I don't own anything other than my OC. Everything recognisable belongs to Russel T. Davis and the amazing team who write Dr Who!

It'd been two years, since my mother and sister died at Canary Warf, two years since I started my search for the man they called The Doctor. And those two years had brought me here... Adipose Industries.

Standing in a deserted corridor, I pressed the button on my vortex manipulator and beamed past the security checks before walking normally through the halls towards the lecture room. Glancing around me, I skirted around the reporters and sat down in one of the seats patiently to listen to the presentation.

"Adipose Industries, the 21st century way to lose weight." Miss Foster announced, "No exercise, no diet, no pain. Just lifelong freedom from fat. The Holy Grail of the modern age. And here it is," she held up a pill, "You just take one capsule, one capsule once a day, for three weeks. And the fat, as they say..."

"The fat just walks away," sounded from the main screen.

"Excuse me, Miss Foster, if I could," a reporter asked, "I'm Penny Carter, science correspondent for The Observer. There are a thousand diet pills on the market, a thousand con men stealing people's money. How do we know the fat isn't going straight into your bank account?"

"Oh Penny, if cynicism burnt up calories, we'd all be as thin as rakes," Miss Foster smiled, "But if you want the science, I oblige."

The computer sounded up again, "Adipose Industries." It announced, "The Adipose Capsule is composed of a synthesised mobilising lipase, bound to a large protein molecule. The mobilising lipase breaks up the triglycerides stored in Adipose cells, which then enter..." etc.

"100% legal, 100% effective," she announced after the presentation finished.

"But, can I ask, how many people have taken the pills to date?" Penny persisted.

"We've already got one million customers within the Greater London area alone," Foster smiled, "But from next week, we start rolling out nationwide. The future starts here. And Britain will be thin."

After the presentation, I wandered down the hall and into one of the call centres. A friend of mine from when we were in school was in one of the cubicles. "Hey Jay," I smirked as I sat next to him, "Favour?"

Depends what it is," he replied before answering the phone. "Good Morning, I represent Adipose Industries..."

I looked around the room, noticing a redhead woman who'd been at the presentation, she was talking to one of the other people. "The box comes with 21 days' worth of pills, a full information pack, and our special free gift," Jay was telling the person on the phone, "an Adipose Industries pendent." He picked one up and handed it to me, letting me look it over. "It is made of 18 carat gold, and it's yours for free."

I pointed at myself then the pendant making him nod so I could put it in the pocket of my jeans, he smirked. "What do you need?" he asked when he hung up.

"A list of your customers," I grinned, "please?"

"Sure," he laughed, "Doesn't come back to me though."

"Got it," I smiled, "Never met you before in my life. Where's the printer."

"By the plant over there," he nodded making me stand up to look and nod before seeing Miss Foster and crouching down so she couldn't see me.

"Excuse me, everyone, if I could have your attention," she called making everyone stand up, I leant down further. "On average, you're each selling forty Adipose packs per day. It's not enough. I want one hundred sales per person per day. And if not, you'll be replaced. Cause if anyone is good at trimming the fat, it's me. Now back to work."

With that she walked back out making me sigh, "Keep in touch?" Jay asked me, handing me his number on a piece of paper, "I printed it."

"Thanks Jay," I smirked, "I'll call you."

"Great," he smirked back as I headed over to the printer and picked up the paper before heading out.

"Hi there!" I greeted the middle aged woman cheerily, "You're Megan Scott? I'm Sarah Tyler and I represent Adipose Industries. And you are one of our valued customers."

"Oh, come on in then," the woman smiled before backing from the door, "Would you like a drink?"

"Tea would be great if you have it," I smiled before walking with her to the kitchen, waving to a little boy who was playing video games in the living room. "Your son yeah?"

"Dom, yeah," she smiled, "He's a really good kid."

"Looks it," I smiled, "So I was wondering about the pills, what's your personal experience been like?"

"It's been fantastic," she replied as she passed me my tea and sat opposite me at the table, "I started them Saturday and I've already lost four kilos."

"And no side effects?" I asked curiously.

"Nothing," she replied, "I just wake up and it's disappeared overnight. One kilo exactly every morning."

"Great," I gave a fake smile, "Working perfectly then. So you're doing exactly what the guidelines say?"

