Day Two.

'That's not your normal coat.'

'We're in a school, Doctor, one of the worst places in the universe. I can't afford to ruin my favourite coat.'

The Doctor and The Wizard walked along a corridor chuckling, burst into a classroom and The Doctor took charge; 'Good morning, class. Are we sitting comfortably?'

The Wizard wasn't. She patted the inside of her long coat and began to fiddle with her sonic screwdriver.

'So… Physics.' The Doctor wrote it on the board in straggly capitals.

'Physics, eh?' He threw the pen to The Wizard, who caught it and set it down beside her.

'Physicsss. Phy-y-ysics. Physics. Physics, Physics, Physics, Physics, Physics, Physics. Physics!'

The Wizard rolled her eyes fondly.

'Hope one of you is getting all this down.'

The Wizard snorted in amusement.

'Okay! Let's see what you know. Two identical strips of Nylon are charged with static electricity and hung from strings so they can swing freely. What would happen if they were brought near each other?'

A boy put his hand up. The Wizard blinked at him.

'Yes! Er… what's your name?'

'Milo.'

'Milo! Of you go.'

'They'd repel each other because they have the same charge.'

'Correctamundo…! a word I… have never used before and hopefully never will again.'

The Wizard laughed and sat beside The Doctor on the desk.

'Question two. I coil up a thin piece of micro wire 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. How do I measure the electrical power going into the coil?'

She looked closely at the students. Again, Milo put his hand up and was the only one to do so.

'Someone else. Mmm…'

The class didn't move an inch.

'Nope? Okay, Milo, go for it.'

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

The Wizard and The Doctor watched him carefully. The Doctor started firing questions, though the answer came right back.

'Two to Milo. Right then, Milo, tell me this. True or False. The greater the dampening of the system, the quicker it loses energy to its surroundings.'

'False.'

'What is non-coding DNA?'

'DNA that doesn't code for a protein.'

'Sixty five thousand nine hundred and eighty three times five?'

'Three hundred and twenty nine thousand nine hundred and fifteen.'

The Doctor glanced at The Wizard. 'How do you travel faster than light?'

'By opening a quantum tunnel with an FTL factor of thirty six point seven recurring.'

The Doctor lets his jaw drop and The Wizard looked at him in surprise.

'O-o-o-kay…,' she said, frowning at the boy in the second row.

They went down the line in the cafeteria and grinned at one particular lady as she served them mashed potatoes. It was The Wizard who was sympathetic and The Doctor who found it funny when Rose looked at them crossly. She came over to their table later and began to clean their it, really looking for an excuse to vent at The (far too chirpy) Doctor.

'Two days.'

'Sorry, could you just? There's a bit of gravy.' The Doctor teased.

Rose adjusted where she was wiping.

'No, no, just, just there.'

The Wizard kicked him under the table.

'Ow!'

'Two days, we've been here,' Rose complained, looking like her life energy was drained.

'Blame your boyfriend. He's the one who put us onto this. And he was right. Boy in class this morning, got a knowledge way beyond planet Earth.'

'Or humans,' added The Wizard.

'You eating those chips?'

'Knowledge beyond your species' comprehension and you're asking about chips?' said The

Wizard.

'Yes. Are you going to eat them?' Rose took one from The Wizard's plate.

The Doctor looked down at his plate and frowned. 'Yeah, they're a bit different.'

'I think they're gorgeous. Wish I had school dinners like this.' She sat down between the two at the end of the table.

'It's very well behaved, this place,' said The Doctor, looking round, 'I thought there'd be happy slapping hoodies. Happy slapping hoodies with ASBOs. Happy Slapping hoodies with ASBOs and ringtones, eh? Oh yeah, don't tell me I don't fit in.'

'I wasn't going to mention it,' said The Wizard, inspecting a chip. She shrugged and passed it to Rose.

A dinner lady came over, looking cross. 'You are not permitted to leave your station during a sitting.'

Rose quickly stood up. 'I was just talking to this teacher.'

'Hello!' The Doctor put a very happy, cheerful face on.

"Not helping!" The Wizard mouthed at him.

'He doesn't like the chips,' said Rose.

The dinner lady looked down at him crossly. 'The menu has been specifically designed by the Headmaster to improve concentration and performance.'

'What, by serving chips?' The Wizard muttered.

The Doctor's eyes quickly floated to hers and they raised an eyebrow at each other.

'Now get back to work!' The lady walked off.

Rose looked crestfallen and sighed as she left. 'See? This is me! Dinner Lady!'

'I'll have the crumble!' The Doctor called after her.

The Wizard laughed.

'I'm so going to kill you. Both of you!' Rose called back.

'Melissa.'

