52 deaths at the exact same moment, worldwide. Aliens. Are you staying for tea? As the Sontaran chant continues, the Doctor stands in the middle of the street, powerless to stop the world from being consumed in the fumes. But there's got to be more to it, they can't be just remote controlling cars. Donna pulls down a control with her left hand and the TARDIS lurches. Fit ATMOS in your car, reduces CO2 emissions to zero. GENERAL STAAL: There is an enemy of the Sontarans known as the Doctor. GENERAL STAAL: We say the same of humans. How many ATMOS devices have been installed? In a small room, Martha is doing a health check on an ATMOS worker. Martha, Donna, and the Doctor stand by as UNIT soldiers, trucks, and vans roll by. PRIVATE GRAY: Help us! Thanks for letting me take the lead. The Doctor has his sonic screwdriver out and is fiddling with the car engine, and the ATMOS that is attached. The Doctor runs between the engine and the door, trying to stop the gas and free Wilf at the same time. The jeep swerves off the road. The spikes from the ATMOS device suddenly let off a cloud of white gas. They are close. They look at Luke Rattigan's profile on a computer. WILF: Oh, an alien hand...! We see Martha Jones, standing in an alleyway with a phone.
Plan: A: Martha Jones; Q: Who calls the Doctor for assistance? A: an investigation; Q: What is UNIT conducting? A: TARDIS; Q: What is the name of the Doctor's time machine? A: an ATMOS factory; Q: What does Martha authorise the raid of? A: a satellite navigation system; Q: What is ATMOS marketing? A: young prodigy Luke Rattigan; Q: Who developed the ATMOS system? A: carbon dioxide emissions; Q: What does the ATMOS system reduce to zero? A: the Doctor's help; Q: Who did UNIT request help from? A: concerned about 52 early simultaneous deaths; Q: What is UNIT concerned about? A: Rattigan's private school; Q: Where does the Doctor investigate the ATMOS system? A: an alien warrior race; Q: What is the Sontarans? A: Sontarans; Q: What alien race is behind the ATMOS plot? A: Donna; Q: Who returns home to her mother and grandfather? A: a poisonous gas; Q: What does the ATMOS device emit? A: the car; Q: What does Wilfred try to take off the road? A: all 400 million ATMOS devices; Q: How many ATMOS devices are installed in cars worldwide? A: battle; Q: What are the Sontarans preparing for? Summary: Martha Jones calls the Doctor for assistance during an investigation by UNIT . Minutes after the TARDIS materialises, Martha authorises the raid of an ATMOS factory. ATMOS is marketing a satellite navigation system developed by young prodigy Luke Rattigan . The system also reduces carbon dioxide emissions to zero; UNIT requested the Doctor's help because the technology may be alien, and they are also concerned about 52 early simultaneous deaths that occurred spontaneously. The Doctor investigates the system at Rattigan's private school and discovers a plot by an alien warrior race known as the Sontarans . Instead of an outright invasion, they are taking control with a combination of human clones, mind control, and ATMOS; Martha is captured and cloned to provide a mole within UNIT. Donna returns home to her mother Sylvia and grandfather Wilfred . The Doctor investigates the ATMOS devices and discovers it can emit a poisonous gas. Wilfred attempts to take the car off the road, but is trapped when all 400 million ATMOS devices installed in cars worldwide are activated. The Doctor stares helplessly at a street full of cars emitting the gas, while the Sontarans prepare themselves for battle.