"Yeah," she nodded, "No alcohol, no extensive exercise... take it of a night in case of drowsiness."

"Wonderful," I smiled as I finished my tea, "Well, if you have any problems, just call us and we'll sort it out."

"Of course," she nodded as she stood up too, "I'll see you out."

"Great," I nodded before following, "Bye Dom!"

"Bye!" the kid called back and I walked out of the door.

"Bye Megan," I smiled.

"Bye Sarah," she smiled back before I walked off, she closed the door behind me.

As I reached the road, a man who looked exactly like mum had described ran past, without so much as a second thought, I was running after him. It didn't take long to catch up to him, especially when he stopped, looking confused. "Oi, space man!" I glared slightly making him turn around to see me.

"Do I know you?" he asked, confused.

"Probably not," I replied, "But you knew my mum, sister and best friend before they died at Canary Warf."

"Canary Warf?" he asked me, "Who are you?"

"Sarah Tyler," I replied simply, his eyes bulged and his jaw dropped slightly. "Yeah that Tyler. Now can you let me in on what happened to my family or do I have to follow you around to make you?"

He led me back to the TARDIS, blinking confusedly when I didn't bother doing the whole 'it's bigger on the inside' thing. "So... what did your mum say about me?" he asked curiously.

"Oh, this and that," I shrugged, "Basics. Ya know, alien, handsome, blue box, time travel."

"Hang on, Jackie said I was handsome?" he asked, confused, I just shrugged. "So, you get the whole alien thing. Well, your family isn't dead..."

I listened as he explained about the Cybermen and Daleks, as he told me about the parallel world and what happened on Bad Wolf Bay. "But they never mentioned you," he finished.

"Well, Rose and I never really got on," I replied, "I'm only her half sister, she didn't like that my dad was still alive and hers wasn't. We never really got past that, however much we wanted to."

He seemed to understand, and he also seemed to realise I didn't really want to talk about it anymore, he probably didn't either. Biting my lip, I watched as he looked at one of the gold Adipose Pendants through a magnifying glass.

Moving behind him, I looked over his shoulder, "Fascinating," he muttered.

"Looks like a bio-flip digital stitch, specifically for..." I stopped talking as he turned to give me a shocked look. His eyes fell to my wrist where my vortex manipulator was.

"Where did you get that?" he asked, shocked.

"I uh, I made it," I replied slowly, unsure as to why he looked so shocked.

"And you're human?" he asked me.

"As far as I know," I replied but before I could do anything else he had placed his fingers on my temple and my eyes snapped closed.

"You're human," he muttered, "That's for sure... but your brain capacity is, well, it's just impossible. You're brain seems like it could hold just about anything."

He pulled his hands away and I opened my eyes, giving him a confused look, "What does that mean?" I asked awkwardly.

"Well," he pursed his lips and scrunched his forehead, "I guess it means... do you want to stick around? Travel with me?"

A large smile broke across my face, "I'd love to!" I replied brightly making him chuckle slightly, which abruptly stopped when I threw my arms around him in a hug. I pulled away when I sensed his awkwardness, "Sorry?"

"No, it is okay," he laughed, pulling me back for another hug.

The next morning he took me back to Adipose and we entered through a fire escape on to a deserted corridor. We walked up to a random closet and he opened it before locking it behind us. It was kinda cramped, but I pressed myself up against one of the walls to give him some room as he opened a panel on the wall and started messing with the electronics in there.

Eight hours and forty minutes later he unlocked the door with his light thing and walked let me out in front of him. "What is that?" I asked, nodding to his little light thing.

"Screwdriver," he replied making me give him a look, "Sonic screwdriver, it does everything."

"Can I look at it when we get back to the TARDIS?" I asked him hopefully, "See how it works?"

"Yeah, sure," he nodded before leading me to the staircase to get to the roof. Once we got up there, him giving me another shocked look at my lack of gasping, we went to the window cleaner's cradle and descended.

We stopped by what looked like Miss Foster's office, and as I looked in, she and two men entered a Penny the reporter being dragged along. Ducking behind the part of the window blocked by curtains, I pressed my ear against the glass.

"This is ridiculous," Penny gasped.

"Sit there," Foster ordered.

"I'm phoning my editor," Penny threatened.