The Doctor and The Wizard turned their heads to look a couple of tables across at a tall teacher who had approached a table. 'You'll be joining my class for the next period. Milo's failed me, so it's time we moved you up to the top class.'

'Milo's failed him?' The Wizard said. The Doctor raised his eyebrows back at her.

'Kenny, not eating the chips?'

'I'm not allowed.'

'Luke. Extra class. Now.'

The teacher walked off and The Doctor and The Wizard watched him, Melissa and Luke leave the table in surprise. Then they notice the headmaster standing on the balcony above and watched as looked down, with pride and superiority.

The Wizard was perched on a table in the staff room passing The Doctor biscuits as they talked to another teacher.

'Yesterday, I had a twelve year old girl give me the exact height of the Walls of Troy in cubits.'

'And it's ever since the new headmaster arrived?'

Listening carefully, The Wizard ruffled through the biscuit tin.

'Finch arrived three months ago. Next day half the staff got flu. Finch replaced them with that lot.' He nodded to a few teachers chatting near some blue chairs. 'Except for the teacher you replaced and that was just plain weird, her winning the lottery like that.'

'How's that weird?' The Wizard asked, passing The Doctor another biscuit.

'She never played. Said the ticket was posted through her door at midnight.' The teacher walked away.

'Hmm,' The Doctor ate another biscuit. 'The world is very strange.'

'Excuse me, colleagues. A moment of your time.'

The Wizard and The Doctor did a double take when they saw Finch in the doorway, accompanied by someone they never thought they'd see.

'May I introduce Miss Sarah Jane Smith.'

The Doctor's face mirrored The Wizard's as they looked at her in wonder.

'Miss Smith is a journalist who's writing a profile about me for the Sunday Times.' He smiled around the room. 'I thought it might be useful for her to get a view from the trenches, so to speak. Don't spare my blushes.'

When Finch left Sarah Jane saw the kind looks on the two's faces and came toward them.

'Hello.'

'Oh, I should think so.' He was trying not to beam and scare her off.

'How do you do, Miss Smith?' winked The Wizard, using the words she and The Doctor had used when they first met her.

'And, you are?

'Hm? Er…,'

'Smith, he's John Smith,' said The Wizard, knowing The Doctor was having trouble, 'and I'm his sister, Emily Smith.'

'John and Emily Smith. I used to have friends who sometimes went by that name.

'Well, it's a very common name.'

'They were very uncommon people. Nice to meet you.' She held out her hand.

The Doctor shook it happily and beamed. 'Nice to meet you. Yes, very nice. More than nice.

Brilliant.'

The Wizard was beaming as well as she shook Sarah's hand.

Sarah looked around when she had finished shaking The Wizard's hand. 'Er, so, er, have you worked here long?'

'No. Er, it's only our second day.'

'Oh, you're new, then.' She looked around and sidled closer to them. 'So, what do you think of the school? I mean, this new curriculum? So many children getting ill. Doesn't that strike you as odd?'

'You don't sound like someone just doing a profile,' said The Wizard.

'Well, no harm in a little investigation while I'm here,' she said, smiling and walked away.

'No. Good for you. Good for you. Oh, good for you, Sarah Jane Smith.' The Doctor said.

When she was out of sight, The Doctor immediately turned to The Wizard and they grabbed each other by the forearms and jumped up and down excitedly.

'Evening, Mickey, ready to get this show on the road?'

'Breaking into school? Now that's something I don't want to miss.'

'Right then, off we go,' said The Wizard and pulled the lever of the Tardis.

They materialised and hopped outside.

When they were walking through the dark corridors, Rose grinned.

'Ohoo, it's we-i-rd seeing school at night. It just feels wrong. When I was a kid, I used to think all the teachers slept in school.'

The Wizard chuckled as The Doctor turned around by a staircase.

'All right, team. Oh, I hate people who say team. Erm, gang… Er…, comrades. Er… Anyway, Rose, go to the kitchen. Get a sample of that oil. Mickey, the new staff are all Maths teachers. Go and check out the Maths department. I'm going to look in Finch's office. Wizard?'

'I imagine Sarah Jane will have broken in so I'd better go look for her.'

'Alright, I'll come with you and we'll swing past Finch's office. Be back here in ten minutes.'

The Doctor and The Wizard took the stairs two at a time. The corridor was quiet until they heard a screeching sound. They paused for a moment, then went down the corridor at a quicker pace.

They saw Sarah Jane run across the corridor up ahead and without a word, changed their direction. They knew she'd find the Tardis.

Sure enough, she backed out of the storeroom a minute later into the music hall and turned around to see them standing side by side.

'Hello, Sarah Jane.'

'It's you! Oh, Doctor… Wizard… Oh, my God, it's you, isn't it?' She pointed at them. 'You've regenerated.'

'Yeah-.'

