A/N: Welcome back! Hope you're enjoying this story so far! Get ready for the next adventure!

I do not own Doctor Who. All that I own is this story and my OC.

This chapter takes place during School Reunion.

Please review and no flaming is tolerated. Enjoy :)

FIGHT FOR YOUR RIGHT

"You wake up late for school, man, you don't wanna go.
You ask your mom, "Please?" but she still says, "No!"
You missed two classes and no homework.
But your teacher preaches class like you're some kind of jerk."
– The Beastie Boys: 'Fight for Your Right' (Licensed to Ill [1986])

The TARDIS
Console Room

(Flashback)

Fingers typed furiously across a keyboard, causing words to fly across the screen. Katy was sitting cross-legged on the jump seat, focused on doing an essay for her history course, with the Doctor hovering nearby, tinkering with the TARDIS and lending help whenever his girlfriend needed it. Suddenly, her phone rings from where she had placed it on top of the console, causing Katy to jump because of how loud it was, and the Doctor to abruptly sit up … and smack his head on the underside of the console.

"I should really turn down the volume on that thing." Katy groused, reaching for her phone.

"I second that." The Doctor bitched, sliding out from underneath, and rubbing at his head as he glowers at the phone in Katy's hand. She pulls a surprised look on her face when she sees caller ID.

"It's Mickey." Katy announced, and the Doctor rolls his eyes.

"Ugh, what does he want now?" He grumbles, getting to his feet. Katy presses the answering button and puts the phone to her ear.

"Hey, Mick." Katy answers, pleasantly. She listens for a moment, before frowning. "What? For real?" The Doctor silently walked forward and stood beside the jump seat, waiting patiently for Katy to finish her conversation with Mickey. "You've never done something like this before, what's with the turn around?" Katy cracked a grin at what Mickey said, before laughing a little. "Alright, I'll pass it on to the Doctor, and see what can be done." The Doctor raised an eyebrow. "See you soon. Bye!" She hung up and looked up at her curious boyfriend.

"Pass what on to the Doctor?" said alien asked, guardedly.

"Mickey suspects something alien related is happening at a local high school back home." Katy responds, earning a look of intrigue from the Doctor. "Figured you'd wanna check it out."

"Check what out?" Rose piped up, walking into the Console room, annoyed at the close proximity her sister and the Doctor were standing in.

"Mickey says something's wrong at a local school." Katy answered, and Rose looked a little hurt.

"Why'd Mickey call you?" Rose asked, and Katy looked a bit awkward.

"How should I know?" Katy shrugged. "Why don't you ask him?" She powers down her laptop and jumps down from the jump seat. "How about it, Doctor? You gonna check it out?"

"Depends. What exactly did Mickey say was happening?" the Doctor questioned, not exactly chomping at the bit to go and investigate something at a high school, only for the 'something wrong' to turn out to be something utterly pointless.

"Apparently, the students have been showing signs of unusual intelligence and record-breaking high-test results." Katy reported back.

"So, what's wrong with that?" Rose asked, frowning in confusion. "Doesn't exactly sound very alien, or supernatural."

"It does if the school in question was ranked amongst the lowest test scoring schools in the past few months." Katy pointed out, flatly. "Students don't have sudden spurts of intelligence that quickly."

"Sounds intriguing," the Doctor nodded, looking interested. "Alright, I'll bite. Let's go and check it out."

Physics classroom
South London
2006.

So that's how the Doctor and Katy found themselves walking into a classroom, underneath the guise of a physics teacher and his student teacher. All it took was a simple flash of the psychic paper and some slightly tedious paperwork, and their undercover mission was well on its way. They both got a few odd stares from some of their 'students', but others merely just sat in their seats, and looked at the Doctor with either a blank face or looked very attentive. The Doctor sets down his briefcase and stands behind the desk, looking out at the students with a cheery smile on his face.

"Good morning, class. Are we sitting comfortably?" He asks, patiently waiting for all the kids to give him their full attention. Katy pulls up a chair beside the desk and sets down her laptop. The Doctor turns, picking up a piece of chalk and writes 'physics' in huge block letters on the board. "So, physics. Physics, eh? Physics. Physics. Physics! Physics." Katy looks up from what she was typing on her laptop and raised an eyebrow. "Physics, physics, physics, physics, physics, physics, physics. I hope one of you is getting all this down."

Katy snorts with barely suppressed laughter, earning looks from both the students and the Doctor.

"Sorry," She apologised, flushing in embarrassment. The Doctor gives her an amused scowl, before turning back and continuing on with the lesson.

"Okay, let's see what you know," He clears his throat. "Two identical strips of nylon are charged with static electricity and hung from a string so they can swing freely. What would happen if they were brought near each other?" A small boy with glasses immediately puts his hand up. "Yes, er, what's your name?"

"Milo."

"Milo! Off you go." The Doctor grins at the boy.

"They'd repel each other because they have the same charge." Milo responds confidently.

"Correctamundo!" the Doctor crows loudly, then makes a slightly horrified face. "A word I have never used before and hopefully never will again."

'Please don't…' Katy seconded him, looking at him with bemusement. She returned to her homework.

"Question two," the Doctor continues. "I coil up a thin piece of microwire and place it in a glass of water. Then I turn on the electricity and measure to see if the water's temperature is affected. My question is this…" He pauses for dramatic effect. "How do I measure the electrical power going into the coil?" Milo's hand shoots up again, while the other students look bored. "Someone else?" The Doctor has no takers. "No? Okay, Milo, go for it."

"Measure the current and PDs in an ammeter and a voltmeter."

"Two to Milo," the Doctor complimented the boy, sounding mildly impressed. "Right then, Milo, tell me this," He focuses intently on Milo who blinks back at him patiently. "True or false. The greater the dampening of the system, the quicker it loses the energy to its surroundings."

"False," Milo's answer was given without any hesitation. Katy looks up, sensing something odd coming from the boy, and pays attention to the following battle of wits.

The Doctor shoots out another question.

"What is non-coding DNA?" He asks, and Katy blinks at him in astonishment. That wasn't even a physics question. But sure enough…

"DNA that doesn't code for a protein." Milo responds promptly.

