A/N: Yep, you guessed it, your obligatory Human Nature AU with Rose. Except, this time, I've changed it a little more. This one is set during Series 4 rather than Series 3 and thus Donna is the main companion. For her, it fits some time after the Doctor's Daughter since she already knows Martha. Rather than setting it in 1913, I have set it in Donna's time - so 2009 (thereabouts).

I don't know how long this will be, nor how regular updates will be, but I guess we'll see.

Hope you enjoy this and think it's worth continuing. Let me know what you think! :)

Donna awoke to the sound of her phone ringing loudly by her ear. She groaned and rolled over, getting ready to tell whoever was on the other end of the line to shut up and let her sleep.

She picked up the phone and pulled out its charger, squinting as the bright light from the screen hit her eyes. She was not awake enough for this. Whoever was calling had better have something important to say.

When her eyes had adjusted to the sudden light, she groaned in annoyance as she read the name John under caller ID. What could he possibly want at – she checked the time – seven in the morning.

Pressing the call button, Donna sat up and put the phone to her ear.

"What?" She asked.

" Donna, hey! What time were you coming 'round today to pick up that new telescope part I found for your grandad? I thought we could also grab a bite to eat as well since you're coming down. I was also thinking of inviting Martha," John Smith said down the line. He was far too awake for Donna's liking. But that was just him: a complete tireless bundle of constant energy. He never seemed to sleep. In that respect, he was just like his former Time Lord self. Although, he had learnt – very early on, it should be said – not to wake her in the mornings, not matter how much he wanted to take her to 'planet plog'.

John, on the other hand, hadn't yet reached that stage and, with only two months before he was due to change back, Donna suspected it was just something she was going to have to deal with.

"I'll be round about eleven-ish. And yes, lunch sounds good, so long as you're not cooking and we don't go to that chippy down by that estate again. I'll give Martha a call once I'm up."

"Brilliant! I'll see you in a few hours then. Sorry for waking you," he hung up and Donna shook her head before making her way out of bed. As much as she was enjoying being back on Earth without and bug-eyed monsters chasing after them every five minutes, she was starting to miss the travelling and – dare she admit it – the Doctor himself. John was a great person, but he wasn't her best friend. Sometimes she wished there had been another way out of this that didn't involve the Doctor becoming a completely new person with an almost completely new personality.

Some things had crossed over from one man to another (like, for instance, his dislike in pears, which Donna had taken great joy in getting him to try a few days after he had changed), but there were too many differences to count. One thing that she had noticed was that John was much more of an openly emotional person than the Doctor. It was rare to see the Doctor willingly show his emotions and only certain things that he would allow get to him. Most of the time, he tended to hide away and forget about what had happened and move on. The last time that had happened was after the last time they had been on Earth when the TARDIS had taken them and Martha to Messaline and witnessed the creation and death of his daughter. He hadn't mentioned it since, choosing to avoid the subject altogether, but Donna knew that it still hurt to think about her. Had she not be shot, she would be with them right now, probably human and at a loss about who she was too considering her Time Lord heritage, but here nonetheless. And Donna knew that the Doctor knew that and thought about it more than he would care to admit.

Shaking herself out of her thoughts, Donna started to get ready for the day. Already she could hear her mum nagging her grandad about going up the hill with his telescope again. It was a sound that she was so familiar with, yet sounded strange to her ears after her being away for so long. After all this time, she still found it hard to adjust back to a normal life, even for a short period of time.

Once she had dressed and done her make-up, Donna picked up her phone again and dialed Martha's number. It was a godsend that Martha was around to help. When the Doctor had explained to her – albeit hurriedly – what was happening, she was so sure that she wouldn't be able to look after him alone. If the Family of Blood did find them, despite their best efforts to hide, then she knew she was going to need someone to lend a hand. It just so happened, that they had landed in a time and place where Martha was able to do just that. And she had been more than willing to keep an eye out when Donna had called and told her what had happened.

"Hello?"

"Hi Martha, was just wondering if you were busy today at all?"

"No, it's the weekend so I'm off until Monday and I don't have any plans. What's up?"