'-Yeah. Half a dozen times since we last met.'

'You look… incredible!'

'So do you,' they replied.

'Huh. I got old,' she took a step to the left. 'What are you doing here?'

'Well…'

'UFO sighting, school gets record results. We couldn't resist. What about you?'

She smiled. 'The same.'

All three laughed and suddenly Sarah grew sad.

'I thought you'd died! I waited for you and you didn't come back, and I thought you must have died!'

The Wizard held out and arm and Sarah ran into it, hugging her.

The Doctor sighed. 'We lived. Everyone else died.'

Sarah stood back and held The Wizard's hand. 'What do you mean?'

'Everyone died, Sarah.'

She shut her eyes and shook her head. 'I can't believe it's you.'

A scream immediately followed that, coming from behind The Timelords.

'Okay,' said Sarah as The Doctor and The Wizard turned back to look at her, 'now I can!'

The Doctor took Sarah's other hand. They smiled and ran out of the hall and nearly into Rose

'Did you hear that?' Rose noticed Sarah. 'Who's she?'

'Rose, Sarah Jane. Sarah Jane, Rose.' The Doctor was happy and hadn't considered that things might go the other way.

'Hi. Nice to meet you.' Sarah Jane took her hand from The Doctor and shook Rose's. 'You can tell you're getting older. Your assistants are getting younger.'

'I'm not their assistant!'

'No? Get you, tiger.'

The Wizard snorted as The Doctor rubbed the back of his head, gestured forward and left them behind. They made to follow but The Wizard, still holding Sarah's hand, grabbed Rose's.

'Right. I hate it when this happens. Rose, Sarah Jane is a very old and very close friend of ours, she travelled with us in the days before the Time War. And no, you're not our assistant, you're a companion. Sometimes people call you assistants. Sarah, this is Rose, our companion. She's completely brilliant. Sarah is an investigative journalist and Rose… well… she was employed, but then The Doctor and I blew up where she worked. Long story. Please don't fight, you're both lovely and fantastic and a no worse companion the other.'

They nodded at each other and shook hands again, this time lighter hearted. Then The Wizard took Rose's hand with her other and they ran after The Doctor, all grinning. They caught up just as he found the source of the noise. Mickey, surrounded by small bags.

'Sorry! Sorry, it was only me. You told me to investigate, so I started looking through some of these cupboards and all of these fell on me.'

The Doctor and The Wizard bent down to pick one up.

'Oh, my God, they're rats,' said Rose. 'Dozens of rats. Vacuum packed rats.'

'And you decided to scream,' said The Doctor, standing up again and looking at Mickey.

'It took me by surprise!'

'Like a little girl?'

'It was dark! I was covered in rats!'

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

'Pink,' added The Wizard.

'Hello, can we focus?' Rose said. 'Does anyone notice anything strange about this? Rats in school?'

'Well, perhaps they use them in Biology lessons to dissect them,' said Sarah.

'Not many schools dissect rats anymore,' replied Rose, motioning for The Wizard to pass her one, 'but I can't see what else they'd be used for.'

'Everything started when Mister Finch arrived,' said The Doctor in thought. 'We should go and check his office.'

'Good idea,' said Rose and Sarah. They smiled at each other and The Wizard was happy.

'Maybe those rats were food,' said The Doctor as they reached the office. He pointed his sonic screwdriver at the lock.

'Food for what?' asked Rose from behind The Wizard.

'Rose, you know you used to think all the teachers slept in the school?' said The Doctor as he and The Wizard stepped in so the others could look, 'Well, they do.'

Hanging upside down were large, bat-like creatures. Mickey took one look at them and ran;

'No way!'

Rose and Sarah dashed after him and The Doctor and The Wizard quietly closed the door. They caught up with the others outside.

'I am not going back in there. No way.'

'Those were teachers,' panted Rose.

'When Finch arrived, he brought with him seven new teachers, four dinner ladies and a nurse. Thirteen. Thirteen big bat people. Come on.' The Doctor, unfazed, turned to go back inside.

'Come on? You've got to be kidding!' Mickey stayed put as the others moved.

'We need the Tardis. We've got to analyse that oil from the kitchen.'

'I might be able to help you there. I've got something to show you.' Beaming, Sarah took their arms and led them to her car.

The second the door opened The Wizard took off the blanket from the thing in Sarah's boot. She and The Doctor beamed.

'K9!' they chorused.

'Rose Tyler, Mickey Smith, allow me to introduce K9. Well, K9 Mark Three to be precise.' The Doctor watched The Wizard as she fiddled with some wires, already looking at repairs.

'Why does he look so disco?' asked Rose.

'Oi!' said The Doctor as he, The Wizard and Sarah glared at Rose, 'Listen, in the year five thousand, this was cutting edge. What's happened to him?'