'What the…?'

"Sixty-five thousand, nine hundred and eighty-three times five?" The Doctor randomly blurts out, frowning also.

"Three hundred and twenty-nine thousand nine hundred and fifteen." The entire class is suddenly very alert and looking between the Doctor and Milo with stunned faces. These were impossible questions, hard for most university students to answer without looking it up.

"How do you travel faster than light?"

"By opening a quantum tunnel with an FTL factor of thirty-six-point seven recurring." Milo answers, and both Katy and the Doctor dropped their mouths open in shock.

Canteen

Katy made her way down to the school canteen, squirming uncomfortably when her stomach made unpleasant growling noises, demanding to be fed. Her eyebrow rose when she stepped inside, expecting to find a room filled with rowdy students enjoying a hot meal with their friends. What she was confronted with, was a room indeed full of students enjoying a hot meal, but not a loud voice was heard. Instead, they were sitting in groups talking quietly with each other – an unnaturally well-behaved group of children. The brunette headed for the dinner line and picked up a tray, falling into step behind the students.

"Ready for dinner?" A familiar voice asks. Katy must've jumped ten feet into the air, and she spun round and glared at an amused Doctor who was grinning at her.

"Was that necessary?" Katy groused, mildly annoyed.

"I thought so." The Doctor replied, with a bit of playful banter.

Katy shook her head and lifted her tray to be loaded down with what was on offer that afternoon. A small helping of chips was scooped onto the tray, followed quickly by a large helping of mashed potatoes and gravy. Katy gives her sister, who was the one who had slopped the potatoes on the plate with an unimpressed glare on her face, an awkward smile. The Doctor, however, just grins at her and leads Katy away.

"Hot chips?" Katy questioned, surprised, as she and the Doctor take a seat at a nearby vacant table. "Didn't expect a school to serve this. Aren't they trying to encourage students to choose healthier options?" She spears a chip onto her fork and nibbles on the end. She pulls a face at the unusual taste. "Where's Jamie Oliver when you need him?" The Doctor snorted with amusement but appeared to agree with her.

"This tastes a bit odd, have you noticed?" He asks Katy, before discarding the half-eaten chip back onto the tray and scooping up a forkful of peas instead and popping it in his mouth.

"Yeah. I think the oil they're using might be a bit off." She glances over to see if one of the dinner ladies was free and goes to get up from her seat. "Maybe, I should let them know—"

"Two days," Rose bitches, coming over and wiping down their table with a rag as she glowers at them. Katy sinks back down into her chair and decides to continue eating for now. The Doctor just looks at Rose, slightly unimpressed with her whinging.

"Sorry, could you just? There's a bit of gravy." He indicates to the table, and Rose rolls her eyes and wipes at some spilled gravy. "No, no, just, just there." He points to another puddle of gravy.

"Two days, we've been here." Rose hisses her displeasure, and this time the Doctor rolls his eyes.

"Blame your boyfriend. He's the one who put us onto this," the Doctor retorted, spooning some mashed potatoes onto his fork. "And he was right, wasn't he?" He looks over to Katy for confirmation.

"Yeah, completely," Katy nodded. "There was this kid in one of the Doctor's classes today. He got every answer right."

"With knowledge way beyond planet Earth." The Doctor added, looking thoughtful. However, Rose's attention had wondered towards the ignored piles of hot chips on both her sister and the Doctor's trays. Her eyes lit up.

"You eating those chips?" She hinted, and Katy rolled her eyes and pushed her tray towards her sister so she could help herself. The blonde had always been a sucker for hot, salty, vinegary chips.

"Knock yourself out," Katy stated, and Rose immediately plucked one from the tray and popped it into her mouth. The Doctor made a face.

"They're a bit different."

"I think they're gorgeous," Rose moaned happily, taking a seat across from them and helping herself to another. "Wish I had school dinners like this."

"Fat chance, Rose," Katy retorted. "Even if we did, mum wouldn't have let us." The Doctor glanced about the canteen with a slightly uncomfortable look on his face.

"It's very well behaved, this place." He commented. "I thought there'd be happy slapping hoodies. Happy, slapping hoodies with ASBOs. Happy, slapping hoodies with ASBOs and ringtones. Huh? Huh?" Both Katy and Rose look at him strangely, earning a grin in return. "Oh, yeah. Don't tell me I don't fit in." The Doctor looked proud of himself, and Katy reached over and patted the back of his hand, looking slightly condescending.

"Of course you do, sweetie."

"You are not permitted to leave your station during a sitting." All three of them look up to see the stern-faced head dinner lady, scowling at Rose, who flushed with slight embarrassment.

"I was just talking with these teachers." Rose defended herself, meekly.

"Hello!" the Doctor greeted the woman, brightly, while Katy just offered her a polite smile.

"They don't like the chips," Rose tells her, and almost immediately the woman looks at the Doctor and Katy defensively.

"The menu has been specifically designed by the headmaster to improve concentration and performance." She explains to them, harshly.

"Okay. We'll take your word for it." Katy rushes to placate her.

"Now, get back to work." The dinner lady snaps at Rose, and flounces away. Rose throws a resentful glare at the woman's back, before huffing and getting to her feet.

"See? This is me. Dinner lady." She muttered distastefully, heading back towards the kitchen.

"I'll have the crumble," the Doctor calls out, teasingly. Rose smirks, despite feeling annoyed about the entire situation.

"I'm so going to kill you." She calls back. Katy frowns thoughtfully at the Doctor.

"Didn't that strike you as a bit odd that she took our criticism so personally?" She questions her boyfriend, who looks at her curiously. "I mean, her reaction was a bit extreme."

"Nah, I won't worry about it. I think we've got bigger problems to deal with." The Doctor reassures her with a smile. Katy nodded, deciding to let it go for now. If the Doctor wasn't worried, then why should she be?

