The doctor and Sasha returned to Earth to se Chris' work on House of the Doctor. Sasha discovered her family had been teleported to Earth after she freed Sto. Chris was investigating a strange disease found in dirty or chemical water. The doctor, Celia and Victoria went on a boat on the Thames to take a water sample. The doctor studies it, his boat was sunk and Celia got infected by the disease. When the doctor arrived back at House of the Doctor he found a man hole outside which led to the source of the disease, Sasha and Nik went down into it and Nik got infected with the disease and came after Sasha. Sasha ran through the tunnels and found a room containing four creatures called Methadotics
and back at House of the Doctor the water pipes burst and water leaked through the ceiling infecting Jim (Sashas' Father) and The Doctor...

Maxine was crying, Chris was pulling her back, she was struggling in his arms
"We have to go!" shouted Chris "The doctor is infected and we need to make a cure for him! The analysis is on the computer!"
Chris, Maxine, Linda and Gina all backed out of the room and closed the door behind them.

Sasha was backed against a wall, the Methadotic with the green cloak was scanning her, it had a white ball with a green light coming from it
"Okay" he said this one sounded a bit like Mr Bean "She is half Sto half human"
"Really?" said the croaky voiced pink witch doctor creature "How fascinating"
He slowly glided towards Sasha
"And your name is Sasha Ood" he said "and from the legends of the Ood, you created them by giving up half of your brain! And it magically grew back! I bet you can't cure yourself of our disease!"
"Why?" said Sasha angrily "Why did you create a disease?"
"To test our medicines!" said the pink Methadotic "This disease is like your cancer! We know the cure for cancer! And many other things! But we don't know the cure for this! And we found we can cure it using certain minerals on Earth!"
"Well why don't you let me help you cure this place?" said Sasha trying to reason with these intelligent creatures "You don't have to infect a whole planet!"
"No!" said the Methadotic "Because it doesn't end there! We are trying out this cure on a worldwide scale! Our whole planet is infected! They are all in a deep sleep!"
"What about Nik?" said Sasha "He walked towards me! He is out there! Probably banging on that door!"
The pink Methadotic just ignored her
"You are useless!" it said "You don't know anything!"
Sasha shook her head, she wasn't going to let them infect a whole planet...

Chris, Maxine, Gina and Linda all ran into one of the computer rooms
"Gina!" shouted Chris "keep an eye on all the water pipes and the ceiling! Linda keep an eye on the window to see any signs of the disease spreading!"
Chris typed onto the computer
"Come on!" he said "come up results!"
Then the analysis came up on the screen
"Okay" said Chris "This disease has three chemical elements, Golium Hydrate, Aga Moride and Saturn Dextri, if we can find what chemicals they react with on Earth then we can cure it!"
Then suddenly a window smashed open
Linda screamed, everyone ducked
It was Rochelle Docherty, who stopped Giant Worms eating the Earth a year ago
"Perhaps I can help" she said

Sasha was still against the dark wall, she was looking at the room, the dark room with orange lights, some benches and glass bottles with chemicals in them. She watched the creatures examining the chemicals
"Why can't I help?" shouted Sasha "Why are you keeping me here?"
The pink Methadotic turned away from its work
"You need to learn to shut up!" it said "Perhaps I can show you the real face of our kind! Our greatest silencer!"
"What?" said Sasha beginning to panic
The Methadotic began to reach up to its Witch Doctor mask, Sasha began to try and back away but the creature got closer
"Do you want to see behind the mask?" said the creature grimly
It ripped off its mask to reveal a sphere shaped head with a huge red eye and a huge mouth with long fangs
Sasha screamed in terror and horror a long piercing scream...

Rochelle had come to the computer
"Okay" she said "I've been in London for a week and I have found bodies all infected with this disease and I found the chemical elements with help from my friends in Ealing, they also found out what the disease is vulnerable to"
"What is it?" said Victoria
"The disease is highly vulnerable to helium" said Rochelle
"What?" laughed Chris "Helium?"
"Yeah" said Rochelle "Mr Smith explained it but it didn't make much sense"
"So what?" said Maxine "we raid a birthday card shop?"
"We could" said Rochelle "But I have a tank of helium here and if we can somehow transmit that throughout London then we can cure this disease"
"We can use the replicators!" said Chris "The machine that expands what you put in and rains it throughout a certain area!"
"How on Earth did you make one of them?" said Rochelle
"TIOAEAI" said Chris "on the planet Dom they can make their own weather"
"Then let's do it!" shouted Rochelle happily
Then the doctor and Jim burst into the room
Rochelle gasped
they were walking like zombies reaching out for everyone
"RUN!" shouted Linda, she opened a grid in the floor
It lead into a ventilation shaft
Linda climbed in, followed by Chris, then Maxine, then Rochelle , Victoria and finally Gina. They were crawling through the vents in single file, round corners and looking up to find an entrance to a room
"BINGO!" shouted Linda she had found the hallway which lead to a staircase which then lead to the replicator room. Linda opened the grid and everyone climbed out, they then turned to face all of the employees, hundreds of scientists and technicians all with the disease
"RUN!" shouted Maxine
They dashed up the stairs

Sasha woke up to the green witch doctor staring at her
it was examining her
"We still can't find a cure for this disease" it said "I've looked in her brain and there's nothing! But it reacts differently in humans! Humans walk! They march after people trying to infect them!"
"Good" said the pink Methadotic "Then our work is about done"

On the streets of London people were infected and walking the streets pushing people into the Thames and grabbing them, Celia was there doing the same.

