A/N: Thanks to everyone who has reviewed/favorite/followed my story! For those in the last two categories, don't hesitate to review as well! I forgot to mention, the title of this story is from the song Of Nature, by Faunts.

The Doctor drops down on his armchair in the console room and closes his eyes, trying to shake the day away. The adventure on Reznak II has been particularly exhausting, thanks to a mad scientist and his delusions of grandeur. He sighs, rubbing his temple with one hand as he recalls the insane glint in the man's eyes as the Doctor had him trapped on the roof of his lab, preferring to fall to his death rather than being handed over to the authorities. He tries to push the guilt and pain away as he takes a sip of his tea. If only living beings would stop seeking power and domination over others… But that will never happen. As long as there is life, there will be evil.

He needs a vacation. Somewhere uneventful, peaceful and quiet, where he could just take in the sights. But then, trouble always does seem to follow him anywhere he goes. Usually he doesn't mind. Most times he actively looks for it, but right now he just wishes it could all… stop.

As if on cue, the TARDIS starts to shake violently, throwing him out of his armchair and spilling his tea on the floor.

"What's the matter, old girl?" he asks in alarm as he feels her cry out, clearly in pain. The shaking only intensifies in answer, and he rushes to the console as fast as he can.

He has no idea what is going on. They are supposed to be drifting safely in the Vortex, but he can quite clearly see that they are in flight. He circles the console in alarm, pulling levers and pressing buttons to try and stabilize her even as the shaking continues and circuits start to smoke.

They land with a crash that knocks him off his feet. He rushes back to the console, trying to figure out what happened, where they are, but the monitor is only showing gibberish and most controls seem unresponsive.

"Are you alright?" he asks his ship, worried. He can feel her, weak and in pain, and the floor is still slightly shaking even though they are no longer in flight. The doors open suddenly and he feels a feeble nudge against his mind. She wants him to leave so she can repair herself in peace, he knows.

"Are you sure? I could help."

He senses her pushing him out, almost desperately, and he tries to swallow back his concern for his beloved ship as he moves towards the door. Best to go out and explore, then. Picking up his overcoat on the way out, he puts it on over his vest before stepping outside and carefully closing the doors behind him.

He stops just outside the TARDIS and closes his eyes, his senses assaulted by a peculiar sensation. There's a sort of strangeness in the air that he can't quite define, as if the very fabric of time and space is just slightly off. He couldn't exactly say how it's wrong, and it's not overwhelming, either, just… unsettling.

Shaking off the feeling, he looks around. He seems to have landed in an abandoned building of some sort. He is in a large room with pieces of broken equipment strewn everywhere. And… what appears to be a large empty cage alongside one of the walls. Curious. Not the sort of thing you'd expect to find in your standard old building.

There are two doors leading out of the room and he hesitates for a moment, unsure where to go. Before he can decide, however, he feels a small tingle on the edge of his senses, just for a second before it disappears. He has no idea what it was, or if he has ever felt anything quite like it. It was clearly originating from the corridor on his right, however, so he quickly moves in that direction.

Whatever caused that strange feeling is rather shy to make itself know, he thinks wryly, as he makes his way down a dark and dusty corridor, broken down doors leading to more empty rooms on either side. He starts questioning if he imagined the sensation when he turns a corner and abruptly comes upon a body, a woman bundled awkwardly on the floor against the wall.

He's at her side in a second, crouched next to her. Her posture is unnatural; something has certainly knocked her out (or worse, he tries not to think). He gently pushes the strands of the honey blond hair obscuring her neck as he reaches to feel her pulse, praying to gods he doesn't believe in. She looks so young…

He releases a breath he didn't realize he was holding as he feels a weak fluttering in her neck. Faint, so faint… but it's there. He's reaching for his sonic, hoping to figure out what's wrong with her and stabilize her before it's too late, when his fingers at her neck brush against metal, and a glint at her chest catches his attention.

He takes a sharp inhale of breath as he sees the small key dangling from a simple silver chain, half hidden by the neck of the woman's black t-shirt. Even though it's not the same kind of key he's using right now, there's no mistaking the unique energy signature emanating from it. This is a TARDIS key.

Hs eyes flash back to her face, widened in surprise. He hadn't taken the time to really look at her as he rushed to her side before, anxious as he was, but he studies her now. Honey blond hair, which he'd noticed before, darker roots faintly showing. Plump, full lips, round cheeks, smooth skin. Pink and yellow. The thought comes to him, unbidden. He shakes his head slightly. She's lovely, really lovely, but… he doesn't know her. He would certainly remember giving her a key to his home, in this incarnation or in previous ones. Which only leaves…

Of course. A future him. This must be why he's here. The only reason he could cross his timeline in such a way. The Time Lords must have sent him to help a future version of himself.