Kitchen

Pretty soon, class had resumed. This left an extremely bored and resentful Rose to help clean and do the drying up with the other dinner ladies … and also keep a sharp eye out for anything unusual. It was agreed before this adventure that Mickey would contact Rose with information and vice versa, while the Doctor and Katy maintained their cover as teacher and student teacher respectively. Rose flipped the tea towel she was holding over her shoulder, as she set aside a dry serving tray to be put away and reached for another one. She spots the other dinner ladies coming through the back door. Rose pauses in the act of drying when she sees that they are wheeling a large cooking oil drum through.

Usually, this wouldn't be seen as odd … if it wasn't for the weird symbols stencilled on the side of the drum, and the fact that all of them were wearing breathing masks and heavy-duty protective gauntlets.

'What the hell?' Rose thought, frowning in confusion. Wasn't that a bit of overkill for a barrel drum of cooking oil?

"Careful," Jackson, one of the head dinner ladies, warns. "Keep it steady. Don't spill a drop." Rose dumps the tea towel on the counter and walks cautiously towards the wall and peers around it, curiously. "I said, keep it steady. Careful. That's it. Easy now. Steady." Rose's phone rings in her pocket, and she scrambles to answer it before it could give away the fact that she was spying on them. Thankfully, none of them notice. Jackson quick marches her team back out the door. "Right. Second barrel. Quickly now!"

"What you got?" Rose answers her phone.

"Confirmation." Mickey responds.

Library

In an undisclosed area in a public library nearby the school, Mickey is using the internet to gather clues for the Doctor, Katy, and Rose.

"I just got into the army records," Mickey explains, frowning at what he was reading on the computer screen. "Three months ago, massive UFO activity." He types something into the computer. "They logged over forty sightings. Lights in the sky, all of that." He growls in frustration when an access denied message flashes on screen. "I can't get any photos, because then it gets all classified and secret." He bitches. "Keeps locking me out." Mickey glares at the message: Torchwood Access Denied.

Kitchen

"Tell you what, though." Rose continues whispering so that she isn't overheard. "Three months ago, turns out all the kitchen staff were replaced." Jackson and the other dinner ladies return with the second barrel of oil, causing Rose to frown at them in bemusement. "And this lot are weird."

Library

Mickey smirks triumphantly at what Rose tells him.

"See? There's definitely something going on." He states, smugly. "I was right to call you lot home."

"I thought maybe you called me home just, well, just to call me home." Rose stated, sounding hopeful. Mickey scoffs and rolls his eyes.

"Do you think I'd just invent an emergency?" He sounded dubious.

"You could've done," Rose responded defensively.

"That's the last thing I'd do," Mickey sets Rose straight. "Because every time I see you, an emergency just gets in the way." He was surprised by the lack of guilt he was feeling by saying this to Rose. "Besides, I also wanted to see Katy. I miss seeing my best mate everyday—" Mickey is cut off when he hears a woman screaming in agony over the line.

His eyes widen.

"I've got to go." Rose states hurriedly.

"Rose, what is it?" Mickey attempts to ask, but he is hung up on.

Kitchen

During Rose's conversation with Mickey, the second barrel of oil the kitchen staff were attempting to wheel into the kitchen toppled over, splashing one of the women, who had the misfortune of being too close to the spray. The second the oil touches her skin, she starts screaming.

"Get her up, get her up!" Jackson hisses, and the other staff haul the woman to her feet and hustle her into the office. Rose raises an eyebrow when she sees the blinds being pulled down. She immediately dials 999 on her phone, just as Jackson sees her and sticks her head out to address her. "What're you doing?"

"Calling an ambulance," Rose responds like it should've been obvious.

"No need. She's quite alright." Jackson says, dismissively. Suddenly there is a whoomph! noise; like something had been set alight just as easily as setting fire to rice paper, and the same woman screams. Rose's eyes widen in shock. "It's fine. She does that." Jackson again dismisses before going back into the smoke-filled office.

"What the fuck?" Rose mutters underneath her breath, before looking back at the spilt oil.

She gapes in surprise: the oil had eaten right through the metal of the oil drum.

Staircase

The headmaster – hereafter called Finch – guides a female investigative reporter along on a guided tour through the school. The woman, who looked to be in her mid to late forties, nodded at him as he continued his conversation with her.

"Our work here," Finch states, laying on the charm. "My improvements aren't confined to the classroom. Oh, no, no, no, no, no. We've introduced a new policy. School dinners are absolutely free, but compulsory. Do try the chips." He suggests to the woman, hereafter referred to as Sarah-Jane, who smiles at him politely.

"Oh, I'd love to," Sarah-Jane offers him a white-lie. "Thank you. And it's got to be said, the transformation you've brought about is amazing." She compliments him. "I mean, maybe you're working the children a little bit too hard now and then, but I think good results, they're more important than anything." She muses, earning an approving smile from Finch.

"Exactly," He agrees. "You're a woman of vision, Miss Smith." Sarah-Jane couldn't help but smirk just a little.

"Oh, I can see everything, Mister Finch. Quite clearly." She wasn't fooled by him for a minute.

Staff room

The Doctor and Katy had no class to teach during this period, so they decided to relocate to the staff room to get the facts from other teachers on their coffee breaks. They make a beeline for the tea and coffee, make one for themselves, and head over to perch on a nearby table with a packet of biscuits between them, as they listened to the school's math teacher, Mr Parsons, telling them about his out-of-character students.

"Yesterday, I had a twelve-year-old girl give me the exact height of the Walls of Troy in cubits." He explained to them, shaking his head, and looking mystified.

"And it's ever since the new headmaster arrived?" the Doctor questioned him, chewing on a biscuit.

"Finch arrived three months ago," Parsons tells the couple with a disbelieving shake of his head, like he still couldn't believe that their new headmaster even existed. "Next day, half the staff got flu. Finch replaced them with that lot…" He points towards a group of smartly dressed teachers, all wearing permanent scowls on their faces, and standing well apart from the other chatty and gossipy teachers. "… except for the teacher you replaced, and that was just plain weird, her winning the lottery like that."

"How's that weird?" Katy asked, elbowing the Doctor in the side to stop him from smirking mischievously and probably give them away.

"She never played," Parsons confirmed. "Said the ticket was posted through her door at midnight." He shrugged before turning and heading back over to the coffee and tea for a refill.

"Hmm. The world is very strange," the Doctor commented, airily and acting way too innocent.

