'The Sontaran Stratagem' (Story Code 4.4) by Helen Raynor

“Do you know how many cars there are on planet Earth? Eight hundred million. Imagine that. And if you control them, you make eight hundred million weapons…” – The Doctor

While investigating claims that ATMOS – the Atmospheric Emission System, a new satellite navigation and low carbon emission system for cars – is dangerous, reporter Jo Nakashima is discovered by the personnel of the Rattigan Academy, and rudely escorted from the premises. As Jo drives off in her car, she attempts to warn the Unified Intelligence Taskforce, but the vehicle’s ATMOS device takes over, seals the car, and then plunges it off a bridge into a river… Elsewhere, in the time/space vortex, the Doctor is regretting allowing Donna the chance to pilot the TARDIS; their unstable flight is interrupted by the sound of a mobile phone ringing – the Doctor’s former companion, Doctor Martha Jones, wants his help back on Earth… Materialising the TARDIS outside the central depot of ATMOS, the Doctor shares a happy reunion with Martha, and is rather unnerved that she instantly hits it off with Donna; in fact it is Donna who is the first to spot that Martha is now engaged – to Thomas Milligan, the doctor Martha met while fighting against the oppression of the Master. As the Doctor and Donna watch, Martha pulls out a walkie-talkie and order the commencement of ‘Operation Blue Sky’; squads of U.N.I.T. soldiers immediately converge on the factory and arrest the entire workforce, in a search for “illegal aliens”. Elsewhere, a real alien watches the events unfolding at the factory… After Martha introduces the Doctor and Donna to U.N.I.T.’s current commanding officer, Colonel Mace, the Time Lord learns that the day before, fifty-two people in eleven different time zones across the world all died simultaneously; each of the victims had an ATMOS device fitted with their car – a device suspected to be of alien origin… Meanwhile, two U.N.I.T. soldiers, Privates Harris and Gray, search the complex and find a laboratory guarded by two zombie-like employees; investigating the room they discover a nutrient tank containing a half-formed humanoid creature, but before the soldiers can contact their command, they are confronted by a squat, armoured alien: General Staal of the Tenth Sontaran Battlefleet. Easily overpowering then with his weapon, Staal orders his workers to seize the soldiers and condition them for use in his stratagem… While the Doctor studies the ATMOS device, Donna looks through the company’s files and finds that none of its personnel have ever taken a day off sick; Colonel Mace immediately orders Martha to set up a medical post to examine every employee. Learning that ATMOS was invented by child genius Luke Rattigan, the Doctor decides to pay the teenager’s academy a visit; he obtains a jeep from Colonel Mace, along with a driver, Ross Jenkins. When Donna tells Martha that she plans to warn her mother of the ATMOS device in her car, Martha gives her some advice: it may be fun to share the Doctor’s adventures, but it can also be dangerous – not only to Donna, but to her family as well. Martha discovers that the ATMOS employees have an irregular heartbeat, and appear to have been hypnotised into working twenty-four hours a day; she is about to continue her investigations when she is approached by the hypnotised Private Harris and Private Gray, who advise her that Colonel Mace needs to speak with her; however, instead of taking her to their commanding officer, the soldiers take Martha to the secret laboratory, where she is strapped to a complex set of equipment… Dropped off at her street by the Doctor and Ross, Donna is overjoyed to be reunited with her grandfather, Wilf; she tells him of her travels with the Doctor, but chooses to withhold her exciting adventures from her overbearing mother. Arriving at the academy, the Doctor and Ross meet the obnoxious eighteen-year-old, Luke Rattigan; looking around the estate, the Doctor is intrigued by the complex apparatus under development by the staff – equipment that could be used to move Luke and his people to another planet. Activating a nearby teleport pod the Doctor transports himself to the control room of a warship in orbit around the Earth – a room filled with Sontarans; the Doctor quickly reverses the controls, but one of the alien warriors follows him back to the academy. Taunting the Sontaran, the Doctor is able to goad him into removing his helmet; the alien reveals his identity as General Staal, known to his fellow warriors as ‘Staal the Undefeated’. Using a handy squash racket and ball, the Doctor is able to hit the Sontaran’s probic vent – the alien’s only weakness, situated at the back of his neck – allowing the Time Lord and Ross to make a hasty exit from the building. Recovering from the attack, Staal teleports himself and Rattigan back to the mothership. After giving the order to begin the final phase of his plan, the Sontaran officer then despatches his subordinate, Commander Storr, to oversee the infiltration of U.N.I.T. Teleporting down to the ATMOS lab, Storr watches with satisfaction as a clone of Martha is created within the liquid of the nutrient tank... Learning the Doctor’s name from Rattigan, Staal is extremely pleased; the Doctor is a legend in his race’s history, and the Sontaran general will revel in the death of the last of the Time Lords… Tracking the Doctor via the ATMOS system in the U.N.I.T jeep, Staal takes over the vehicle and sends it hurtling towards a nearby river; however, the Doctor is able to outwit the device with logic, stopping it just before it drives him and Ross to their deaths. Escorted by Private Harris and Private Gray, the evil clone of Martha resumes her work for U.N.I.T. The Doctor returns to Donna’s house, where his friend is astonished to learn that the Time Lord has previously met her grandfather and mother. The Doctor phones U.N.I.T. to warn Colonel Mace of the Sontaran threat – unaware that the Martha Jones who takes his call is working for the invaders. Examining the ATMOS device in her mother’s car, the Doctor discovers the appliance is equipped with a temporal pocket that is set to release a poisonous gas into the atmosphere. Aboard the Sontaran mothership, Staal detects the premature activation of the ATMOS device in the Nobles’ car, and surmises that the Doctor survived his attack; satisfied with the results of Rattigan’s earlier test run of the ATMOS devices, Staal orders the activation of all the units across the world – all four-hundred million of them. He then mobilises his fleet for the final stage for the subjugation of Earth, and watches with satisfaction as dozens of spherical ships detach from the main vessel and head towards the planet below... Wilf decides to move his car from the street, but the ATMOS device seals the doors and windows before releasing the deadly gas inside the vehicle The Doctor desperately tries to save the choking Wilf, but his attempts prove useless. All across the world, millions of cars equipped with the ATMOS devices begin releasing their deadly gas into the atmosphere…

David Tennant (The Doctor), Catherine Tate (Donna Noble), Freema Agyeman (Doctor Martha Jones), Bernard Cribbins (Wilfred Mott), Jacqueline King (Sylvia Noble), Rupert Holiday Evans (Colonel Mace), Ryan Sampson (Luke Rattigan), Christopher Ryan (General Staal), Dan Starkey (Commander Skorr), Eleanor Matsuura (Jo Nakashima), Clive Standen (Private Harris), Wesley Theobald (Private Steve Gray), Christian Cooke (Ross Jenkins), Worker (Rad Kaim), ATMOS Voice (Elizabeth Ryder)

Directed by Douglas Mackinnon
Produced by Susie Liggat
Executive Producers Russell T. Davies, Phil Collinson and Julie Gardner
A BBC Wales production

TX:
26th April 2008 @ 6.20 pm

Notes:
*Featuring the Tenth Doctor and Donna, and reintroducing Martha

*Part one of a two part story

*As well as David Tennant and Catherine Tate, Freema Agyeman is also credited during the main titles