The Jeep came to a hault in the middle of a junction as Donna jumped out. "I'll walk the rest of the way." She reassured the Time Lords. "I'll see you two back at the factory, yeah?"

"Bye!" They both waved at her as she moved away.

"And you be careful!" She shouted pointing at the Doctor before the jeep pulled away.

"Why did she only warn me?" The Doctor looked at Rita.

"Sweetheart you and trouble go together like bread and butter."

"What does that make you and trouble then?" He raised a brow at her.

"Bread and butter." She smirked and looked out of the window then frowned slightly. "I forgot to ask, where are we even going?"

"A 'child genius' invented ATMOS." He explained at Rita who raised a brow interested from the moment he said 'genius' and 'invented'. "He apparently runs a private school for selected students, thought we could take a trip there, I know you would want to see what they have been getting up to." He grinned at her.

"Are you just getting lonely that I'm the only other genius apart from you?" She raises a brow at him.

"Possibly." He smirked glancing away from the blonde as she shook her head disapprovingly at him.

They continued driving in silence until Ross started to explain to them about Rattigan, "UNIT's been watching Rattigan Academy for ages. It's all a bit Hitler Youth. Exercise at dawn and classes and special diets."

"Turn left." The ATMOS device instructed.

"Ross," the Doctor frowned slightly, "one question. If UNIT think that ATMOS is dodgy..."

"Go straight on."

"How come we've got it in the jeeps?" Ross finished. "Yeah, tell me about it. They're fitted as standard on all government vehicles. We can't get rid of them till we can prove there's something wrong."

"Turn right."

"Drives me around the bend." He commented as the car turned following the road.

"That was clever, good joke." Rita spoke up from the back.

"Timed that perfectly." Ross chuckled.

"Yeah." The Doctor nodded. "Yeah, you did."

"This is you final destination." The ATMOS device shortly informed them, Ross then stopped the jeep, the Doctor stepped out opening Rita's door for her even though she could open it perfectly find on her own, rolling her eyes he smirked at her, they walked up the gravel path and watched the students in a sort of uniform run around as they walked up to Rattigan.

"Is it PE?" The Do tor joked. "I wouldn't mind a kick around, I've got me daps on."

"Sandshoes." Rita coughed jokingly.

"I suppose you're the Doctor and the Stone?" The boy turned around.

"Hello." The Doctor grinned.

"That's us." Rita waved.

"Your commanding officer phoned ahead."

"Ah, but we haven't got a commanding officer." The Doctor stepped forward. "Have you?" He asked, the boy glared at him. "Someone doesn't like you." Rita muttered to him. "I think he's worried of getting out smarted."

"I'm just wanting until you start opening your mouth." The Doctor grinned at her then looking at Ross. "Oh, this is Ross. Say hello, Ross."

"Good afternoon, sir." Ross nodded at the boy.

"Let's have a look, then." The Doctor took Rita's hand practically bouncing into the Academy. "I can smell genius!" He then muttered over his shoulder. "In a good way."

They entered the Academy laboratory, Rita broadly smiled looking around at the different equipment and devices. "Oh, now, that's clever." She muttered glamcimg around hands in her trouser pockets observing the young humans fiddle with equipment. "Ah ha!" She beamed moving over. "Look Doctor, single molecule fabric." The Doctor placed his glasses on watching the giddy blonde.

"How thin is that?!" He asked amazed. "You could pack a tent in a thimble. Ooo!" He moved over pulling her alone with hi,. "Gravity simulators."

"Terraforming, biospheres, nano-tech steel construction." She moved around the room. "I'm very impressed." She nodded. "Extremely impressed well done." She nodded.

"This is brilliant." The Doctor looked around extatic. "Do you know, with equipment like this you could, ooo, I don't know," he shrugged, "move to another planet or something?"

"If only that was possible." Rattigan looked at them both annoyed.

"Ah that would be were, if only that were possible." She shrugged it off. "Conditional clause, easy mistake for some."