'Oh, one day, he just, nothing.' Sarah shrugged.

'Well, didn't you try and get him repaired?' The Doctor asked, whining.

The Wizard tutted.

'Well, it's not like getting parts for a Mini Metro, besides, the technology inside him could rewrite human science. I couldn't show him to anyone!'

'Ooh,' cooed The Doctor, 'what's the nasty lady done to you, eh?' He rubbed K9's ears.

'What's she done?' The Wizard joined in.

Mickey raised an eyebrow.

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

The Wizard shot Rose an annoyed look and with reluctance she and The Doctor shut the boot.

They went to a coffee shop and immediately The Wizard and The Doctor started working on K9. Rose and Mickey went to order and Sarah sat with the Timelords.

Happily they worked, laughing.

'I thought of you on Christmas Day. This Christmas just gone? Great big spaceship overhead. I thought, oh yeah, bet he's up there.'

'Right on top of it, yeah.'

'He'd just regenerated.'

'And you, Wizard?'

'I was there, too. He lost his hand and grew another.'

Sarah laughed. A moment later she became quiet again. 'Did I do something wrong, because you never came back for me. You just dumped me.'

The Doctor stopped working and The Wizard put down her tea.

'We told you. We were called back home and in those days humans weren't allowed.'

'I waited for you. I missed you.'

'Oh, you didn't need us! You were getting on with your life.'

The Wizard sighed.

'You were my life. You know what the most difficult thing was? 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 asked, confused.

'No!, but we get a taste of that splendour and then we have to go back.'

'Look at you, you're investigating!' The Doctor smiled, 'You found that school. You're doing what we always did.'

'You could have come back.'

The Doctor stopped smiling and The Wizard's eyes went grey. Sarah noticed. 'We couldn't.'

'Why not?'

The Doctor turned his sonic back on and continued working on K9. The Wizard sighed and picked up her tea again.

'You deserve to know, Sarah,' she sighed. 'It got a bit hectic when we went back to Gallifrey. People that travel with us, they fade. We didn't want your life to be used up on us, when you had so much to do.'

Sarah nods. 'It wasn't Croydon. Where you dropped me off, that wasn't Croydon.'

'Where was it?' asked The Doctor.

'Aberdeen.'

'I told you!' exclaimed The Wizard, 'I bloody told you so!'

'Right. That's next to Croydon, isn't it?'

'Ugh.' The Wizard laughed and let her head fall to the table.

K9 whirred and his eyes lit up. The Doctor and The Wizard leapt to their feet.

'Oh, hey. Now we're in business.'

'Master. Mistress.'

'He recognises us!'

'Affirmative.'

The Wizard cooed and patted him.

'Rose, give us the oil.'

Rose passed The Doctor the oil in a small container. 'I wouldn't touch it, though. That dinner lady got all scorched.'

'I'm no dinner lady. And I don't often say that.'

The Wizard laughed as The Doctor put the oil onto K9's probe.

'Here we go. Come on, boy. Here we go.'

'Oil. Ex ex ex extract. Ana ana analysing.'

'Listen to him, man. That's a voice.' Mickey was laughing.

The Wizard elbowed him and Sarah and The Doctor glared.

'Careful. That's my dog.'

'Confirmation of analysis. Substance is Krillitane Oil.'

'Ah,' said The Wizard.

'They're Krillitanes.'

'Is that bad?' Rose asked.

'Very. Think of how bad things could possibly be, and add another suitcase full of bad.'

'And what are Krillitanes?' Sarah asked.

'They're a composite race. 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. 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.'

'Like Kaminoans from Star Wars,' The Wizard said.

'What're they doing here?' Rose asked, nervous.

'It's the children. They're doing something to the children.'

'We need to come up with a plan. Let's get K9 back into the car and we can think things through,' said The Wizard.

'Good idea.' The Doctor picked up K9 and passed him to The Wizard and they walked out. Sarah took K9 from The Wizard after she'd opened the boot and The Wizard went back to The Doctor.

Rose was rounding on him. 'How many of us have there been travelling with you?'

'Does it matter?' The Doctor looked uneasy.

'Yeah, it does, if I'm just the latest in a long line.'

'As opposed to what?'

'We're over 900 years old, did you expect to be the first?' The Wizard asked.

Rose stopped and looked at The Doctor. 'I thought you and me were. I obviously got it wrong.' She looked at both of them. 'I've been to the year five billion, right, but this? Now this is really seeing the future. You just leave us behind. Is that what you're going to do to me?'

'No. Not to you.'

'Rose, we never leave people behind if we can help it.'

'But Sarah Jane? You were that close to her once, and now you never even mention her. Why not?'