"John wanted to know if you wanted to join us for lunch? I'm meeting him at eleven since he's got something for my grandad, but then we decided to grab something to eat after. Fancy it?"

"Sure, I'll meet you at his, yeah? About the same time?"

"Perfect, I'll let him know. See you later, then."

"Bye!"

Putting the phone back down and in her pocket, Donna grabbed her bag and made her way out of the house, yelling to her mum that she was going to be borrowing the car for the day. All she heard as she left was the sound of her mother telling her that she was going to need the car later that evening before closing the door behind her.

God, if there was one thing that Donna hadn't missed, it was having to share a car with her mum. If only she had had a good enough job beforehand that could have bought her her own. But, a voice reminded her, if she had, she never would have met the Doctor. Now there was something that didn't bare thinking about.

Just outside of the city, there was a small field. It was mostly deserted, probably private land, though no one was ever certain. In the middle of the field was a small, abandoned hut. At one time, Donna assumed that it had been a storage area for whatever it was that went on here – no doubt something to do with cows. But it was long empty now. A few old tools, rusted and broken, lay scattered here and there, but other than that the space was empty.

Well, that was until a rather large, slightly worn, blue box had appeared in the middle of the hut a month ago. Now, there is stood, proudly and empty, hidden away from prying eyes; protected as much as a Time Ship could be from falling into the wrong hands.

Parking her car at the edge of the field, Donna trekked along the grass until she reached the small hut. She did her best to come up here most days – as did Martha – to check that everything was in order and that the TARDIS was still actually there. She had done so for a month now and nothing had been out of the ordinary. On occasion, Donna had toyed with the idea of just leaving it be, thinking it would be safe until everything went back to normal. However, she never did, because she knew, the moment she did, something would happen and she would only have herself to blame. She had promised the Doctor that she would look after him and, looking after him often meant looking after his ship too. It was the only thing he had left and Donna was not about to be the one responsible for it getting stolen by some lifespan-crazy aliens. Or any aliens in fact.

Going to the TARDIS also gave Donna the chance to re-watch the instructions that the Doctor had left her for when he was human. Some of them were completely bonkers ("number 17: don't let me watch Eastenders – I don't need to wake up knowing who slept with who"), and none of them had told her what to expect from the man he had become. She didn't even know who she would be to him when he had awoken. The last thing she would have needed was for him not know who she was. Thankfully, whatever residual awareness he had had kept her as his best friend. That had made things a lot easier. But, even now, she was still finding out new things about the man John Smith. For someone who wasn't meant to be a real person, he had one hell of a rounded backstory.

Donna eventually reached the TARDIS and used her key to unlock the doors. It was dark inside, but light enough to see where she was going. Nothing worked, only the scanner, and even that was only set to replace the message the Doctor had left. Anything else; anything that might send out a signal to those hunting them, had been switched off once the doors had closed that day a month ago. Nothing would be turned back on until the Doctor did it himself.

Making her way up the ramp, Donna paused as she saw the device hanging from the ceiling that had made the Doctor John Smith. She couldn't remember the name of it exactly – some kind of chameleon thing – but it hung in the TARDIS, reminding her every time of the horror she had witnessed as the Doctor's biology had been rewritten.

"Hold on, if you're gonna change your entire biological make up, isn't that going to hurt?""

Oh yes, it hurts."

"Surely there must be some other way?"

"Donna, those creatures can smell me. They'll chase us down across the whole universe to get me. If they do, they'll live forever and so many lives will be in danger. If I don't do this, then more harm will come then good. I have to stop being a Time Lord. I have to become human. There is no other way."

Shaking the memory from her head, Donna went over to the scanner and played the message again, skipping over the bits where he started rambling. She almost didn't realise what the time was and had spent more time than she had planned inside the ship. With one last look to make sure the scanner was off, Donna made her way out of the ship and back to her car.

At no point, on both her trips in and out of the hut did she notice the words: BAD WOLF written in spray paint on the wooden panels of the wall by the TARDIS. Though, even if she had, the words would have meant nothing to her. The only person in this universe who would know the significance of its meaning didn't even know who he really was at the moment but, if he did, he would know that from here on in, things were about to get that little bit more complicated.