Katy smirked and shook her head, reaching for another biscuit, before engaging in a playful tug-of-war with the Doctor when he accidentally reaches for the same biscuit, and ends up doubling over in quiet laughter when he begins to tickle her underneath the ribs to get her to let go. Finch and Sarah-Jane chose that moment to walk in, and Sarah-Jane immediately spots the couple, smiling in amusement when she sees their antics.

'Aww, young love…' She couldn't help but think, as Finch clears his throat to grab everyone's attention.

"Excuse me, colleagues. A moment of your time," He calls out, causing nearly all heads to swivel in his direction. "May I introduce Miss Sarah Jane Smith," The Doctor's head immediately looks up and over at Sarah-Jane, and his eyes widen in shock. Katy raises an eyebrow, curiously. "Miss Smith is a journalist who's writing a profile about me for the Sunday Times," Finch continues, a little boastfully. "I thought it might be useful for her to get a view from the trenches, so to speak. Don't spare my blushes." He turns and leaves the room, and the teachers go back to their previous activities or conversations, leaving Sarah-Jane to wonder about the room.

The Doctor was yet to look away from her, making Katy feel slightly jealous and wary about the woman.

"Do you know her?" Katy questioned him. But the Doctor ignores her, just as Sarah-Jane suddenly catches his eye and walks over to them.

"Hello!" Sarah-Jane greets the Doctor with an outstretched hand for him to shake. He immediately latches on, pumping it up and down enthusiastically.

"Oh, I should think so." The Doctor agrees with a warm grin. Sarah-Jane turns her attention towards Katy, taking back her hand from the Doctor and offering it to her also.

"Hello!"

"Hi," Katy politely acknowledged her and shakes Sarah-Jane's hand also.

"And who are you two?" Sarah-Jane prompts, politely. The Doctor blinks in confusion before realising that he had been asked a question.

"Hm? Er, Smith. John Smith." He offers his pseudonym to her.

"Caitlyn Tyler."

"Lovely to meet you," Sarah-Jane says to Katy, before looking at the Doctor with a slightly nostalgic smile.

"John Smith. I used to have a friend who sometimes went by that name." Sarah-Jane remarked.

"Well, it's a very common name," the Doctor shrugged nonchalantly, still giving her a slightly scary grin that was beginning to concern Katy, who didn't want to intentionally scare the poor woman off. Luckily, Sarah-Jane didn't seem fazed by the Doctor's strangeness.

"He was a very uncommon man," Sarah-Jane acknowledged, before turning to move along. "Nice to meet you."

"Nice to meet you," the Doctor parroted. "Yes, very nice. More than nice. Brilliant." He gushed, and Katy looked a little hurt at the enthusiasm, something that Sarah-Jane noticed and looked concerned about.

"Er, so, er, have you worked here long?" Sarah-Jane asked, trying to act professional.

"No. Er, it's only my second day." The Doctor responded.

"Mine too." Katy piped up, feeling a little cross. The Doctor seemed to remember that she was there and hooked an arm around his girlfriend's shoulders.

"Oh! Yes, of course. I almost forgot. I'm helping to mentor Katy here for her teaching degree." The Doctor used their alibi for Katy's presence in the classroom alongside him, should anyone ask. Sarah-Jane immediately perked up at this.

"Oh, so you're both new, then." She walks a little closer to them, so they couldn't be heard by any eavesdroppers. "So, what do you both think of the school?" Both the Doctor and Katy raise their eyebrows at Sarah-Jane's question. "I mean, this new curriculum? So many children getting ill. Doesn't that strike you as odd?"

"That doesn't sound like someone just doing a profile." The Doctor points out, smirking a little.

"Well, no harm in a little investigation while I'm here." Sarah-Jane retorts with a secret little smile.

"No. Good for you." The Doctor compliments, sounding impressed. Sarah-Jane waves at them both before moving away. "Good for you. Oh, good for you, Sarah-Jane Smith." The Doctor mutters proudly, loud enough for only Katy to hear. Katy scowls at the Doctor, before pasting a tight smile on her face.

"At the risk of sounding like a broken record, Doctor; do you know her?" Katy repeats her question from before, and the Doctor turns and looks at her.

"Sarah-Jane?" the Doctor confirms. "Yes, of course. She's an old companion of mine."

"Oh," Katy blinked in surprise.

Corridor

When night fell, it was time to do an extra bit of sleuthing after hours at the school. The Doctor leads Katy, Rose, and Mickey into the darkened and deserted school. Rose looks around with unease.

"Oh, it's weird seeing school at night," She comments, making a face. "It just feels wrong. When I was a kid, I used to think all the teachers slept in school." Katy places a hand on her sister's shoulder, drawing the blonde's attention towards her.

"If it makes you feel better, Rose, I doubt you're probably the first person to have these thoughts, nor dare say will you be the last." Katy humours her, before walking towards the Doctor, who for once wasn't wearing his usual enthusiastic smile on his face, that he normally wore when on adventures like this.

"All right, team," the Doctor whisper-shouts at the three of them before making a face at what he said. "Oh, I hate people who say team. Er, gang. Er, comrades…" he trails off before shaking his head dismissively and coming to the point. "Anyway, Rose, go to the kitchen; get a sample of that oil." The blonde nods. "Mickey, the new staff are all Maths teachers; go and check out the Maths department." Mickey looked a tad apprehensive, but nodded, nonetheless. "Katy and I will check out Finch's office. Let's meet back here in ten minutes."

Rose scowls a little at the fact that Katy was being singled out by the Doctor to go along with him to investigate, but lets it go when the Doctor abruptly and defiantly snatches Katy's hand, as though anticipating an objection from Rose, and takes off down the corridor, disappearing round a corner. Mickey observes Rose's reaction with a look of irritation that he quickly hides when she turns towards him with a smile.

"You going to be all right?" Rose asks him.

"Me?" Mickey scoffs with false bravado. "Please. Inflitration and investigation? I'm an expert at this." He walks off in a random direction, leaving Rose standing there looking amused; and knowing damn well that he'd be back to ask directions. And sure enough… "Where's the Maths department?" He asks sheepishly. Rose stifles a giggle.