'We don't age. We regenerate. But humans decay. You wither and you die. Imagine watching that happen to someone who you…'

'What, Doctor?'

The Wizard spoke. 'We travel with you, Rose, all of you. We watch as you grow older little by little until finally we have to leave you behind. The Doctor's right. You wither and die. Imagine it from our point of view.'

The Doctor drew in breath. 'You can spend the rest of your life with us, but we can't spend the rest of ours with you. We have to live on. Alone. That's the curse of the Time Lords.'

'Because there's none left.' The Wizard's eyes were grey again.

Suddenly a Krillitane swooped down over them. The Doctor and The Wizard pulled the other three down. It flew over Sarah and The Wizard put herself over her.

'Was that a Krilliatane?'

'Yes.' The Wizard stood up.

'But it didn't even touch her. It just flew off. What did it do that for?' Rose breathed.

'We'll find out soon enough.'

The next morning they got out of the car at the school and The Doctor said the plan.

'Rose and Sarah, you go to the Maths room. Crack open those computers, I need to see the hardware inside. Here, you might need this.' He passed his screwdriver to the closest of the two; Sarah. 'Mickey, surveillance. I want you outside.'

'Just stand outside?' He stopped walking.

Sarah turned back. 'Here, take these you can keep K9 company.' She threw him her car keys.

'Don't forget to leave the window open a crack!' calls The Doctor.

'But he's metal!'

'I didn't mean for him,' The Doctor replies, like Mickey's thick.

'What're you going to do?' Rose asks The Timelords.

'It's time we had a word with Mister Finch.'

They found him at the swimming pool and stood at opposite ends.

'Who are you?' asked The Doctor.

'My name is Brother Lassa. And you?'

'The Doctor, this is The Wizard. Since when did Krillitanes have wings?'

'It's been our form for nearly ten generations now. Our ancestors invaded Bessan. The people there had some rather lovely wings. They made a million widows in one day. Just imagine.'

'And now you're shaped human.'

'A personal favourite, that's all.'

'Can't imagine why,' said The Wizard. The Doctor nearly laughed.

'And the others?'

'My brothers remain bat form. What you see is a simple morphic illusion. Scratch the surface and the true Krillitane lies beneath. And what of the Time Lords? I always thought of you as such a pompous race.' They began walking to the end of the pool.

The Wizard's eyes narrowed.

'Ancient, dusty senators, so frightened of change and chaos.'

Her teeth gritted.

'And of course, they're all but extinct. Only you. The last.'

'This plan of yours,' said The Doctor, 'What is it?'

'Do tell,' The Wizard said, slightly menacingly.

'You don't know.'

'That's why we're asking,' The Doctor said plainly.

'Well, show me how clever you are. Work it out.' They stopped a few metres from each other.

'If we don't like it, then it will stop.'

'Fascinating. Your people were peaceful to the point of indolence.'

'We were changed,' said The Wizard bluntly.

'Would you declare war on us, Doctor, Wizard?'

'We're so old now. We used to have so much mercy. You get one warning. That was it.' The Doctor turned and started walking. The Wizard stayed.

'But we're not even enemies. Soon you will embrace us.' The Doctor stopped and turned to frown at Finch. 'The next time we meet, you will join with me.'

The Wizard raised her eyebrows and walked away.

'I promise you.'

'It's not working,' Sarah sighed.

'Give it to me. The Doctor changed it a bit the other week, it's being silly.' Rose hit the sonic onto her palm.

'Is The Wizard's still pristine and perfect?' asked Sarah.

'Yeah,' Rose laughed, 'I've always wondered, but never asked, what are all those circles on the casing? Do you know? It looks like her bracelet.'

'Oh, that's not a bracelet,' explained Sarah, 'it's a watch. It's the Timelord circular alphabet. The watch changes as time moves.'

'Do you know what the writing on her sonic says?'

'She told me once, it says "Gallifrey." She said it was a reminder to always visit home.'

Rose looked down. 'The Wizard can seem very distant sometimes.'

'Her eyes go grey,' Sarah said, 'they lose all the blue.'

'It happens sometimes,' Rose said, finally getting The Doctor's sonic working, 'she always looks sad when it does.' Rose paused. 'What was she like when you travelled with her?'

'Well, she had short bright orange hair and loved coffee.'

'She hates coffee now!' Rose laughed, 'she says she's hated it for her last two regenerations.'

Sarah laughed as well. 'Tell me what you've seen, Rose, there's always so much out there.'

Rose stood up as the computer whirred. 'You first.'

'Mummies.'

Rose raised her eyebrow, impressed. 'Ghosts.'

'Robots. Lots of robots. Those two are obsessed with robots!'

Rose laughed. 'Slitheen, in Downing Street.'

'Sounds fun. Daleks!'

'You too? I met the Emperor.'

