Director: Richard Clark (II)
Show Stars: Freema Agyeman (Martha Jones (Season 3 - )), David Tennant (The 10th Doctor (Season 2 - ))
Guest Stars: Ardal O'Hanlon (Thomas Kincade Brannigan) , Jennifer Hennessy (Valerie) , Struan Rodger (The Face Of Boe) , Anna Hope (Novice Hame) , Travis Oliver (Milo) , Lenora Crichlow (Cheen) , Bridget Turner (Alice) , Georgine Anderson (May) , Simon Pearsall (Whitey) , Daisy Lewis (Javit) , Nicholas Bolton (Businessman) , Erika Macleod (Sally Calypso) , Judy Norman (Ma) , Graham Padden (Pa) , Lucy Davenport (Pale Woman) , Tom Edden (Pharmacist 1) , Natasha Williams (Pharmacist 2) , Gayle Telfer Stevens (Pharmacist 3)
Production Code: NCFT083D
In the distant future, a couple is driving along the motorway, when their vehicle is struck repeatedly. They call the police for assistance, but an explosion rips through the rear section as the couple scream in terror.
The Doctor is trying to get Martha back after her one trip but suggests she might go on one trip to a different planet in the future. She suggests they go to his home planet but he demurs. Instead he takes her to New York in the year 5,000,000,053. They emerge and end up in an alleyway in the rain.
Elsewhere, the Face of Boe tells a cat-nun to find the Doctor and she goes after him… with a gun.
The Doctor taps into a local broadcast while Martha wonders why he’s taking her to the same planet he took Rose to. A number of shop owners open their windows and all try to take advantage of their new customers by selling them mood drugs. A woman comes by to purchase “Forget” and mentions that her parents disappeared on the motorway. The Doctor takes an interest but she takes the drug before she can give him more detail. An armed man and woman then suddenly grab Martha and haul her into a building before the Doctor can act. He follows after them but they render Martha unconscious with a drug, and get her into a vehicle and make their escape before the Doctor can catch up to them.
The Doctor returns to the storeowners who warn that the Doctor might as well forget Martha; she was kidnapped as the pair need three people to get into the ‘fast lane’ of the motorway. The Doctor stalks off, but not before telling them that he is closing down their street later.
Martha wakes up and tries use her kidnappers’ gun to force them to take her back, but they reveal that it isn’t real. They introduce themselves as Cheen and Milo, and promise to drop her off once they get where they’re going. However, they warn her that it will take them six years to go the ten miles that they’re travelling.
The Doctor breaks in to the motorway (which is a large tunnel) and finds himself overlooking a vast traffic jam. He starts to choke and a cat-man and his companion invite him into their car. They introduce themselves as Thomas and Valerie and quickly take advantage of a ten-yard gap in traffic. The couple introduces the Doctor to their children, who were born on the motorway, and say they’ve been driving for 12 years to cover five miles. They’ve already moved past the last lay-by, and as such the Doctor has no choice but to remain on-board.
Cheen and Milo explain to Martha how they’ve managed to get by so long, with extended stocks of food and constant recycling. The Doctor tries to call the police but is placed on hold, and Valerie and Thomas warn the motorway is sealed off and calls can’t be made out of it. They call an elderly married couple, the Cassinis, to try to find Martha and thanks to their car-spotting hobby they identify the car Martha is in. However, there’s no way the Doctor can get to them in their fast lane.
Martha and her drivers hear a growling noise. Milo believes it’s just mechanical noises, but Cheen asserts it’s some legendary unseen creatures. Meanwhile, the Doctor insists that Thomas go down to the fast lane but Valerie says it’s too risky. The Doctor calls the Cassinis back to confirm they’ve never seen any official vehicles in the whole 20+ years they’ve been on the motorway. Newscaster Sally Calypso comes on to reassure all the drivers that everything is fine and they haven’t been forgotten, and everyone joins in a chorus of “The Old Rugged Cross.”
Cheen and Milo get into the fast lane while the Doctor resolves to go on his own, leaving through the bottom hatch and dropping from car to car to get to the bottom faster lanes. Meanwhile something attacks Martha’s car and another driver warns them that something is in the fog and they need to switch lanes. Their car is also under attack and they are cut off. Martha tells them to get moving no matter what.
The Doctor gets to the last lane before the fast lane, with nothing below but a thousand foot drop. Meanwhile, the Face of Boe’s agent bursts into Thomas and Valerie’s car and demands to know where the Doctor is.
The Doctor hacks into the motorway computer system, and sets the ventilation to create a breeze, which reveals crab-like creatures below: the Macra. The creatures start to attack Martha’s car as it swerves between them. They cut the engine which keeps the creatures from sensing them. However, they have only a limited air supply if the engines aren’t running.
The Doctor explains to his current driver that the Macra feed on gas pollution and once built a small empire using humans as slaves. The cat-nun arrives and greets the Doctor, and introduces herself as an elderly Novice Hame. She asks the Doctor to come with him so she can redeem herself, but when he refuses she grabs him and teleports him to the Overcity, to the Senate Chamber. However, all of the senators are 24 years dead, due to a new drug called Bliss which mutated and became airborne. Everyone in the Overcity died but they managed to seal off the lower levels and now the Motorway drivers are the only survivors.
The Face of Boe is present and Novice Hame explains she was made his caretaker as penance for her sins. She explains that the Face of Boe wired himself into the motorway to maintain it with his life-force, while the rest of the galaxy put New Earth under quarantine for 100 years.
Martha tries to explain to Cheen and Milo that the Doctor will save them, but they’re sceptical. Milo decides to believe her and reactivates the vehicle, then drives through the Macra. The Doctor picks them up on the sensors and powers up the system to maximum but loses power. The Face of Boe gives up the last of its energy so that the Doctor can open up the vents above the motorway. The Doctor gets on the broadcast system, shuts off the Sally Calypso pre-recorded hologram, and tells everyone to drive upward so they can clear the fast lane. The Doctor tells Martha to drive up and they fly clear of the Macra and up into the sun.
All of the drivers are rescued and Martha and the others head for the Senate building. Martha arrives to find that the Face of Boe’s containment vat has shattered and he is dying. Before he dies, the Face of Boe has one final message to give the Doctor: “You are not alone.”
The Doctor and Martha return to the TARDIS after making sure the storeowners are shut down. Martha wonders what the Face of Boe meant but the Doctor appears unconcerned. However, Martha demands answers from the secretive Doctor. The city dwellers begin to sing and the Doctor explains to her that he lied and that he is the last of the Time Lords, and that the rest of his people died in a war against the Daleks. He describes his home planet in glowing detail while overhead, the Overcity is reborn.