"I said sit!" Foster snapped, there was a sound of her hitting the chair.

"You can't tie me up!" Penny argued, "What sort of a country do you think this is?"

"Oh, it's a beautifully fat country," Foster replied making me bite my lip, "And believe me I've travelled a long way to find obesity on this scale."

"So come on then, Miss Foster, those pills." Penny asked, "What are they?"

"Well you might as well have a scoop, since you'll never see it printed," Foster smirked, "This, is a spark of life."

"And what is that supposed to mean?" Penny asked her.

"Officially, the capsule attracts all the fat cells and flushes them away," Foster told her simply, "Well, it certainly attracts them, that part's true. But it binds the fat together and galvanises it to form a body."

"Well what do you mean, body?" Penny asked as I shifted to look inside, keeping my ears strained to hear them.

"I am surprised you never asked about my name," Foster smirked, "I chose it well. Foster, as in foster mother. And these," she took a small 'thing' out of her draw and put it on the desk, "are my children."

"You're kidding me," I muttered at the same time as Penny.

"What the hell is that?" Penny demanded. Beside me, the Doctor rose to look through the window, and through the room, a woman appeared at the little window in the door.

"Adipose," Foster explained, "It's called an Adipose. Made out of living fat. Stripped from ordinary human..."

Next to me, the doctor had noticed the woman, who had noticed him too. I watched in amusement as they mouthed a conversation through the windows but as I grinned at the two my eyes fell on Foster who was watching, annoyed. "Ahem," I elbowed the doctor making him look, the woman doing the same.

"Are we interrupting you?" Foster asked loudly.

"RUN!" the doctor mouthed at the woman before locking the office with the sonic screwdriver and then using it to raise the platform to the roof. "C'mon."

We both vaulted over the side back onto the roof and ran into the building, heading downstairs... a few floors down, we stopped as the woman met us there. "Oh, my God!" she grinned, "I don't believe it! You've even got the same suit! Don't you ever change?"

"Yeah, thanks Donna, not right now," he muttered as I looked down the stairs, the guards were coming.

"We need move," I snapped before bolting back upstairs.

"Just like old times," the Doctor grinned at Donna before pulling her after me.

"Who are you?" she asked loudly as we emerged onto the roof, "Are you Rose?"

"No!" I replied, hopping into the cradle, "I'm Sarah, I met this guy today!"

"Great!" she grinned, "Donna Noble!"

"Nice to meet you." I smiled at her as the Doctor took his Sonic Screwdriver out.

"Well, I found you," she turned to him, "coz I thought, how do I find the Doctor? And then I just thought, look for trouble and then he'll turn up! So I looked everywhere, you name it – UFOs, sightings, crop circles, sea monsters. I looked, I found them all. Like that stuff about the bees disappearing, I thought, I bet he's connected."

I turned to the woman, she did exactly what I did, "Coz the thing is, Doctor, I believe it all now." She carried on, "You opened my eyes. All those amazing things out there, I believe them all. Well, apart from that replica of the Titanic flying over Buckingham Palace on Christmas Day, I mean that's gotta be a hoax!"

"It wasn't," I told her simply, "I was at Buckingham Palace then, figured I might be able to get the Royal Family out ya know."

"What d'you mean, the bees are disappearing?" the Doctor asked us.

"I don't know," Donna shrugged, "That's what it says on the internet." He climbed into the cradle with us. "Well, on the same site, there was all the conspiracy theories about Adipose Industries, I thought let's take a look!"

"In you get," the Doctor told her making her eyes widen.

"In that thing?" she asked, shocked.

"Yes in this thing," I replied with a smile.

"But if we go down in that, they'll just call us back up again," she complained.

"No no no, cause I've locked the controls," he told her, "I'm the only one who can control it. Unless she's got a sonic device of her own, which is very unlikely."

I held a hand out and helped Donna into the cradle, when we got halfway down, we started to accelerate making me clutch the side. The Doctor stopped it with his screwdriver making us loose our footing and fall to the base.

"Window," I commented, making him turn and try to open it with the screwdriver.

"Can't get it open!" he yelled.

"Well smash it then!" Donna yelled back, picking up a spanner and trying to smash the glass. "She's cutting the cable."