'You should have seen their creator! Oh, a favorite of mine, Anti-matter monsters.'

'Gas masked zombies.'

'Really?'

'World War II,' Rose explained.

'Ahh. Oh, real living dinosaurs.'

'Real living werewolf.'

'The Loch Ness Monster!'

'Seriously?'

Sarah nodded.

Rose looked down for a moment. 'With you, did they do that thing where they'd explain something at like, ninety miles per hour, and you'd go, "what?" and they'd look at you like you'd just dribbled on your shirt?'

'All the time! Their brains are incredible and you feel so small.' Sarah laughed. 'The Tardis is sentient, I know, but does The Doctor still stroke bits?'

'Yeah! Yeah, he does. I'm like, do you two want to be alone? And Wizard, half the time I can't tell if she's talking to me or the Tardis when it's just us in there.'

They laugh again.

'How's it going?' asked The Doctor, as he and The Wizard entered the room.

The two saw him and The Wizard and laughed.

'What? Listen, I need to find out what's programmed inside these-,'

Rose pointed at him and they laughed harder.

'What?'

They reached hysteria and The Doctor looked like a small child. 'Stop it!'

A minute later they'd quietened down and The Doctor had his sonic back. He and The Wizard were fiddling with a computer. 'I can't shift it.'

'I thought the sonic screwdriver could open anything!' Sarah exclaimed, worried.

'Anything except a deadlock seal. There's got to be something inside here. What're they teaching those kids!?'

Suddenly the screens lit up with green and flashed in alien symbols.

'You wanted the programme? There it is.'

'Some sort of code.' The Doctor looked at it.

'Oh. No, no, no, no, no, no, no…'

The Doctor turned to The Wizard. 'What is it?'

'The Skasis Paradigm.'

'No, no, it can't be.'

'It is.'

'They're trying to crack the Skasis Paradigm?!'

'The Skasis what?' Sarah looked between the two as they stood there in horror.

'The God maker,' said The Wizard.

'The universal theory. Crack that equation and you've got control of the building blocks of the universe. Time and space and matter, yours to control.'

'What, and the kids are like a giant computer?' Rose asked, looking alarmed at how rigid the two had become.

'Yes. And their learning power is being accelerated by the oil.' The Doctor paced around another row of computers. 'That oil from the kitchens, it works as a, as a conducting agent. Makes the kids cleverer.'

'But that oil's on the chips. I've been eating them,' Rose said.

'What's fifty nine times thirty five?'

'Two thousand and sixty five.'

The Doctor and The Wizard gave a "there you are," look.

'Oh, my God.'

'But why use children?' Sarah asked. 'Can't they use adults?'

'No, it's got to be children. The God maker needs imagination to crack it. They're not just using the children's brains to break the code, they're using their souls.'

'Let the lesson begin.'

The Wizard and The Doctor turned to see Finch standing in the doorway. 'Think of it, Doctor, Wizard. With the Paradigm solved, reality becomes clay in our hands. We can shape the universe and improve it.'

'Oh yeah? The whole of creation with the face of Mister Finch? Call me old fashioned, but I like things as they are.'

'Definitely,' agreed The Wizard.

'You act like such radicals, and yet all you want to do is preserve the old order? Think of the changes that could be made if this power was used for good!'

'What, by someone like you?'

'No, someone like you. The Paradigm gives us power, but you could give us wisdom. Become Gods at my side. Imagine what you could do. Think of the civilisations you could save. Perganon, Assinta. Your own people, Wizard, Doctor, standing tall. The Time Lords reborn.'

'See that's your mistake,' The Wizard said, 'we're not anything different from them. We do the right thing, we live by our codes. The universe is to be observed and admired, not to be changed! That's what we fought the Time War for.'

To add to the scene, The Doctor threw a chair at the large screen upfront. 'Out!'

'Out, Sarah! Rose!'

They ran from the classroom and into Mickey in the hall. A young boy was with him.

'What is going on?' Mickey asks.

'Run!' The Wizard shouted and they ran from the oncoming Krillitanes into the cafeteria.

'Are they my teachers?' asked the boy.

'Yeah. Sorry,' said The Doctor.

'Great story for the first day of your next ones,' added The Wizard with a wink as she pulled Sarah behind her.

'We need The Doctor and The Wizard alive. As for the others? You can feast.'

'No you won't.' From inside her bigger on the inside jacket pockets, The Wizard brought out her Gallifreyan sword. 'K9!'

'Affirmative, mistress.' He fired and hit one.

'K9!' shouted Sarah Jane as The Wizard protected her from a swoop.

'Suggest you engage running mode, mistress.'

'Good suggestion,' said The Wizard.

'Come on!' yelled The Doctor, as Finch roared in fury. 'K9, hold them back!'