Although… why didn't they bother to tell him that? It would have made things rather clearer. He supposes the problem with the TARDIS impacted the Time Lords' ability to communicate with him. He can only hope that things will go better from this point on, albeit he's not optimistic about this. He has no idea where or when he is in his own personal future, or why he is here, his other self frustratingly absent, and his future companion all but stricken down…

This thought makes him start, his attention focusing back on the woman before him. Her pulse is still so weak that he is scared it will disappear entirely, and his hand is moving towards his pocket again, where his sonic screwdriver is, when a loud, rumbling noise interrupts him.

Is that he sound of… engines? Yes, definitely, a spaceship, not far from here. What sort of engines are they? He strains his ears, trying to pick up the subtle unique patterns such technology always exhibits, when it is suddenly covered by the unmistakable sound of gunfire.

He starts, shakes his head. Right. Unidentified aliens with spaceship technology, gunfire of unknown origin, potentially dangerous situation, injured companion. Not exactly the time and place to shilly-shally, nor to try and solve mysteries by himself. He carefully gathers the unconscious young woman in his arms and strides backs to the TARDIS.

It is only when he comes in sight of his ship that he realizes she might not be ready for him yet. She had seemed badly hurt when they landed, although he has no idea what could have caused it. He had been hoping to get the woman in his arms to the infirmary before attempting to locate his future self, but the thought that he might not even be able to enter his ship makes him stop short.

His misgivings are answered when the doors to the TARDIS open widely on their own, as if she sensed his arrival and wants him to get in as quickly as possible. He wastes no time obeying her. He strides quickly inside, kicks the doors closed behind him and is about to take off towards the infirmary when he notices that the corridor leading away from the console room to the rest of the ship has disappeared.

"She's hurt," he addresses his ship. "I need the infirmary. Can't you manage that at least?"

He only gets a whimper of pain in reply, from his ship as well as the woman in his arms.

"Alright, alright," he mumbles, crossing the room to deposit the woman in his armchair. He turns back and marches to the console "A hospital then. I could at least get some equipment there, find out what's wrong. Now let's try and figure out where and when we are…"

His back is to the woman in the armchair, so he misses the golden glow that spreads over her body and engulfs her for a moment before fading. He is so concentrated on trying to make sense of the gibberish on the monitor that he doesn't take note of the swell of energy in the console room. It is only when the writings on the monitor finally snap back to Gallifreyan that he looks up at the time rotor, beaming.

"Ah, perfect! Feeling better, old girl?" The TARDIS sends him an uncertain thrum which makes him frown in worry. A beeping sound from the monitor snaps his eyes back to it. "London, twenty-first century. Hmm… Not too bad, could be better. Let's see, hospitals in London, familiar with alien technology… UNIT? They have a medical facility… Yes, that will have to do. Do you think you could manage a small jump in space?"

At the weak affirmative hum, he jumps into action, inputting coordinates and preparing them for flight. The TARDIS takes off amidst strained sounds and muted shakings, but manages to land shortly after. The Doctor strokes the console fondly for a moment, thanking her for the effort, before turning to the still unconscious woman slumped in his armchair. She has gained some colors back, he notices with satisfaction, and when he checks her pulse he finds it stronger than before. This is all very encouraging, but what he really wants is to get her under a scanner and find out what is wrong with her. He takes her in his arms gently, careful not to jostle her too much, and exits the TARDIS.

He almost drops her in surprise when he sees where they are.

"What…?"

The TARDIS has landed in the corner of a living room. In front of him is a comfortable-looking dark blue couch facing a television, a small coffee table in between. Further ahead he can see what is presumably the front door, framed with a few hanging coats and pairs of shoes. To the left, a hallway leads away from the living room. The whole area is bathed in fading afternoon light from the windows behind him.

He's landed in a flat.

His first thought, after the initial surprise, is to think how rude this is, landing in someone's home. His second, more rational, is to wonder how he got here. Wrong coordinates maybe? Or something still affecting the navigational system of the TARDIS?

The place is quiet and still, and it seems empty, which he is thankful for. His eyes roam over the place as he mulls over what to do next. Should he try to take off in the TARDIS again, risking another error like this? Or stay here, wherever this is, and try to get some help? He takes a few steps towards the couch, meaning to set the woman in his arms down on top of it to better consider his options. As he does so, his eyes fall on the small side table next to it. On it are a reading lamp, a book, and… a picture. A picture of the woman in his arms, smiling at the camera alongside an older blonde woman with a baby in her arms.

Oh.

It's her flat.