Back at the Methadotic lab the orange witch doctor turned on a hologram screen. The news was on it
"over 200 people have been infected with a tropical disease and are walking the streets of London trying to infect others" said the reporter
she then jumped out of her seat as a camera man covered in the disease advanced to her and grabbed her and infected her...
Sasha just closed her eyes in disgust
"See what you've done?" she said
"Yes" said the pink Methadotic "the whole plan is working!"

Linda, Victoria, Chris, Rochelle and Gina were all running in a corridor. Pipes were bursting behind them, filling the white corridor making sure they wouldn't get back down the stairs.
Gina stopped running and turned around to face some of the zombies
"You guys run!" she shouted "I'll hold them off!"
Chris looked back unsure... everyone ran
Gina blasted at walls, not hitting the zombies though; she didn't want to do that. She backed away, the red marked zombies refused to give in. Gina turned to run but was faced with the doctor who grabbed her and she got infected, her green Silurian skin infected with the disease...

As everybody ran further through the corridor Linda was getting slower
"Chris!" she shouted "I can't run more!"
She stumbled through a door into a lab, she locked the door behind her. The lab was small and had an MRI scanner in it, salvaged from The Royal Hope Hospital after it was programmed to destroy half of the Earth. She backed far into the room so that the zombies wouldn't see her. But the advancing zombies saw her; they were pressed against the door, trying to push it open. Linda ran behind a glass sealed area and locked it. The infected zombies burst through the door and into the room they slowly advanced for the glass...

Everybody was still running through a long white corridor
"How much further does this place go on for?" shouted Rochelle
"Not that far!" shouted Chris "It is a big house you know!"
then red gung fell from the ceiling in front of Victoria
"VICTORIA!" shouted Rochelle
"Okay" said Chris calmly "I want you to get down to that sewer somehow and find Sasha and I'll put the helium into the replicator!"
Rochelle nodded
She found a window and opened it, the drop wasn't too bad, she jumped onto the thick grass below her and ran to the sewer entrance, she climbed down the manhole into the dark leaky sewer to find Sasha...

Sasha remained where she was, backed up at the wall looking at the lab full of medicines; the witch doctors were still working
"Have you found a cure yet?" said Sasha
"No" said the pink witch doctor "we don't accept help from Cyborgs!"
He grinned at Sasha as he said that. Sasha looked at him, she felt a lump of anger in her throat, she wanted to kill him, but she was better than that...
Then the heavy thick metal door was pushed open with great force and out of the smoke came Rochelle
She looked around
"Ooh" she said "Fascinating! A whole base underneath Sashas' street!"
"What are you doing here?" said Sasha
"Saving your life" said Rochelle with no effort, she clapped her hands "So! You lot created the mayhem above?"
The witch doctors just looked at her, reluctant to answer
"I'll take that as a yes" said Rochelle "and those are alien chemicals you have in those bottles?"
"Yes" said the green witch doctor
"and some of them will be highly explosive?" said Rochelle
the witch doctors just looked at her
"Rochelle don't you think about it!" said Sasha "You have to be reasonable!"
"And were you reasonable?" said Rochelle
"Yes" said Sasha
"well that just goes to prove that some people never learn!" said Rochelle taking out a lighter
She flicked the switch and a small flame rose from inside the lighter and the consequences of that small move were huge

Bottles exploded into balls of flames, all around the room things were exploding, fire everywhere
Sasha screamed
Rochelle opened the door
"RUN!" she screamed
"NOOOOOOO!" screamed the witch doctors as the flames exploded in front of them

Chris had now inserted the helium tank into a small box below a chimney, he pressed a red button on the small chrome box and the helium was shot up through the chimney and spread across London... all over London the red rash faded off the people and they fell unconscious... the disease evaporated from the river and the water pipes and the sewers...
"YES!" cheered Chris

Victoria watched in amazement as the diseased people fell unconscious against the glass.

Sasha and Rochelle were running through the sewer as it exploded behind them, they climbed onto the street.
A huge crack was ripping through the road on the street like an Earthquake then it stopped. The cracking stopped and the explosion was now just fire...
Sasha and Rochelle looked ahead at the street amazed. Rochelle smiled at her victory. Sasha was just shocked. The doctor came out of the house.
He smiled; his friends on Earth had worked together and defeated evil and not one of them dead. He smiled at their victory

The doctor, Sasha, Chris and Victoria were in the doctors lab.
"Well" said Chris "Victoria and I will get cleaning up, you two go off and have fun"
"Are you sure you don't to see more?" said Sasha to Victoria
"Yeah" said Victoria "I'll stay here, get used to the future first and maybe afterwards I'll come with you"
Sasha nodded and smiled
"I look forward to it" she said
She and the doctor walked into the TARDIS . It faded away. Chris and Victoria smiled

Nik lay on the street. He woke up. his sight was blurred. He stood up. he could make out a woman standing in front of him, with a red dress on
"How did I get here?" he said rubbing his head
"That was me" said the smooth woman "And don't worry my soldier, your time is almost up and you will be free!"