Rattigan looked as if he was boiling at them both sending a glare and narrowing his eyes. "You did that on purpose." The Doctor stated.

"I could see he hated us from the moment we turned up, wanted to see how far I could push him, plus it's fun to almost have an ego as big as yours sometimes."

"I think you'd better come with me." Rattigan growled turning around and storming off.

"See?" She raised her eyebrows at the Doctor proving her point and following the boy with the Doctor, Ross followed behind them.

They entered a large room with a swimming pool at the back of the room and a transmat in the corner.

"You're smarter than the usual UNIT grunts," Rattigan eyed Ross after a comment he made. "I'll give you that."

"He called you a grunt." The Doctor looked at Ross. "Don't call Ross a grunt." He told Rattigan. "He's nice. We like Ross." He nodded. "Look at this place."

"What exactly do you want?" He hissed at the Doctor.

"I was just thinking, well,." He nodded at Rita, "we were just thinking. What a responsible eighteen year old. Inventing zero carbon cars? Saving the world."

"Takes a man with vision." Rattigan told them.

"Mmm, blinkered vision." The Doctor hummed. "Because ATMOS means more people driving. More cars, more petrol. End result, the oil's going to run out faster than ever."

"The ATMOS system could make things worse." Rita added.

"Yeah." He snapped at the blonde. "Well, you see, that's a tautology. You can't say ATMOS system because it stands for Atmospheric Emissions System. So you're just saying Atmospheric Emissions System system." He glared at her. "Do you see, Miss Conditional Clause?"

The Doctor looked at the boy for a moment his face as well as Rita's becoming slightly soft. "It's been a long time since anyone said no to you, isn't it?"

"I'm still right, though." He protested.

"Not easy, is it, being clever." The Doctor stepped forward. "You look at the world and you connect things, random things, and think, why can't anyone else see it? The rest of the world is so slow."

"Yeah." He sighed.

"And you're all on your own."

"I know."

"But." Rota dragged it out walking over to the transmat. "I can't help thinking that your just a boy, not to be offensive or anything." She raised her hands up. "There is no way you invented that all on your own." She pointed at the device the Do tor brought out and tosses it to Ross. "Trust me I used to invent quiet a lot back home, I would know."

"It might be Earth technology, but that's like finding a mobile phone in the Middle Ages." The Doctor cut in then shook his head. "No, no, I'll tell you what it's like. It's like finding this in the middle of someone's front room." He stepped over to it Rita following. "Albeit it's a very big front room."

"Why, what is it?" Ross frownee not understand the two."

"Yeah, just looks like a thing, doesn't it?" The Doctor laughed a little pointing at the machine. "People don't question things. They just say, oh, it's a thing."

"Leave it alone." Rattigan hissed at them.

The Doctor amd Rota stepped into the machine.

"The Stome and I, we make these connections." He said taking her hand. "And this, to me, looks like a teleport pod." He pushed the button then vanished appearing again on a ship with figures half her size walking about.

"Orbit now holding at five five six point three, sector two seven zero." A computer stated.

"Oh." The Doctor frowned and worryingly took the blondes hand.

"Not good." Rita muttered as they all turned and looked at the Doctor and Rota.

"We have intruders!" One of the pointed to the two.

"How did they get in?" The Doctor questioned, "in tru da window? Bye, bye!" He hit the button and ran taking Rita with him.

"Ross, get out!" The Doctor shouted. "Luke, you've got to come with us." He tried pulling the boy back who then refused. Rita flashed her sonic at the teleport a moment too late as a Sontaran appeared.

"Sontaran!" The Doctor shouted. "That's your name, isn't it?" He asked "You're a Sontaran. How did I know that, hey? Fascinating isn't it? Isn't that worth keeping me alive?"

"I order you to surrender in the name of the Unified Intelligence Taskforce." Ross held a gun up at it."

"Sorry Ross but that's useless." Rita informed him moving slightly away from the gun herself. "Cordolanie signal which is copper excitation stopping the bullets makes them sort of expand so they don't look like bullets anymore."

