Martha: How long's it gonna take?
Cheen: [nonchalantly] Oh, six years?
Written by Russell T Davies.
The Doctor tells Martha that her one trip is over, and she can go home now... unless she wants to travel more. No reason, really, he'd just like to travel more. In fact, he'd like to take her to the future and how about another planet? Martha is all for it, but throws him by asking if they can visit his home. Planet of the Time Lords, after all; got to be worth a look? The Doctor finds himself agreeing, fondly recalling the burnt orange sky, mountains covered in red grass, a gleaming city under its mighty glass dome...
... but nah, why would he want to go back there? Better idea: New New New, etc., York. Where drugs are cheap, legal and socially acceptable. Where people inexplicably look like cats. Where traffic never moves. Where the Doctor also took Rose once.
The Doctor even tries to make the same little jokes he made to Rose when he first took her there, but they just don't work as well when Rose isn't around to hear them. By now, Martha's figured out that she's the Doctor's "rebound", and she doesn't like it one bit. Also, the TARDIS has taken them to the undercity slums, where things aren't quite as happy as they are above the smog.
Martha gets kidnapped by a couple named Milo and Cheen so that they can have enough people in their car to get access to the elusive fast lane. The Doctor chases after her... into the Traffic Jam from Hell.
Before he dies of extreme toxic smoke inhalation, though, he gets picked up by Thomas Kinkaide Brannigan and his wife Valerie. Estimated time of arrival? Oh, another six years or so.
The Doctor, not wanting to wait that long, jumps from car to car, and tries climbing down to Martha's spot, but he can only get so far.
Meanwhile, giant evil crabs that feed off pollution have snatched Martha's car out of the air and are hell-bent on eating her. The Doctor quickly recognizes them as the Macra and notes that they've devolved into mindless beasts over time, living in the depths of the motorway. Even if he could get there, there's hardly any way to get back.
The Doctor will not be deterred, but before he can continue he's caught by Novice Hame, one of the cat-nurse-nuns he met during his last trip here. She transports him against his will to the upper city, where the only other remaining "person" is the Face of Boe, the oldest being in the galaxy, who's the only thing powering the motorway and keeping the rest of demi-humanity alive. It turns out that the planet's inhabitants all got wiped out by an unstoppable plague that killed everyone (including itself). And all the motorways are closed, and have been closed for years. All those cars with all their eternal fuel and food supplies are driving in eternal circles around the deadly city smog.
The quarantine placed on the planet was set to last 100 years, so it has to be released manually. The Face gives his life to open up the motorway exits and save Martha. The Doctor opens the gates and all the cars ascend into the bright upper city, with the people inside praising Jehova for saving them from the Macra.
Martha refuses to leave until the Doctor tells her just what he is and what's going on. The Doctor sits down with her and tells his story from the beginning, starting with "there was a war"...
- Absurdly Sharp Claws: The Macra can be found at the bottom of the motorway in New New York. In the "fast lane" you can reach speeds of up to thirty miles per hour! (Usually taking six years to get to Brooklyn from Queens!) However, this comes with a risk: the potential of being sliced and mauled by the Macra. What's even scarier is that you only really get to see these claws above the fumes.
- Action Prologue: The episode begins with a couple's flying car on a motorway being attacked by an unseen menace.
- Adventurer Outfit: Brannigan is wearing goggles, a scarf and a leather jacket. He's basically a suburban dad.
- Adults Are More Anthropomorphic: We meet an interspecies couple human female and catman male. They recently had a litter of children who all look like normal kittens (because they were all played by kittens).
- Aliens of London: Despite being New New York, everyone there (barring Brannigan and the news anchor) sounds very British due to the TARDIS' Translation Convention.
- Alien Sky: As the episode ends, the Doctor describes Gallifrey's sky, and the way when the red of the sun hit the silver trees it looked like the sky was on fire...
- All There in the Manual: As to how the Macra ended up in the motorway in the first place, they were in New New York's zoo, and got free when everyone else died.
- Always Save the Girl:Brannigan: This Martha... she must mean a whole lot to you.
The Doctor: Hardly know her. I was too busy showing off.
- American Gothic Couple: The couple in the opening who are attacked by the Macra look like this, but they are far from stoic. They are terrified.