And now he's more confused than ever, because this can't possibly have been an accident. This means that the TARDIS wanted to bring them here, although why she did so is completely beyond him.

He takes in the area once again, looking at it with a new eye. With the exception of the picture on the side table, the room is very sparsely decorated. Everything in it is tidy and clean. It doesn't look much lived-in, and the room emanates a rather impersonal air. This surprises him. It's true that he doesn't know the woman in his arms, or not yet anyway, but he has the inexplicable feeling that this shouldn't be where she lives, that this is wrong.

He thinks… that she is the type of person whose personality should shine and touch everything around her.

Shaking himself from his thoughts, he sets the woman down on the couch. Surely, if the TARDIS brought them here on purpose instead of in a medical facility, she must be out of immediate danger. Still, he kneels on the floor in front of her and takes out his sonic screwdriver. She looks much better. Her pulse is now strong, her breathing normal. She simply seems asleep. One more thing to puzzle over. What happened to her that she seemed close to dying when he found her, mere minutes ago, but had now almost completely healed from, without any medical attention?

Trying to crack this mystery, he scans her with the sonic. When he can't find anything conclusive, he changes the settings and scans her again. And again. He can feel some strange energy around her, made stranger by the fact that it seems almost familiar, although he can't quite figure out why. But he can't find anything with the limited resources he has, and he reluctantly gives up trying. He pauses, looking around once more.

Well. Since this is her flat, he might as well put her in her bed and let her rest comfortably. He takes her in his arms again and heads towards the hallway leading to the rest of the flat. He passes the kitchen and the bathroom, peeks inside a room to discover it is a workspace, a desk with a computer and scattered papers flanked by well-filled bookcases. He finally finds the bedroom as he reaches the furthest door of the hallway. In the center of the room thrones a large plush bed with a soft pink comforter. Another bookcase stands next to an armchair on one side of the bed. On the other side is a wardrobe. He sets the woman down on the bed and straightens up, hesitating as he contemplates the wardrobe. Maybe he should change her into pajamas: it would be more comfortable for her than the clothes she has on. The thought of undressing her, however, unnerves him. He frowns, trying to get rid of the sensation. He shouldn't feel this way. Yes, she is a lovely young woman, but he is above such things, above baser feelings like lust or sexual attraction. Nonetheless, the nervousness persists and, shaking his head, he decides against it, settling on simply removing her shoes and her jacket.

Once this is done he leaves the room, makes his way down the corridor and turns into the living room, intent on checking on the TARDIS. The sight from the windows freezes him in his steps. He had his back turned to them before, so he hadn't noticed it, but it's hard to miss now.

This is London, no doubt about it, except the London he remembers doesn't have quite so many zeppelins it its sky.

"What in the world…?" He closes his eyes for a second, exasperated by the strangeness of the situation. This whole adventure has been one perplexing surprise after another, and he wishes he could just understand…

The realization comes in a flash.

Parallel universe. Of course. This explains the strangeness in the air he's felt ever since he landed.

One mystery down, at least. Or, well…Really, this just adds more questions, doesn't it?

He sighs, turning away from the windows towards his ship. Time to locate his future self – he must be here somewhere, even if for some reason he can't sense him right now – and figure out what exactly is going on here.

An hour, thirteen minutes and twenty-six seconds later, the Doctor feels like banging his head on the console. He has gotten absolutely nowhere in his search for answers. He can't locate his future self, he can't communicate with the Time Lords, he can't even properly figure out where he is. He is beginning to doubt his previous assumption of being sent here to help a future incarnation. If this were the case, wouldn't he have received some form of communication by now? And he really should be able to trace his future self in some way, but it's as if he's completely disappeared from this universe. But then, how to explain landing next to a future companion still carrying a TARDIS key? It would certainly be too much of a coincidence to be believable.

What's more, the TARDIS is being strangely uncooperative, and he suspects she has a hand in all of this. She seems to have recovered from whatever happened to her earlier, but she writes gibberish on the monitor, she is silent to his requests to open more rooms. And she refuses to leave, whether it is to go back to the warehouse or to UNIT, even if he promises it would only be a quick trip there and back to gather some information.

He considers leaving by the front door - nothing she could do to stop him, then - but hesitates to leave the unconscious woman alone. Without the TARDIS, he can't leave and be back a second later, and he doesn't want to risk her condition deteriorating without him being there. He can still remember how faint her pulse was, how close to death she looked. He doesn't trust her sudden and unexplained recovery, and he doesn't want to risk anything happening to her. In the end, he walks back to her bedroom, scours her bookcase for an interesting title – Dickens, how delightful - and settles in the chair next to her bed with a sigh.

Fine. The TARDIS wins. He'll stay here like a good boy and wait for the mysterious companion to wake up.