"Down there, turn left, through the fire doors, on the right." She directs him, and Mickey nods, flushing a little from embarrassment.

"Thank you."

Meanwhile, in another corridor, Sarah-Jane had also broken into the school to do her own brand of sleuthing. Having already chased something that was flying down a nearby corridor, and lost sight of it, she gives up the search and approaches a nearby storeroom. She opens the door and goes in, before freezing in her tracks when she comes face to face with the TARDIS. Sarah-Jane's eyes widen in shock and she cups her hands over her mouth, unaware that the Doctor (and Katy) were standing behind her.

"Hello, Sarah-Jane." The Doctor calls out, calmly. She spins around and her mouth drops open in surprise and realisation.

"It's you," Sarah-Jane whispers obviously stunned. "Oh, Doctor. Oh, my God, it's you, isn't it?" He smiles and Sarah-Jane returns it before giving him a quick eye sweep. "You've regenerated."

"Yeah. Half a dozen times since we last met." He confirms with a nod, and Katy looks at him with surprise.

"Have you really?" She mumbles, and the Doctor turns his head and looks at her with affection. Sarah-Jane is surprised to see Katy standing there with him.

"Another companion of yours?" She inquires, not unkindly. Katy rubs her arm a little awkwardly.

"Er, sort of." She admits, and Sarah-Jane raises an eyebrow at the odd answer.

"What do you mean, sort of?"

"Katy is one of my companions … and my girlfriend." The Doctor explains, looking slightly sheepish.

"Oh, wow. Never thought this would happen, considering…" Sarah-Jane trailed off, and the Doctor nodded in acknowledgement.

"Your companions get younger, it seems." Sarah-Jane teased lightly, and both the Doctor and Katy shared a smirk between them. "What?"

"It's a grey area." The Doctor differs. When Sarah-Jane still looked confused, Katy elaborated.

"Let's just say, I'm older than I look. Much older."

"Well, you look incredible." Sarah-Jane complimented the Doctor, who grins.

"So do you."

"Huh," Sarah-Jane scoffs. "I got old. What are you two doing here?"

"Well, UFO sighting, school gets record results. Couldn't resist a look. What about you?" The Doctor questioned.

"The same," Sarah-Jane confirms, before tears started welling up in her eyes, alarming Katy a little. "I thought you'd died. I waited for you and you didn't come back, and I thought you must have died." She confessed, and the Doctor winced at the reminder before explaining.

"I lived. Everyone else died." He revealed, then glanced at Katy. "Well, almost everyone."

"What do you mean?" Sarah-Jane frowned.

"Everyone died, Sarah. But by some strange twist of fate, there turned out to be another survivor." He indicates to a slightly awkward Katy. Sarah-Jane studies the brunette curiously.

"You're a Time Lady?"

"Dormant," Katy confirmed, fingering the heart locket around her neck. "And locked safely away in here." Sarah-Jane looked like she wanted more information, but Katy stubbornly shut down. Both the Doctor and she had already revealed enough, and Katy didn't feel comfortable revealing more to someone who was virtually a complete stranger. Sarah-Jane reluctantly let it go.

"I can't believe it's you." Sarah-Jane whispers, looking joyfully at the Doctor; stirring up more jealous emotions from Katy, who was getting annoyed with the cow eyes Sarah-Jane was giving her boyfriend, and immediately feeling surprised with herself that she was acting this way. Suddenly, they hear Mickey scream and Katy charges off to aid her friend, while the Doctor and Sarah-Jane grin at each other with excitement. "Okay, now I can!"

Katy bursts out of the storeroom, nearly colliding with Rose in her haste to go and investigate what had spooked Mickey. The blonde gives her sister a 'seriously?' look, and turns to address the Doctor, who was quick on his girlfriend's heels.

"Did you guys hear that?" Rose questions Katy and the Doctor, before locking surprised, then casts suspicious eyes on Sarah-Jane who had followed the couple out of the storeroom. "Who's she?"

"Rose, Sarah-Jane. Sarah-Jane, Rose." The Doctor introduces the two women absently, watching Katy rush off after giving her sister an apologetic grimace. Sarah-Jane smiles politely at Rose.

"Hi. Nice to meet you." Sarah-Jane acknowledges Rose, who doesn't return the smile or the handshake Sarah-Jane offers her. The older woman raises an eyebrow at Rose's rudeness and turns to talk instead to the Doctor. "You can tell you're getting older. Your assistants are getting younger." She teases him, causing the Doctor to roll his eyes and go off after Katy.

Rose glowers at Sarah-Jane.

"I'm not his assistant."

"No? Oh, well. My mistake then." Sarah-Jane apologises, already sensing that the blonde was going to be a handful, and not taking much of a liking towards her.

Classroom

Mickey was in the process of trying to stuff some vacuum-packed rats back into a storage locker that he had opened to look inside, feeling like an idiot for practically screaming like a little girl in his shock. Katy runs around the corner, almost skidding in her haste, looking worried.

"Mickey? Are you alright?" She demanded, then frowns at the large pile of rats scattered around her friend's feet.

"Sorry! Sorry, it was only me." Mickey acknowledged, sheepishly. "The Doctor told me to investigate, so I started looking through some of these cupboards and all of these fell on me." Katy bit back a smirk and stooped down to help him.

"Let me help." She said, just as the Doctor, Rose, and Sarah-Jane finally showed up. Katy glances over her shoulder at them. "Everything's fine. Something just startled Mickey, is all." Rose blinks down at the vacuum-packed rats with wide eyes.

"Oh, my God, they're rats. Dozens of rats. Vacuum-packed rats." She blurted out, in revulsion. The Doctor frowned in annoyance, stooping down to pick up one and held it out for Mickey to see.

"And you decided to scream?" He stated, a little mockingly. Mickey looks defensively back at him.

"Like Katy said, it took me by surprise!"

"Like a little girl?"

"Doctor…" Katy groaned in exasperation. He just couldn't resist the chance to needle Mickey.

"It was dark! I was covered in rats!" Mickey scowls. The Doctor continues to smirk at him.

