he shouts, suddenly upset. "I don't want to watch you both die. You're both human and small and fragile – you will die and it's – it's bloody easier this way!"

John's eyes are ruthless.

"For you," he clarifies. "Easier for you."

"Yes!"

"And what gives you the right to decide that what's easier for you, is the only valid alternative?" Staring at him in shock, The Doctor doesn't answer. "Why do you get to decide, and not us? Is it because you're a Time Lord and we're not?"

"Well ... yes!" John snorts and looks away, but The Doctor doesn't yield. "How do you think I've even survived this long without completely loosing my mind? With the things I've been through? Yes, it is unfair and yes, people get hurt, but I am the last of my kind and I cannot afford to be overwhelmed by humans dying all around me –"

"Then why do you keep choosing us?" comes a tiny voice from behind them. It sounds weaker now than ever before. The both swing around and she adds: "Why even choose human companions to begin with?"

Still in the swing hammock, Rose sits with her arms wrapped around her shivering knees, looking at them. They move closer to her. Her face is blank and sad.

"Why –?" The Doctor stutters.

"Why not choose someone of a different species – someone who lives longer, and isn't as fragile? You could even have an android companion – you have in the past."

John and The Doctor exchange a silent gaze. Standing there in front of her, side by side, the two of them are almost like an optical illusion. If it weren't for the difference in clothing, they would be identical.

The Doctor is silent for a long moment. Rose stares straight at him, waiting, refusing to look away. The night is getting colder and colder. Their breaths create smoke whenever they open their mouths.

"Human beings …" he starts, seemingly searching for the right words, looking exhausted. "I keep coming back to you … probably because you evoke so much in me. It's destructive, but it's the only thing that really keeps me going. The enthusiasm and childlike sense of wonder in you all … Nothing else in the in entire the universe can urge me to continue on the way you lot do. You give me something to fight for. Something to believe in. After all this time, I can still be excited by it all, because I get to experience the wonders and horrors of time and space through your eyes. So innocent."

"But it does comes at a cost," says John.

"Yes."

"Saying goodbye."

"But why now, though?" says Rose, her voice weak and pleading. "We could set a date, or something – we'll travel with you till John and I hit, say, our sixties and then you can drop us off again."

He shakes his head.

"I don't want to remember you as a sixty-year-old woman. I want to remember young, beautiful Rose Tyler. The girl who is awestruck by even the tiniest thing – whose entire face lit up when she first smelled the apple-grass of New Earth."

"But I can't stay here," she cries.

"Yes, you can. Don't you get it?" Bending down, he grabs her by the shoulders, trying to penetrate her cold eyes. "You can. No matter how deep into the well of despair you may fall, you can always – always! – find your way back up. I've seen it a million times – it's the very best thing about humans! It's what I love the most about you. I was never afraid to leave you, because I know you'll find a way, and you'll be a better person for it."

Shaking her head in response, she continues to cry. The Doctor lets his hands fall from her shoulders and stands up straight. Sighing, he looks away from them both. He stands quiet for a long while. Then he turns to John.

"She probably shouldn't be alone. Will you stay with her?"

"Where are you going?"

"I don't know."

The hammock swings soundlessly back and forth, softly cradling the bodies in it. A light hum drifts from the spot where the two of them are seated, and out into the cold night. It's a clear sky.

Rose's eyes are closed, her head leaned against John's chest as he carefully croons an ancient lullaby from a long dead planet, echoing through the centuries via his vocal chords. He's cold. The blanket wrapped around their shoulders does a bad job keeping the chilly air from reaching them. He doesn't want to disturb her and so stays where he is; arm wrapped tightly around her, shivering in the cold.

Several hours must have passed since The Doctor left.

John closes his eyes. Everything is quiet. In the first few hours of his existence, he had been directly linked The Doctor's mind, but with the time apart, the connection had slowly started to fade, until it was finally completely gone. Even just now – reunited and all – he hadn't been able to find his way back to it. The Doctor and he are separated.

In what corner of the universe is he now?

John allows his thoughts to drift away. Then suddenly, The Doctor is there. Standing before them, he doesn't really do or say anything.

"Why did you even come here in the first place?" John asks, and it's as if their previous conversation had never even ended. "What did you expect to come out of this visit?"

They are both calm, and they speak with equal dignity.

"I don't know. I just … saw an opportunity and went for it. I didn't give it much thought."

"No, well, I think that's fairly obvious." A pause, and then John's voice as hard as steel saying: "You shouldn't have come here."

"I know."

"It's not fair – the amount of power you have over her. Over us."

"Yeah."

"I think you should leave."

"I will."

But he doesn't move for a long moment. Quietly he observes the scene laid out in front of his eyes; Rose resting in John's arms and the dark surrounding them. She seems to fit perfectly into his embrace – her face resting on his chest, her hand since long fallen into his lap.

Why can't it just be as simple as this? An embrace. Peaceful rest.

It could have been perfect. It should have been perfect. For the life of him, he couldn't understand where he had gone wrong. The only thing he ever wanted was for her to be happy. John, too – though probably for more abstract, existential reasons.

He steps closer, ducking down to place a kiss on the side of her forehead, careful not to wake her. His lips hover for a moment at her skin, as the scent from her hair strikes him. His throat turns into a tight knot, but he manages to pull away. He steps back. Rose continues her rest undisturbed.

"Take care of her, will you?" he says to John, his voice partly breaking.

"Like I'm going to stop now."

Turning his back on them is the single hardest thing he has ever done, but he does it nevertheless. As he disappears into the dark, the image of Rose and John lingers in his mind. It is both comforting and an incredible torture. The TARDIS seems emptier than ever before and he takes off, knowing not where to go. In the entire universe, there isn't a single place he wants to be right now.

He wishes, for a moment, that he could simply disappear, sliding out of time.