A/N: Disclaimer: Why would RTD hire me?! I'm a fifteen-year-old freakish fangirl!

Yes, ANOTHER one. These useless pieces of fic just pour out of my ears. Many apologies. I have no idea how long this is gonna be, probably pretty short depending on what I do :/

Chapter 1 – Becoming You

The Doctor admittedly was a genius at times and Rose would do anything for him. She would trust him even if he was wired up to a lie detector; she would put her life on the line for one of his silly little plans in a heartbeat and she would even chase the impossible to save his life, but right now even Rose was in serious doubt.

"Erm, and what is that exactly?" Rose asked, trying to hide her nervousness as she stared at the thing the Doctor held in his right palm, looming over her bed like a mad axe murderer.

"This?" he asked in a bright voice, holding up the strange black sphere with tendrils sticking out of it, still wiggling with life. "This is a Hashmou, and it's gonna make you better!"

Rose sincerely doubted that. She trusted him and all but this was going over the top. Okay, so she'd been laid her in her mother's flat with a pulsating headache and painful stomach for just over three days now, down with some kind of infection and Jackie blamed the Doctor, of course.

"All those strange alien foods everywhere! Red peas! Blue bread!" she had said, "don't think I don't know Doctor!"

She continued to eye the device warily from underneath a mess of hair, still curled into a ball with a hot water bottle pressed to her hurting stomach. "How's it work?"

He grinned, sitting down on the end of the bed and transferring half of the disgusting looking monster to the other hand, so it was split.

"It'll copy the virus from you and give it to me, I'll speed up the process so I'm only sick for a few hours which'll give my antibodies plenty of time to develop, after which I'll take a few of them and transfer them into you. That way they'll be able to duplicate, stick onto the antigens, clump 'em together, the cells gobble 'em up and eliminate the virus untiiiil…" – he paused for dramatic effect – "…et voilà! One healthy Rose Tyler!

"Why's that thing gotta be so…" She eyed it again with disdain. "…Squelchy."

The Doctor looked aghast. "Hey, I'll have you know that's an insult! They're just like spiders, one of the cleanest species in existence – they just look a little off the part, that's all. Spiders clean and preen themselves regularly, catch flies and dust yet all you humans do is scream at them. I mean, if they looked like bunny rabbits you'd welcome them into your homes."

"I don't mind spiders."

The Doctor cocked his head to one side at her, expression one of vague amusement. "Oh yeah? As I seem to recall when you found a spider in the TARDIS…"

Rose blushed, deep in embarrassment. "It surprised me. It was sittin' on my pillow just as I was 'bout to get in…"

"And that was an excuse to scream, run down the corridor to the kitchen where I was, scream some more, grab me by the arm, drag us both under the kitchen table and almost choke me to death?"

She shrugged weakly with a smile. "Just do it, whatever it is. I'm fed up of being in one place all the time."

He grinned back. "Ask and ye shall receive." He winked and placed one of the black squelchy monsters first on his head. Rose giggled. He looked like an idiot. He reached up with the other and placed it carefully on her head, and Rose felt the cold dampness of its slime as its tentacle wound themselves around her head and it stuck itself, fast. She could feel it pulsating and oozing yet more slime.

"Ready?" he asked, but didn't even wait for her reply as he triggered the process. Suddenly he began to feel faint and unnaturally cold – reality being just a dream. Why? This wasn't right…this wasn't right at all…

He lost his sense of balance and fell helplessly back onto Rose's bed, not making a sound but able to hear Rose's alarmed voice ringing in his ears.

He fainted clean away, Rose not far behind him.

Well, that one had gone wrong.

The Doctor woke up, bleary eyed and unfocused. He stared up at the holes in the ceiling for a moment, not really wanting to get up but knew he had to check on Rose's wellbeing. He strained his heavy head to look to the side, expecting to see Rose Tyler lying in the bed but instead he went rigid with shock.

"Uh oh," he muttered, though what came out was a high-pitched girl's voice, specifically that of Rose Tyler's. He was staring down at himself, already knowing that Rose's mind was in his body as his mind was in Rose's body. He paused for a moment, giving Rose in his body a small shove. "Rose? Wake up."

"Talkin' to yourself sweetheart?" came a voice from outside the closed door and the Doctor realised with a degree of dread that it was Jackie Tyler. Oh please, no. Any time but now. The door opened and the woman herself stepped through, holding a tray with a bowl of porridge and a cup of tea on. "You okay?"

"Umm…err…" he stuttered, caught off guard. "Yeah…" he said before quickly adding, "…mum."

"What's wrong with the Doctor?" she suddenly asked, looking down at the peacefully sleeping body of the Doctor. "'E said 'e'd got a cure, it's 'ardly time for a nap!"

"He…" he paused, trying to think of a plausible explanation. "Neuroses in the frontal lobe exerted a massive force of energy, burning out his glucose reserves causing a temporary neural shut down," he'd said before he could stop himself. Jackie stared at him blankly, seeing her daughter.

"'Scuse me?" she asked, confused. He mentally kicked himself.