"Nine, maybe ten years old. I'm seeing pigtails, frilly skirt—"

"Oh, come on. Be fair!" Katy jumped up and got in-between them before Mickey could swing a fist at her boyfriend for being mocked. "Even you'd scream if you weren't expecting it, Doctor. Give him a break!"

"Oi! Can we focus?" Rose blurted out, looking irritated. "Does anyone notice anything strange about this? Rats in school?"

"Well, obviously they use them in Biology lessons," Sarah-Jane pointed out, matter of fact. "They dissect them. Or maybe you and your sister haven't reached that bit yet. How old are you two?" She asks, curiously. Katy opened her mouth to explain that she and Rose were both nineteen, almost twenty, and that they didn't dissect rats because Rose had dropped out of school by then, and Katy hadn't taken that particular class during school.

But Rose beat her to it.

"Excuse me, no one dissects rats in school anymore. They haven't done that for years." Rose sneers, unpleasantly. "Where are you from, the dark ages?"

"Rose!" Katy looked mortified, while Sarah-Jane looked taken aback. The Doctor immediately moved to change the subject before a catfight could break out, which he desperately wanted to avoid at all costs.

"Anyway!" He interjects, aiming a stern look at Rose, who flushes and glowers at Sarah-Jane. "Moving on. Everything started when Mister Finch arrived. We should go and check his office." He gestures towards the way they had come, and Rose immediately turns and goes, followed by both Katy and Sarah-Jane, with the Doctor and Mickey trailing behind them.

Corridor

Katy was feeling extremely uncomfortable where she was sandwiched between Rose and Sarah-Jane, as they all strode with a determination down the corridor to investigate the headmaster's office. She could feel the sympathetic gazes on the back of her head, coming directly from the Doctor and Mickey, and the hostile emotions coming from her sister.

"I don't mean to be rude or anything," Rose began, sounding anything but sincere. "But who exactly are you?" Katy cringed, then closed her eyes and gathered up all her patience. Thankfully, Sarah-Jane took Rose's question in her stride.

"Sarah-Jane Smith. I used to travel with the Doctor."

"Oh," Rose responded, looking thoughtful. "Well, he's never mentioned you." She smirked, looking a bit smug, and grunted when Katy elbowed her in the ribs. Sarah-Jane's face fell a little, and she looked back at the Doctor questioningly. The Doctor froze, looking like a deer caught in headlights, before quickly recovering, and reaching for a plausible explanation.

"Oh, I must've done." He insists, gaining a bemused look from both his former companion and his girlfriend, the latter knowing quite well that Sarah-Jane had never been mentioned before now. It was obvious that he was clutching at straws. "Sarah-Jane. Mention her all the time."

"Hold on," Rose pretended to really think about when the last time Sarah-Jane had been mentioned since meeting the Doctor last year. She shakes her head. "Sorry. Never." She insisted, as the smug smirk reappeared on her face and she picked up the pace, obviously knowing she had stirred up a bloody hornet's nest. Sarah-Jane threw a hurt look at the Doctor, who looked at her sheepishly.

"What, not even once? He didn't mention me even once?" Sarah-Jane walked to keep up with Rose, with an exasperated Katy trailing along behind them. The Doctor glared angrily at the back of Rose's head for throwing him underneath the metaphorical bus when Sarah-Jane turned away.

"I'm pretty sure I did. You just probably don't remember." The Doctor yelled down the corridor to Rose, as he also picked up the pace. Mickey couldn't help but grimace sympathetically at the Doctor's back.

"Oh, great. We're really in for it now…" He mutters, warily.

Outside the Headmaster's office

A quick zap of the Doctor's sonic screwdriver on the lock to the headmaster's office later, and they finally had access inside. The tension between the Doctor, Rose, and Sarah-Jane was almost stifling, and both Katy and Mickey stood apart from them feeling extremely … awkward.

"It just occurred to me," Katy suddenly speaks up, gaining the attention from everyone else. "Maybe those rats Mickey found were food?"

Rose made a face.

"Food for what?" She asked, just as the Doctor gets the door open and cautiously sticks his head inside. He takes a thorough look around the room, but just as he was about to withdraw and declare it a dead end; he looks up at the ceiling and freezes.

"Rose," the Doctor calls out, calmly. "You know you used to think all the teachers slept in the school? Well, they do." He confirmed, and Rose, Katy, Mickey, and Sarah-Jane come over to see for themselves the Doctor's discovery. Hanging from the ceiling by their clawed feet, were giant bat like creatures … and there were a lot of them.

"Bloody hell…" Katy curses softly with wide eyes.

"No way!" Mickey panics and seizes Katy's hand, pulling her protectively down the corridor as they run away from the headmaster's office. Rose is quick to follow, leaving the Doctor and Sarah-Jane to follow at a more sedate pace. The Doctor quietly closes the door, but not before accidentally waking one of the creatures, who shrieks angrily at the interruption.

School yard

When Mickey and Katy finally reach the school yard outside, Katy manages to yank her hand free from Mickey's grasp, scowling at her best friend in annoyance. She rolls her shoulder gingerly.

"Jeez, Mickey. You nearly pulled my arm from its socket." Katy complained, wincing slightly.

"Sorry," He apologises, slightly out of breath. Mickey looks fearfully at the main entrance, just as Rose, the Doctor, and Sarah-Jane immerge from it. "But I am not going back in there. No way." He declared, firmly. Rose looked equally as freaked.

"Those were teachers." She exclaimed, as the Doctor turned and frowned thoughtfully at the school, obviously disturbed by their finding.

"When Finch arrived, he brought with him seven new teachers, four dinner ladies and a nurse." He mused.

"Thirteen," Katy realised after doing a mental calculation in her head. "Thirteen big bat people. But what are they doing here?"

"I don't know. But I'm gonna find out." The Doctor promised and turned to head back into the school. "Come on!" Mickey immediately balked at the idea.

"Come on? You've got to be kidding?!" He protested. The Doctor rolled his eyes, impatiently.

"I need the TARDIS. I've got to analyse that oil from the kitchen." He explained, holding up a vial of golden liquid that Rose had supplied for him. However, Sarah-Jane immediately intercepted him.