My head snapped up to where the cable had flared up, Foster was pointing a sonic at it, "Fuck," I grumbled before grabbing for the side, the cable broke before I could, making me tumble... Donna fell out of the cradle as the Doctor grabbed he side, his other hand clasping around my wrist before hauling me back in. "Donna!" we yelled.

"Doctor!" she yelled back, I looked to see her clinging to the broken cable.

"Hold on!" he shouted to her.

"I AM!" she gritted at him as he tried to pull her up by the cable. "Doctor!"

Looking up again, as I held to the cage of the cradle I noticed the other cable glowing. "Doctor!" I snapped making him look up to see, he pointed his screwdriver up and her device sparked making her drop it.

Wrapping my legs around the cage, I threw myself backwards, my hand wrapping around it before I brought myself back in. Climbing up next to the Doctor on the cable, I handed it to him and he opened the window, "I'm going to fall!" Donna shouted up to us. "This is all, your fault. I should've stayed home!"

"Give us a minute!" I shouted to her, "Just hold on!"

The Doctor helped me in through the window and we both ran down a few floors before running into Foster's office. "Is anyone going to tell me what's going on?" Penny asked us, she was still tied to the chair.

"You're a journalist?" the Doctor asked as he opened the other window

"Yes," she replied.

"Make it up," I told her as he grabbed Donna's legs.

"Get off!" she screamed.

"Stop kicking!" I shouted at her, "he's got you!"

He managed to pull her back in, me keeping them on their feet, "I was right, it's always like this with you, innit?"

"Oh yes!" he grinned, "And off we go."

His hands clasped around one of mine and one of hers before he pulled us out. "Oi!" Penny shouted.

"Sorry!" he replied as he popped back in and released her with the sonic, "Now do yourself a favour, get out!"

"C'mon," I shouted at him, grabbing his arm and pulling him along with me and Donna, when we entered the Call centre though, Foster was there with the guards.

"Well then," she commented, taking her glasses off, "At last."

"Hello," Donna smiled.

"Hi," I grinned.

"Nice to meet you, I'm the Doctor," he waved at her.

"And I'm Donna," Donna smiled.

"Sarah," I grinned again.

"Partners in crime," Foster commented, "And evidently off-worlders, judging by your sonic technology."

"Oh yes," he grinned back, "I've still got your sonic pen. Nice, I like it. Sleek, it's kinds sleek."

He showed it to us making me laugh slightly, "Oh it's definitely sleek," Donna commented.

"And if you were to sign your real name," I started making them look at me, my eyes were on Foster, "that would be...?"

"Matron Cofelia of the Five-Straighten Classabindi Nursery Fleet." She replied, "Intergalactic Class."

"A wet nurse, using humans as surrogates?" I asked, raising an eyebrow.

"I've been employed by the Adiposian First Family to foster a new generation after their breeding planet was lost," Foster told us.

"What do you mean lost?" the Doctor asked, "How do you lose a planet?"

"Oh, the politics are none of my concern," she replied, "I'm just here to take care of the children on behalf of the parents."

"What, like an outer space super-nanny?" Donna questioned.

"Yes if you like," Foster replied.

"So... so those little things they're, they're made out of fat yeah?" Donna asked, "But that woman, Stacy Campbell, there was nothing left of her."

"Oh, in a crisis the Adipose can convert bone and hair and internal organs," Foster explained, "Makes them a bit sick, poor things."

"What about poor Stacy?" Donna snapped.

"Seeding a level 5 planet is against galactic law," I told her simply making them all give me confused looks.

"Are you threatening me?" Foster smirked.

"We're trying to help you Matron," the Doctor turned to her, "This is your one chance; cause if you don't call this off, then I'll have to stop you."

"I hardly think you can stop bullets," Foster smirked as the bodyguards aimed.

"No, hold on, hold on, hold on, one more thing, before... dying," I interrupted with my hands up. "Do you know what happens if you hold two identical sonic devices against each other?"

"No," she replied after a pause.

"I think I can guess though," I smirked before taking them both of the Doctor and aiming them at each other, pressing the buttons.

The sonic waves interfered with each other, amplifying them and rating an agonising, glass shattering noise. Donna pushed me slightly making me stop and the Doctor pulled me along with them.

"What was that?" he asked me, "How did you about galactic law?"