"How do you know so much?"

"Well." The Doctor shrugged.

"Who is he?" The Sontaran questioned Rattigan

"He didn't give his name. Nor did she."

"But this isn't typical Sontaran behaviour, is it?" The Doctor questioned. "Hiding? Using teenagers, stopping bullets? A Sontaran should face bullets with dignity. Shame on you."

"You dishonour me, sir."

"Yeah? Then show yourself."

"I will look into my enemy's eyes!" He stated then removed his helmet to show what looked like a light brownish head resembling something that humans most likely thought looked like a potato.

Ross' eyes widened. "Oh, my God."

"And your name?"

"General Staal, of the Tenth Sontaran Fleet." He announced with pride. "Staal the Undefeated."

"What would happen if you get defeated? That's quiet a rubbish nickname." Rita crossed her arms. "Staal the Not Quite So Undefeated Anymore But Never Mind?" The Doctor remarked making Ross snort a laugh before becoming serious once more.

"He's like a potato." Ross eyed Staal. "A baked potato. A talking baked potato."

"Now, Ross, don't be rude." He Doctor scolded. "You look like a pink weasel to him."

"And you look like a piece of string." Rita snorted a laugh as the Doctor scolded her with a glare, she then handed him a racket. "Fancy a bit of tennis sweetheart?" Nodding he took the racket while she tossed a ball in the air a couple of times while the Doctor spoke.

"The Sontarans are the finest soldiers in the galaxy, dedicated to a life of warfare. A clone race, grown in batches of millions with only one weakness."

"Sontarans have no weakness." Staal stated.

"Everyone has a weakness." Rita scoffed.

"It's s a good weakness." The Doctor added.

"Aren't you meant to be clever?" Rattigan spat. "Only an idiot would provoke him."

"Yeah but he can be a right idiot at times."

"but the Sontarans are fed by a probic vent in the back of their neck." He explained ignoring the Time Ladys remark, lightly hitting the back of his own neck with the racket. "That's their weak spot. Which means, they always have to face their enemies in battle. Isn't that brilliant?" He beamed. "They can never turn their backs."

"We stare into the face of death." Staal protested.

"Yeah? Well, stare at this." Rita tossed the ball into the air, the Doctor smashed it in the back of the teleport, the ball bounced off the back hitting Staal on the probic vent.

Staal cried out slumping to his kneels. The Doctor grabbed Rita's hand and pushed Ross towards the exit. "Run!"

"What has you done?" Rattigan shouted as the three sprinted away. They jumped into the jeep the Doctor in the front with Ross, Rita in the back.

"Greyhound Forty to Trap One." The Doctor said into a walkie talkie as Ross sped off away from Rattigan's academy. "Repeat, can you hear me? Over."

"Why's it not working?" Ross frowned.

"It must be the Sontarans. If they can trace that, they can isolate the ATMOS." The Doctor explained.

"Turn left." The ATMOS device informed.

The Doctor spoke up. "Try going right."

"It said left."

"He knows, go right." Rita backed the Doctor up Ross attempt to turn the wheel right, locking itself the car turned by itself Ross moved his hands away looking slightly terrified. "I've got no control. It's driving itself. It won't stop." The Doctor flashed his sonic at the ATMOS device. "The doors are locked." Ross said trying to open one of them.

"Deadlocked." Rita grumped trying to open the door. "One of these days I am going to change that... hopefully."

"If we even get out of this car." Ross muttered.

"Have some hope Ross." The Doctor said over his shoulder trying to break open the door.

"Turn left."

"The sat-nav's just a box, wired through the whole car." The Doctor said still trying to open his door

The car turned a corner, the three saw a large river in front. Ross swallowed. "We're headed for the river."

"Okay nos it's my turn." Rita unbuckled her seat belt and leant between the two seats. "ATMOS I'm guessing that you are programmed to completely ignore and contradict my orders?"

"Confirmed."

"So anything I ask you will completely ignore?"