"I might be able to help you there," She announced. "I've got something to show you." Sarah-Jane turns and heads off at a brisk walk towards the nearby carpark, pulling out her keys from her pocket. Intrigued, the Doctor follows her, curious about what Sarah-Jane had to show him after all this time apart. Katy, Rose, and Mickey exchange looks between them before walking after them.

Carpark

Sarah-Jane stopped behind the boot of her silver Volkswagen Passat and pressed a button on her key fob. The car bleeped to life, and she immediately pulled open the boot door. Inside, there was a sort of lump covered with a tartan blanket, which the Doctor frowned at with confusion … until Sarah-Jane pulled it away, revealing…

"K9!" The Doctor exclaimed excitedly when he clapped eyes on a small, dog-shaped metal robot, before turning and beckoning his girlfriend, Rose, and Mickey over. "Katy Tyler, Rose Tyler, Mickey Smith; allow me to introduce K9." He stated, happily. "Well, K9 Mark Three to be precise."

"A robot? Didn't expect that." Katy commented with a pleasantly surprised look on her face.

"Why does he look so … disco?" Rose questioned making a disinterested face. Both the Doctor and Sarah-Jane look at her, aghast.

"Oi! Listen, in the year five thousand, this was cutting edge." The Doctor pointed out, defensively. He turned and looked at Sarah-Jane for an explanation. "What happened to him?"

"Oh, one day, he just, nothing." Sarah-Jane admitted, looking a little concerned.

"Well, didn't you try and get him repaired?" The Doctor asked, and Sarah-Jane just gave him a flat look in response.

"Well, it's not like getting parts for a Mini Metro," She pointed out. "Besides, the technology inside him could rewrite human science. I couldn't show him to anyone." The Doctor nodded, accepting her reasons, before turning his attention back on K9.

"Ooh, what's the nasty lady done to you, eh?" He cooed at the inanimate robot dog, and 'scruffed' him about the ears like a real dog. Rose and Mickey just looked at him like he was nuts, while Katy and Sarah-Jane looked at him with exasperated fondness. None of them are aware that they are being watched by something off in the distance, on a nearby rooftop.

"Look, no offence, but could you two just stop petting for a minute? Never mind the tin dog. We're busy." Rose exclaimed in obvious frustration.

"Rose, you need to work on your patience, love." Katy advised, as Sarah-Jane closed the boot lid and headed straight for the driver's side of the car. The Doctor called shotgun, while the three young adults clambered into the backseat, immediately feeling like they were stuck in a sardine can together as the car started up and pulled out of the school parking lot.

A giant alien bat creature flies across the face of the full moon.

Coffee Shop

Sarah-Jane drives the four of them towards the nearest coffee shop, where immediately, the Doctor and Sarah-Jane huddled together at a nearby table, catching up and tinkering away at K9, trying to fix him. Katy, Rose, and Mickey make a beeline for the counter, where Rose orders some hot chips and Katy requests some hot tea. Both Katy and Rose glance frequently over to the table occupied by the Doctor and Sarah-Jane, only for two entirely different reasons: Rose, because she was harbouring some serious jealousy issues towards Sarah-Jane, whom she believed was yet another rival for the Doctor's affections, while Katy was just content letting the old friends catch up with each other, her own brand of jealousy not completely gone, but manageable. In her eyes, holding onto these petty feelings wasn't going to do her any favours should the Doctor find out.

Mickey had a very smug look on his face, directed towards Rose.

"You see, what's impressive is that it's nearly been an hour since we met her," He indicates towards an oblivious Sarah-Jane, still talking animatedly with the Doctor, who was scanning K9 with his sonic and making adjustments here and there. "… and I still haven't said I told you so." He smirked and leant against the counter with his arms folded across his chest.

"I'm not listening to this." Rose retorted, drumming her fingernails on the counter as she impatiently waited for her order. Katy just rolled her eyes in response to her sister's immature behaviour. However, it seemed that Mickey wasn't quite finished with taunting Rose.

"Although, I have prepared a little 'I was right' dance that I can show you later." He offered, earning a quick glower from Rose who immediately dropped it when the cashier returned to the counter, holding a small, white polystyrene container of fresh hot chips, which she handed to Rose, and a medium-sized takeaway cup of steeping tea and a dinky little cup of milk, which she gave to a grateful Katy. It was a fairly brisk night, and the warmth from the tea was a godsend.

"That's two quid to you," She nods at Rose who promptly hands her the coins and moves away to a nearby table with Mickey following her. "And £1.30 to you, love." Katy smiles and hands the coins to the woman. "Sugar sachets around the corner, if you need any." She tells Katy who nods but doesn't head for it.

"You don't know what you're talking about." Rose insists to Mickey, before stabbing at a chip with her plastic fork and stuffing it into her mouth.

"He probably doesn't," Katy piped up as she blew softly on her scalding hot tea so she didn't burn her tongue. "But if I were you, I'd go easy on the chips." She suggests, prompting Rose to pause mid-chew with a bit of the chip still sticking out of her mouth. Rose swallows her mouthful and looks resentfully at her sister, before redirecting her glance towards the Doctor and Sarah-Jane.

On the Street

On a building adjacent to the coffee shop, Finch was standing on the roof, observing the Doctor working on K9, curiously. The large bat-like creature from before swoops around, but instead of being frightened, like a normal person would've done if they had seen such a creature, Finch merely calls out to it.

"Come to me," He commands. "Come to me." The creature obeys Finch's command and lands soundlessly beside the man before both crouch on the edge of the rooftop; both looking like stone gargoyles as they continue their stakeout.

Coffee Shop

With soft, but calculating eyes, Sarah-Jane observes the Doctor working on K9 diligently. She smiles, seeing the man she once knew inside this 'younger' version, before the smile once again fades when she remembers her last encounter with him before he disappeared from her life.

"I thought of you on Christmas Day," Sarah-Jane tells the Doctor, who glances up briefly from his work to look at his old companion with a warm smile on his face. "This Christmas just gone? Great big spaceship overhead. I thought, oh yeah, bet he's up there." The Doctor nods a little.