'Affirmative, master. Maximum defence mode.'

The Doctor sealed the door with a wave of his sonic and The Wizard was already fiddling with a marker in the physics classroom. Rose understood finally what she was doing when she drew circles in circles; calculations.

'It's the oil.' The Doctor said. 'Krillitane life forms can't handle the oil. That's it! They've changed their physiology so often, even their own oil is toxic to them. How much was there in the kitchens?'

'Barrels of it.'

'Define barrels,' said The Wizard.

'At least five.'

She drew one more circle onto the whiteboard. 'Easily enough.'

The Doctor glanced at the board. 'What did you do that on the board for?' he asked in confusion.

She shrugged, getting ready to open the door as the Krillitanes banged on the other side. 'I needed to fiddle with something.' She ran out of the way of the board before The Doctor could realise what she'd written completely. Only a tiny portion of it was about oil. The rest were time calclations.

'No… what? Wizard…? What are you doing?'

'Don't worry, I'll be fine.'

'As long as you say so. Okay, we need to get to the kitchens. Mickey.'

'What now, hold the coats?'

'Get all the children unplugged and out of the school. Now then, bats, bats, bats. How do we fight bats?'

The fire alarm went off behind them and The Wizard and The Doctor realised the boy had done it.

'Nice work,' congratulated The Wizard. She opened the door. 'Everybody out!'

They ducked and ran underneath the cowering Krillitanes as they recovered from the noise.

When they're away the noise stopped and were outside the canteen when K9 reached them.

'Master.'

'Come on, boy. Good boy.' The Doctor scratched his ears.

Mickey split up from them and they were in the kitchen looking round when The Wizard pulled out her sonic and her Tardis key, not that anyone noticed.

The Doctor used his own sonic on the barrels, but they didn't open. 'They've been deadlock sealed. Finch must've done that. I can't open them.'

'The vats would not withstand a direct hit from my laser, but my batteries are failing,' said K9.

'Right. Everyone out the back door. K9, stay with us.'

The Doctor and The Wizard pulled the barrels around so that K9 could easily shoot them from where he was by the door.

'Capacity for only one shot, Master, Mistress. For maximum impact, I must be stationed directly beside the vat.'

'But you'll be trapped inside.' The Doctor gasps.

'That is correct.'

'I can't let you do that.'

'No alternative possible, Master.'

'Goodbye, old friend.'

'Goodbye, Master. Mistress.'

'You good dog.'

'Affirmative.'

They run out and The Doctor seals the door. Sarah runs to him.

'Where's K9?'

'We need to run.'

'Where is he? What have you done!'

The Doctor looked back and stopped. 'Wizard…'

The Wizard had been right behind him when he ran out of the café.

'She must have gone the other way.' He made to run back in, but this time Sarah held him back. 'No, Doctor. She knows what she's doing.'

The Tardis landed and The Wizard set the destination for the next jump, though she pointed the sonic at the doors to open to stop it from taking off.

'You bad dog.'

'Affirmative.'

That's what The Wizard heard when she opened the Tardis doors, right behind K9. 'K9, get in!'

'Coming, Mistress!'

The second was inside The Wizard shut the door and the Tardis whirred. The Wizard picked up K9 and walked outside. It was the year 1998 in a random park. This would do. She shut the doors and took K9 down into the machine lab in the Tardis.

The Tardis whirred behind the kids, so The Doctor and Sarah didn't hear it.

'I'm sorry.'

'It's all right. He was just a daft metal dog. It's fine, really.'

The Doctor hugged Sarah, but turned his head when he heard boots he recognised.

'Sarah,' came The Wizard's voice.

Sarah looked up from The Doctor's shoulder and gasped. Shiny and spotless, complete circuits was K9.

'Is it my K9?'

The Wizard nodded and held him out.

'You cleaned him up! And he's completely repaired!' Sarah passed K9 to The Doctor and hugged The Wizard. 'Thank you!'

The Doctor grinned. 'I didn't think there was enough time to get to the Tardis to do that,' he said.

'Clearly didn't check my calculations, then,' she replied.

The Wizard landed the Tardis as The Doctor, Mickey and Sarah Jane reached it. They took Sarah's car. K9 and The Wizard stuck their heads out of the doors. The Doctor smiled; The Wizard, against the blue and green background of the garden and Tardis looked very happy. He loved it when she was.

'Cup of tea?'

'Good idea,' said The Wizard and darted back inside. 'Rose, grab cups.'

Mickey went in ahead of The Doctor and Sarah Jane. Rose, who'd went with The Wizard, passed him a cup as The Wizard disappeared down the stairs. She came up again when Sarah came in, carrying a tray.

As she entered, Sarah looked around.

'You've redecorated.'