"How am I supposed to know?" I asked, "I figured I was making it up."

"C'mon," he muttered, pulling me along the corridor from that morning, he pulled the cupboard open.

"Well, that's one solution," Donna commented, "Hide in a cupboard. I like it."

The Doctor pushed the back open again, showing her the big machine inside the wall. "Hacking into this thing, cause the Matron's got a computer core running through the centre of the building, triple deadlocked." He started to explain.

"But now we've got this," I asked, handing him the sonic pen, "You can get in right?"

"She's wired up the whole building, we need a bit of privacy," he muttered, holding two sparkplugs together. "Just enough to stop them. Why she's wired up the tower block? What's it all for?"

We watched as he fiddled with some cables when the computer came online, "You look older," Donna commented.

"Thanks," he muttered as I tried to stay out of it.

"Still on your own?" she asked him.

"Yeah," he nodded, "Well no, I've got Sarah as of today, and I had this friend, Martha she was called. Martha Jones. She was brilliant... and I destroyed half her life. But she's fine, she's good. She's gone."

"What about Rose?" Donna asked, making me look up. The Doctor's eyes landed on me.

"She's still lost," he replied, "I thought you were going to travel the world?"

"Easier said than done," she replied, "It's like I had that one day with you and I was gonna change. I was gonna do so much. Then I woke up the next morning, same old life. It's like you were never there. And I tried. I did try, I went to Egypt. I was gonna go barefoot and everything. And then it's all bus trips and guidebooks and don't drink the water and two weeks later you're back home. It's nothing like being with you. I must have been mad turning down that offer."

"What offer?" he asked confused.

"To come with you," she replied.

"You'd come with us?" he asked.

"Oh yes, please," she grinned.

"Right!" he grinned.

"Inducer activated," the computer started.

"Oh no," he muttered, before starting to go faster, "So far they're just losing weight, but the Matron has gone up to emergency pathogenesis."

"That's when they convert..." Donna started.

"...skeletons, organs, everything." I finished, "A million people are gonna die!"

"I've gotta cancel the signal," the Doctor groaned pulling out his pendant and taking the end off to reveal a chip. "This contains the primary signal. If I can switch it off the fat goes back to being just fat."

He hooked it up, "Inducer increasing," the computer stated.

"No no no! She's tripled it!" he panicked, "I need... haven't got time! It's too far, I can't override it! They're all gonna die."

"Is there anything we can do?" Donna asked him.

"Sorry Donna, this is way beyond you," he replied, "Gotta triple the base pulse, I can't..."

I raised an eyebrow and turned to him, "What do you need?" I asked him quickly.

"Two more capsules," he replied, "But I've only got the one." He turned to the switches and tried to move them all as I pulled my pendant out, Donna did the same.

"Ahem!" I cleared my throat making him look up, a grin spread across his face as he took them both and plugged them in... the lights went off. "Woo!"

He pulled the two of us into a hug as we laughed in relief, but we pulled away when a loud horn sounded. "What the hell was that?" Donna asked.

"It's the nursery," the Doctor replied as I moved to the screens.

"When you say nursery, you don't mean a creche in Notting Hill," Donna asked.

"Nursery ship," I answered for him.

"Incoming signal," the computer told us before an alien language appeared on the screen, the Doctor appeared at my shoulder making me move over slightly.

"Hadn't we better go stop them?" Donna asked.

"What is it?" I asked quietly.

"Instructions from the Adiposian First Family," he replied, "She's wired up the tower block to convert it into a levitation post." His eyes scanned the transmission, "Oh, oh we're not the one's in trouble now. She is!"

With that he bolted from the cupboard making us follow him. We reached the roof in time to watch the Adipose babies flying towards the nursery ship. "What you gonna do then? Blow them up?" Donna asked.

"They're just children," I replied, shocked.

"They can't help where they come from," The Doctor agreed.

"Oh that makes a change from last time," Donna commented, "That Martha must've done you good."

"She did," he nodded, "She fancied me."

"Mad Martha," Donna grinned, "Blind Martha. Charity Martha!" A smirk crossed my face at his put out face but I turned to see an Adipose baby waving at us. We waved back, "I'm waving at fat."

"Actually, as a diet plan, it sort of works," the Doctor muttered, "There she is."