"Right on top of it, yeah." He confirms as Sarah-Jane turns and discreetly looks over at the three young adults perched on a nearby table, giving them space to catch up, but also casting curious gazes over as well. Or at least Katy and the nice, but wary young man were, and the young brunette gave Sarah-Jane a polite smile and a nod when she caught Sarah-Jane's eye, which the older woman returned. But Rose? Well, she was another story entirely. The blonde chose, rather childishly in Sarah-Jane's opinion to blatantly ignore her, still scarfing down her hot chips, and glaring at the opposite wall.

"And Katy?" Sarah-Jane asked. The Doctor looked over at his girlfriend with a fond smile.

"She was there, with Rose too." He confirmed. Sarah-Jane nodded in acknowledgement, before her smile turned into a slightly hurt and confused frown.

"Did I do something wrong?" She couldn't help but wonder, and the Doctor glanced up and raised an eyebrow at her, inquiringly. "Because you never came back for me. You just dumped me." The Doctor looked a little irritated with his former companion's question. Not that he was irritated with her, just the entire situation at that point of his existence. He didn't want to hurt her feelings unintentionally, but sometimes the bitterest truth was better than lying to save face.

"I told you," He explained. "I was called back home and in those days humans weren't allowed."

"I waited for you," Sarah-Jane confessed and the Doctor winced, immediately feeling uncomfortable. "I missed you." He tried to brush it aside dismissively.

"Oh, you didn't need me. You were getting on with your life."

"You were my life," She reminded him.

The Doctor paused and looked at Sarah-Jane with sad, guilty eyes. He knew even back then that Sarah-Jane had feelings for him, which was an unfortunate side effect with some of the companions he had had back in those days, since he technically couldn't return those feelings because he already had a wife and children waiting for him back in Gallifrey. Obviously, those days were ancient history, and his family burned with the planet he had chosen to sacrifice to defeat the Daleks. And now he was free to love again, if he wished. The Doctor glances over at Katy, who was oblivious at that moment, in the middle of a conversation with Mickey and a half-listening Rose … and smiled.

"You know what the most difficult thing was?" Sarah-Jane questioned him, bringing his attention back on K9 and away from his sad memories. "Coping with what happens next, or with what doesn't happen next. You took me to the furthest reaches of the galaxy. You showed me supernovas, intergalactic battles, and then you just dropped me back on Earth. How could anything compare to that?"

"All those things you saw, do you want me to apologise for that?" The Doctor frowned defensively at her. Sarah-Jane immediately attempted to help him understand, realising how her words sounded to him.

"No. But we get a taste of that splendour and then we have to go back."

"Look at you, though. You're investigating." The Doctor pointed out, trying to look at the positive side of the situation. "You found that school. You're doing what we always did."

"You could have come back," Sarah-Jane insisted.

"I couldn't," the Doctor retorted gently.

"Why not?" She prompted, but the Doctor chose to ignore the question and continue working on K9. Sarah-Jane saw the avoidance tactic and knew when to take a hint and let it go. However, a smirk spreads across her face. "It wasn't Croydon. Where you dropped me off, that wasn't Croydon."

"Where was it?" The Doctor asked, looking surprised.

"Aberdeen."

"Right," the Doctor flushed in embarrassment. "That's next to Croydon, isn't it?" Suddenly, K9 came back to life in a series of bleeps and colourful lights. The Doctor beams happily. "Oh, hey. Now we're in business!" His loud exclamation attracts the attention of the three young adults at their table, and they immediately jump up and come over to investigate.

"He's working again?" Katy comments, curiously.

"Master," K9 speaks up with his computerised, robotic voice.

"I'll take that as a yes." Katy acknowledges, looking impressed, while the Doctor grins like a Cheshire cat.

"He recognises me."

"Affirmative," K9 agrees, wiggling his computer satellite-type ears in a dog-like fashion. Katy giggles.

"That is so cool!" She compliments, earning an appreciative smile from Sarah-Jane. The Doctor turns his attention to Rose and reaches out a hand to her.

"Rose, give us the oil." He requests, and Rose hands him the vial. But she attempts to stop him when he uncorks it and goes to dip his finger inside.

"I wouldn't touch it, though. That dinner lady got all scorched." Rose warns, and the Doctor shakes his head reassuringly.

"I'm no dinner lady. And I don't often say that." He states, as he scoops up a little of the oil onto his finger and smears it onto K9's probe when the robotic dog retracts it out to receive the sample. "Here we go. Come on, boy. Here we go." The probe retracts back into K9's body and there is a series of clicks and bleeps as he starts analysing the oil.

"Oil. Ex ex ex extract. Ana ana analysing." K9 says, glitching a little. Mickey couldn't help but grin in amusement also.

"Listen to him, man. That's a voice." He comments and grunts a little when Katy jabs him in the ribs with her elbow.

"Careful. That's my dog." Sarah-Jane scolds him, and Mickey flushes, looking properly chastised. A few minutes later, K9's analysis is finished.

"Confirmation of analysis. Substance is Krillitane Oil." K9 reports, and a look of dread passes over the Doctor's face.

"What's wrong?" Katy questioned.

"They're Krillitanes."

"Is that bad?" Rose piped up.

"Very," the Doctor confirms, gravely. "Think of how bad things could possibly be and add another suitcase full of bad."

"And what are Krillitanes?" Sarah-Jane asked, looking worried.

"They're a composite race," the Doctor explains. "Just like your culture is a mixture of traditions from all sorts of countries, people you've invaded or have been invaded by. You've got bits of Viking, bits of France, bits of whatever. The Krillitanes are the same. An amalgam of the races they've conquered." Katy, Rose, and Sarah-Jane paled. "But they take physical aspects as well. They cherry pick the best bits from the people they destroy. That's why I didn't recognise them. The last time I saw Krillitanes, they looked just like us, except they had really long necks."

"Charming," Katy pulled a face at the imagery.

"What're they doing here?" Rose asked.

"It's the children," The Doctor's eyes widened in realisation. "They're doing something to the children."

A/N: Part one is completed. Part two will be uploaded momentarily.
Stay tuned x