"He was tired," he finally surmised, expecting a full interrogation for those three words but much to his surprise and delight Jackie didn't investigate. She was shaking her head in bemusement.

"I swear sweetheart if you 'ang around that alien much longer you'll turn into 'im…"

He frowned as she handed him the tray. "I don't really think so, mum."

"But 'e's bloody well gorgeous, I'll give 'im that."

His eyes shot wide open: part shock, part terror. "Umm…"

Jackie was watching her daughter's body, laughing. "Oh don't try and deny it, I know you like 'im. I may be old but I know the look."

"What look?"

She laughed. "The way your eyes light up when you look at 'im."

He just stared.

"Oh, don't worry, 'e gives you the look too."

"I do not!" the Doctor said before he could stop himself. Thankfully Jackie wasn't listening, adjusting his body in which Rose currently occupied on the bedsheets to make it more comfortable.

"And don't think I didn't see you peekin' through the doorway at Christmas when I was changin' his clothes!" she finished off as she crossed back to the door and gave him a wink, before stepping outside and closing the door.

"Eurgh…!" the Doctor moaned softly as he curled in on himself, retching at the pure disgustingness of the situation. "Arrggh…"

"Doctor?" his own voice suddenly asked from next to him and the Doctor looked down to see his own body's eyes shooting wide open with long, thin fingers snapping up to trace over the face in disbelief. "Oh my God what's happened to me?!"

"Rose shush," he hushed her quickly, placing his finger on her lips. "Calm down. We've switched bodies but I'll reverse it, I swear I'll reverse it."

She stopped, paused, and rested her hand on her chest. "I've got two hearts!"

"How'd you think I feel? I've got one heart! We have to reverse this before your mother finds out!"

"Why can't we tell her?"

He paused, swallowing nervously. "She's…told me things Rose. I think it would be best for the both of us if she never found out."

She half-smiled, somehow already guessing what her mother had been saying, but not letting on. "So how do we reverse this?"

"We need to get the Hashmou back," he replied, getting out of the bed and scouting around the room. "It's scarpered. If we don't get it back we'll never switch back our minds. Did you see where it went? Rose?" He turned, seeing Rose staring at him. "What?"

"You move like a man!" Rose suddenly said, pulling up to sitting position. He rolled his eyes, suddenly exasperated for no reason.

"Of course I move like a man I've been one for nine hundred years!" he snapped, and then realised what he'd said. Rose realised this too, and started to giggle.

"You're gettin' mood swings!" she mocked.

"Am not!"

"Are too!"

"Am not!"

"Are-"

Jackie exploded into the room. "What the 'ell are you two blabbin' 'bout? Rose, get back into bed now!"

The Doctor stood still, somehow forgetting he was now Rose. He heard Rose cough slightly before he realised it meant him. He moved hastily back to the bed, climbing in between the warm sheets. "Sorry…mum."

"It's alright sweetheart." She looked at the tray she's given him and tutted, mother-like. "You haven't eaten any of your breakfast. A nice cuppa tea and some porridge, that's what you need."

The Doctor suddenly realised how ill he felt. Rose hadn't been lying at any rate; his head was aching as was his stomach, but he did rather fancy a cup of tea. Jackie turned to Rose, seeing the Doctor.

"Oh, so you're awake now are you? What 'appened to that cure?"

The Doctor watched Rose's eyes flicker towards his own as she pulled herself to her feet, almost staggering in surprise at the large height advantage she now had over her mother.

"Umm…" she started, garbling for a moment as he had done himself.

The Doctor saved her, "the Doctor realised it was for Merusian flu mum, he got a bit confused." Rose sighed relief and shot the Doctor a half-smile of gratitude.

"Yeah, that's me mu…Jackie, sorry."

Rose never realised before how much danger the Doctor was in every time he walked into the Tyler flat as her mother glared at her with true contempt. She staggered a little.

Jackie suddenly looked concerned, reaching up to Rose's forehead. "Oh sweetheart, you're not sick too are you? I can deal with Rose bein' grumpy but not you as well!"

"No, I'm fine," she said quickly, instantly trying to smile and looking casual. "Absolutely…" – she ventured for a 'Doctor-like' word – "…dandy?"

"Well, if you're sure. I'll stick the kettle on for you."

"Thanks," Rose replied as Jackie left, closing the door behind her. She turned to the Doctor, hands on hips. "We have got to sort this out."

"I know…" the Doctor muttered, sliding out of bed again and ducking to check under the bed once more for the Hashmou. "It's just…it's not in here."

"Which means it could be anywhere," Rose finished, sighing loudly. "On the Earth."

"It wouldn't have strolled far. For one thing they're very slow, I would doubt if it's even out of the estate yet."

"So we've gotta act like nothin's happened?"

The Doctor nodded. "Yep. So for starters, you've got to be a little more like me."

"And you've got to stop making me out to be a man," Rose pointed out.

"Alright Rose Tyler," he straightened, broadening a grin. "It's time to teach you how to be a man."

She grinned back. "And Doctor, I hope the Universe is listenin', because it's time to teach you how to be a woman."