We all ran to the edge as Foster soared in the air in front of us. "Matron Cofelia, listen to me!" the Doctor called.

"Oh, I don't think so, Doctor!" she smiled, "And if I never see you again, it will be too soon."

"Just listen," he yelled, "I saw the Adiposian instructions – they know it's a crime, breeding on Earth. So what's the one thing they want to get rid of? Their accomplice!"

"I'm far more than that," she smirked, "I'm nanny to all these children."

I looked up to see that all the Adipose babies had reached the ship, "Exactly," I said suddenly, "Mum and Dad have the kids now, they don't need nanny anymore!"

With that the blue light vanished and Foster fell down with a scream. A small whimper escaped my throat as I closed my eyes and turned away. Gritting my teeth, I looked up at the ship to see the Adipose waving goodbye.

Down on the street, the sirens of the ambulances and police blared. Lost in his thoughts, the Doctor threw the sonic pen into the bin. "Oi, you three!" Penny the journalist called making us turn to see her hopping out of the building, still tied to the chair. "You're just mad, do you hear me? Mad! And I'm gonna report you... for madness!"

"Yeah you do that," I muttered sarcastically.

"See some people just can't take it," Donna commented.

"No," the Doctor agreed.

"But some people can," Donna smirked, "So then – TARDIS! Come on!" With that she grabbed his hand and pulled him away, making me trail behind them.

It didn't take long for us to get to the alley where the TARDIS was, there was a car there too. "That's my car! That is like destiny! And I've been ready for this." Donna grinned opening the boot, it was full of suitcases.

"I packed ages ago, just in case. Cause I thought, hot weather, cold weather, no weather..." She was loading the bags into the Doctor's arms, "...he goes anywhere, I've gotta be prepared."

She tossed a hatbox on the top, "You've got a...a...hatbox?" he asked, confused.

"Planet of the Hats, I'm ready!" she replied with a big grin.

A smirk crossed my face as I watched him stood by the TARDIS surrounded by suitcases, quite serious. Donna was babbling at the door, beaming, oblivious to his mood. "Do I need injections though, do I? Like when you go to Cambodia, is there any of that? Cause my friend Veena went to Bahrain, and..." I bit my lip and she caught sight of his expression, "You're not saying much."

"No, it's just... It's a funny old life, in the TARDIS," he told her.

"You don't want me," she asked quietly, obviously upset.

"I'm not saying that," he tried to explain.

"But you asked me," she sighed, I looked from her to him, he looked just as sad as she did. "But you don't need me, you have Sarah."

"No, I just..." he started, "The last time, with Martha, like I said it... it got complicated." He sighed, "And that was all, my fault. I just want a mate."

"Just just want TO MATE?" she asked shocked and disgusted making me chuckle and bite my knuckle to silence it.

"I just want A mate," he replied, quickly.

"You're not mating with me, sunshine!" she snapped at him.

"He means friend Donna," I laughed, "He wants a friend."

"Well just as well, because I'm not having any of that nonsense," Donna sighed, "I mean you're just a long streak of... nothing. You know, alien nothing."

"There we are then," he sighed before looking at me for assurance.

"Not interested either dude," I said holding my hands up. "Way too old for me. I mean you look about thirty-six."

"Okay," he nodded.

"We can come?" Donna asked.

"Yeah, course you can, yeah," he grinned smiling at the two of us. "I'd love it."

"Ooh, that just..." she ran to him to hug him before remembering the conversation we'd just had. "Car keys!"

"What?" I asked, confused.

"I've still got my mum's car keys! I won't be a minute," she laughed before running away. We both watched her before collecting the luggage and taking them into the TARDIS.

It didn't take long before she came back in, "Off we go then!" she grinned at us.

"Here it is, the TARDIS." He told her, "It's bigger on the inside than it is on the outside..."

"Oh, I know that bit," she interrupted, "Although frankly, you could turn up the heat."

"So, whole wide universe, where do you want to go?" he asked us.

"Oh, I know exactly the place," she replied.

"Which is?" I asked hopefully.

"Two and a half miles, that way," she pointed making me raise an eyebrow.

The Doctor took us there and we opened the door and Donna waved to her grandfather who was looking through a telescope. Grinning to the Doctor, we both moved to the door to wave too before we zoomed away.