"Confirmed."

"Right then thank you now drive us right into that river." She said the Doctor looking at her understanding her plan taking her hand in his. "ATMOS I order you to drive into the river!" She shouted. "Completely ignore me and drive into the river!" She shouted again as the car came to a stop on the edge of the river.

The Doctor jumped out the car with Rita and Ross, taking her hand they ran in the opposite direction to the river while the ATMOS device started to smoke confusing itself.

"Get down!" The Doctor shouted pulling Rita down to the ground covering his hands over his head beside the blonde.

"Left, right, left, right..." the ATMOS device said, "left, left, right, left, right..." it then gave out a small spark and a bang. The Doctor frowned looking up. "Oh, was that it?" He looked slightly disappeared.

"Better that then being at the bottom of a river." Rita muttered standing up and brushing herself off.

The Doctor, Rita and Ross walked down Donna's street seeing her outside looking at her car.

"You would not believe the day we're having." He said walking up to Donna.

"With Donna knowing the days we can have she might just believe us." Rita commented following him. He knelt down and looked at the ATMOS device stuck to the bottom of the car.

"I'll requisition us a vehicle." Ross then began to walk off down the street. The Doctor stood up and pointed at him.

"Anything without ATMOS. And don't point your gun at people."

He nodded then left as the old man Rita remembered from Christmas Eve walked of out Donna's house.

"Is it them?" He asked walking over to Donna seeing the Doctor looking under the car. "Is it them? Is it the Doctor and the Stone?" He asked. The Doctor looked up frowning when the man saw him. "Ah, it's you!"

"Who?" He looked up. "Oh, it's you two."

"What?" Donn looked between the three confused, "you met before?"

"Yeah, Christmas Eve. He and the Stone disappeared right in front of me."

"And you never said?" Donna looked over at her grandad while Rita scratched the back of her neck.

"Well, you never said." He shrugged. "Wilf, sir. Wilfred Mott. You must be one of them aliens."

"Yeah, but don't shout it out." The Doctor told him shaking his hand. "Nice to meet you properly, Wilf."

"Oh, an alien hand." Rita chuckled at the man.

"Oh my god." He blinked remembering Rita who was stood there. The Doctor shook his head then looked at the red head. "Donna, anything?"

"She's not answering." Donna replied holding a phone to her ear meaning about trying to get hold of Martha. "What is it, Sontorans?"

"Sontarans." He nodded. "But there's got to be more to it. They can't be just remote controlling cars. That's not enough. Is anyone answering?"

"Hold on." She held her hand up trying to call once again. "Martha." She beamed then spoke into the phone again both the Time Lords walking up to her.

"Hold on, he's here." She handed the phone to the Doctor.

"Martha, tell Colonel Mace it's the Sontarans." He said into the phone, Rita pressed her ear on the other side so she could hear the conversation. "They're in the file. Code Red, Sontarans. But if they're inside the factory tell them not to start shooting. UNIT will get massacred. We'll get back as soon as we can." He paused for her to understand the information. "You got that?"

"Code Red Sontaran." They heard her through the phone. "Gotcha."

Rita frowned slightly. "Since when did Martha every say 'gotcha'?"

"It has been a while since we have seen her." He countered. She nodded slightly while he handed the phone back to Donna then moved over to the car opening it's bonnet.

"But you tried sonicing it before." Donna stated watching the two of them mess around with the car Rita flashing her sonic at it for a moment then looking under the car as the Doctor continued messing before starting to flash his sonic at it himself. "You didn't find anything."

"Yeah, but now we know it's Sontaran, we know what we're looking for." He countered continuing on the car with the Time Ladys help.

"The thing is, Doctor, Stone," Wilf spoke up, "that Donna is my only grandchild. You got to promise me you're going to take care of her."

"She takes care of me when the Stone isn't around."

"You can't help yourself getting in to trouble." Rita shook her head at him. "She keeps the both of us out of trouble to be fair though." Rita chuckled shaking her head slightly.