'Do you like it?' asked The Doctor and The Wizard in unison.

'Oh, I, I do. Yeah. I preferred it as it was, but er, yeah. It'll do.'

'I love it,' Rose grinned.

'Hey, you! What's… forty seven times three hundred and sixty nine?' Sarah asked Rose.

'No idea. It's gone now. The oil's faded.'

'17,343,' said The Wizard, pouring tea.

'Show off.'

'Can't help it if I'm a Timelord,' she shrugged.

Sarah laughed and turned to Rose again. 'But you're still clever. More than a match for him.'

'You and me both. Doctor? Wizard?'

'Um, we're about to head off, but… you could come with us.' The Doctor offered.

Sarah could tell The Wizard knew her answer. She took a cup of tea from the tray. 'No. I can't do this anymore. Besides, I've got a much bigger adventure ahead! Time I stopped waiting for you and found a life of my own.'

The Wizard nodded and gave Sarah Jane a hug. Mickey spoke up a moment later, making Rose's face freeze.

'Can I come?'

Sarah frowned.

'No, not with you, I mean with you. Because I'm not the tin dog, and I want to see what's out there.'

The Wizard blinked in surprise. 'What happened to it being crazy in here, and scary?' she asked.

Mickey chuckled as Rose mouthed, "No," at The Doctor and The Wizard.

'Oh, go on, Doctor. Sarah Jane Smith, a Mickey Smith. You need a Smith on board,' smiled Sarah.

'We certainly do,' said The Wizard, grinning down at Sarah.

'Okay then, I could do with a laugh.'

'Rose, is that okay?' Mickey asked.

Rose was looking down. 'No, great. Why not?'

'Well, I'd better go.' Sarah finished her tea and The Wizard took the cup from her.

Sarah took Rose aside and Rose was panicking. 'What do I do? Do I stay with them?'

'Yes. Some things are worth getting your heart broken for.' Sarah hugged her. 'Find me, if you need to, one day. Find me.'

The Timelords, meanwhile, were reassuring Mickey, The Doctor by being his normal self and teasing him, The Wizard showing him the basic things he'd need to know.

'That,' she said, pointing at a small lever on the console, 'is the light switch. This here,' she pointed to a singular button third from the left on a row, 'is the button you press when you have questions and can't find us, if we're in or out of the Tardis, we'll get the message. Now, don't feel stupid not knowing where anything is, we're used to it. So anything you need help with, you press that button. Last one up here at night is usually The Doctor or I as we sleep less than you do, but if it's you, you turn off the lights.'

Mickey nodded. 'Hey, thanks for letting me come.'

'Not at all,' grinned The Doctor, 'it'll be fun!'

The Wizard glanced behind her as she was unexpectedly pulled into a hug. She took Sarah to the door, The Doctor following them out.

'It's daft, but I haven't ever thanked you for that time. And like I said, I wouldn't have missed it for the world.'

The Wizard leant on the Tardis as K9 came out of the doors. She knelt by him and scratched his ears.

'Something to tell the grandkids,' smiled The Doctor.

'Oh, I think it'll be someone else's grandkids now.'

'Right. Yes, sorry. I didn't get a chance to ask. You haven't…? There hasn't been anyone? You know.'

'Well, there was this one guy. I travelled with him for a while, but he was a tough act to follow. Goodbye, Doctor.'

'Oh, it's not goodbye.'

'Do say it. Please. This time. Say it.'

'Goodbye, my Sarah Jane.'

The Doctor pulled her into a hug and lifted her off of her feet. When he put her down, The Wizard stood up and he began talking to K9.

'I hate saying goodbye to you,' laughed The Wizard, tears in her eyes.

'Thank you for always saying it,' Sarah replied.

'I'll pop in for tea sometimes,' The Wizard said. She pointed over her shoulder at The Doctor. 'Unlike him I do house calls.'

Sarah's smile lit up. 'Would you?'

'Of course. I can't promise an exact time, but I promise I will.'

'I wasn't sure when you promised me all those years ago that you'd come back,' Sarah said, 'but I know you're going to keep this one.'

The Wizard let a tear fall from her eye. 'You're one of the best, Sarah Jane.'

'If you're crying then you'd better call in on me soon.'

The Wizard laughed. 'Yeah, within a month judging by this,' she gestured to her face and pulled Sarah into a hug, lifting her up like The Doctor had done.

They smiled at her and went back inside the Tardis, winking at K9.

'Oh my goodness, you're actually crying,' said The Doctor.

'Shut up,' laughed The Wizard.

The Doctor laughed and wiped a tear from The Wizard's face, hugging her.

'Ugh, stupid,' she said and squeezed him and let go. 'Right. I'm going to need some tea-,'

Everyone laughed.

'-then we can go on Mickey's first adventure.'