"Oh yeah, that's my Donna." Wilf proudly beamed at his granddaughter. "Yeah, she was always bossing us round when she was tiny. The Little General we used to call her."

"Yeah, don't start." Donna groaned out of embarrassment.

Wilf ignored her continuing on. "And some of the boys she used to turn up with. Different one every week." He thought back. "Here, who was that one with the nail varnish?"

"Matthew Richards." She muttered to him. "He lives in Kilburn now... With a man."

The Doctor jumped back pulling Rita with him as spikes suddenly stuck out of the ATMO device.

"Whoa." The Time Lords looked at it the Doctor slipping his glasses on. "It's a temporal pocket."

"I knew there was something else in there they wouldn't just start to kill people off for no reason." Rita muttered quietly to the Doctor.

"It's hidden just a second out of sync with real time." The Doctor added.

"But what's it hiding?" Donna asked.

"I don't know," they heard the voice of Donna's mother as she walked out of the house. "Men and their cars." Rita frowned slightly at the comment. "Sometimes I think if I was a car..." she trailed off noticing the Doctor with his head under the bonnet. "Oh, it's you. Doctor what was it?"

He looked up. "Yeah, that's me, this is the Stone."

"Hello." She waved. "Don't ask about how I look different, hard to explain."

"What, have you met him as well?" Wilf asked switching the subject off of the Time Lady.

"Dad, it's the man from the wedding." Donna's mother Syliva whispered to him. "When you were laid up with Spanish flu. I'm warning you, last time that man with that woman turned up it was a disaster."

The spikes then started to give off a gas, the Doctor pulled Rita away putting an arm around her waist keeping her beside him as the gas started to emit itself from the car. "Get back!" He shouted to the others.

The Doctor started to sonic at the ATMOS device as it sparked. "That'll stop it."

"I told you." Sylvia hissed. "He's blown up the car! Who is he, anyway?" She looked at Donna. "What sort of doctor blows up cars?"

"Oh, not now, Mum." Donna snapped at her.

"Oh, should I make an appointment?" She sarcastically hissed going back into the house.

"That wasn't just exhaust fumes," the Doctor smelt the air, Rita did the same and nodded with him while causiously stepping towards the car again taking a look. "Some sort of gas. Artificial gas."

"And it's aliens, is it?" Wilf asked sounding slightly worried. "Aliens?"

"But if it's poisonous, then they've got poisonous gas in every car on Earth." Donna's eyes widened as the Doctor looked at each car seeing the ATMOS sticker on the backs

"But what sort of gas and what does it do?" Rita hummed in thought trying to think looking at each car while standing beside the Doctor thinking of all of the possible things the gas could be used for.

"It's not safe." Wilf said stepping inside the car before anyone could stop him. "I'm going to get it off the street." The car then started up and thick gas came out the exhaust pipe the Doctor and Rita stepped back in confusion as Donna ran to the drivers side telling Wilf to stop.

"Turn it off." She shouted through the door. "Granddad, get out of there!"

"I can't!" He shouted hitting on the window and trying to open the door. "It's not locked! It's them aliens again!"

"What's he doing?" Sylvia turned back. "What's he done?"

"They've activated it!" The Time Lords looked around the street seeing the gas exiting out of all the cars.

"There's gas inside the car!" Donna screamed. "He's going to choke! Doctor, Stone!" They both ran to the Door as Donna moved out the way, the both of them attempting to open it the Doctor using his sonic while Rita pulled on the door.

"It won't open!" The Doctor gritted his teeth now trying to pull it open with the blonde. "It's the whole world." He realised looking up.

"Help me." Wilf begged Rita ran back to the ATMOS device and started to pull at the wires the Doctor behind her helping, they pulled all of the engine wires out but the gas continued to fill the car, the Doctor and Rita helplessly ran to the middle of the road looking around in alarm not able to do anything.

"Get me out of here!" Wilf screamed again then slowly collapsed inside the car as the red head cried out for the Time Lords to help her.