- Apocalypse How: The Plague from the Bliss drug has effectively caused a mild Class 2 to the population, wiping out literally everyone on New Earth who wasn't sealed off in the Undercity at the time (or in the Face of Boe and Novice Hame's case protected by the Face's smoke). From what Novice Hame says, it sounds like the virus didn't just affect the sentients but also the entire biosphere outside of the Undercity, thereby making it a Class 4.
- Apologetic Attacker: Martha's kidnappers frantically say "sorry" to the Doctor even as they drag Martha off.
- Art Imitates Art: Ma and Pa were based on the farming couple in the painting American Gothic, both having identical hairstyles, glasses and fashions.
- The Atoner: Novice Hame, the cat nun assistant to the Face of Boe, was the survivor out of the three named cat nuns from "New Earth".
- Back for the Dead: The Face Of Boe, last seen at the beginning of the previous series, returns in time to sacrifice himself to rescue the people trapped on the motorway.
- Big Word Shout: MAAAAAAAARTHAAAAAAAAAAAA!
- Binary Suns: The Doctor talks about Gallifrey's in the beginning.
- Cat Folk: The Sisters of Plenitude weren't the only inhabitants of New New York to be cat-people, and in this episode we see several more, most prominently Brannigan.
- Continuity Nod:
- Crapsack World: The other side of New New York isn't a nice place. Due to the exhaust buildup the air is filthy, millions of people are trapped in their cars for years (if they ever get to their destination at all), and if you go down into the fast lane you stand a very good chance of being eaten by the Macra.
- The City Narrows: The other side of New New York is less dazzling than the previous.
- Cute Kitten: The cute factor is the most likely reason for an anthropomorphic cat and a demi-human woman having a litter of seemingly ordinary kittens.
- Dead-Hand Shot: The prologue has one as one of the car inhabitants slaps their bloody hand against the screen while being killed by the Macra.
- Death of a Child: The second car on-screen to fall victim to the Macra is a car carrying two young twins.
- Disco Dan: The Cassini "sisters"; they're old ladies born in the far future and they still decorate their car stereotypical for the 30s-40s.
- Dominant Species Genes: We briefly meet a Catman and human female husband and wife, who have a litter of kitten offspring.
- Drugs Are Bad: Both Martha and the Doctor are unamused by a street populated by drug-dealing booths that sell everything from "Happy" to "Forget" to "Honesty", and a contaminated batch of "Bliss" killed all of New Earth's population apart from New New York's undercity.
- Elephant in the Living Room: No one wants to talk about why they've never seen any emergency vehicles.
- Everybody's Dead, Dave: A virus that started off in a drug spread across the entirety of New Earth, killing everyone it came into contact with. The people in the undercity survived because they were sealed off before the virus could get to them, and Novice Hame only survived because of the Face of Boe.
- Evolutionary Levels: The Doctor wonders if the Macra have devolved, considering they used to be intelligent but now they're just huge mindless monsters.
- Evolutionary Stasis: Despite being said in previous episodes to have changed, the humans still look human.
- Fate Worse than Death: Going to the motorway is grim indeed. Sitting in the eternal traffic jam, going round and round year upon year upon decade, with the only interaction being with whoever you already have with you or can phone. And everyone goes to the motorway in the end.
- First Time in the Sun: After spending their lives on an underground motorway, the inhabitants of New New New (etc.) York are enthralled when the Doctor fixes the transport system so that they can fly up into the sky and city for the first time.
- Flat "What": Martha's displeased and surprised reaction to the length of time a ten-mile/sixteen-kilometre journey will take.
- Flying Car: In sufficient abundance to result in three-dimensional multi-lane motorways and horrifying flying traffic jams.
- "You are not alone."
- Thomas Kinkaide Brannigan: "Til the Journey's End".
- Formerly Sapient Species: In the ages since their first appearance, the Macra have "devolved" (in the Doctor's words) since their first appearance from powerful, mind-controlling creatures to beasts who live only to feed.
- Futuristic Superhighway: The Doctor returns to the planet New Earth to discover one of these in the city of New New York stuck in a massive traffic jam because the entire population of the rest of the planet died in a virulent plague, and the undercity, including the motorway, was sealed off to protect the population. Afterward, there wasn't enough power to reopen it. If that wasn't bad enough, there are devolved Macra which escaped from the zoo living on the bottom of the pollution-choked tunnel waiting to snatch anyone who tries to use the 3-person "fast lane".
- Giant Enemy Crab: The Macra. They can be found at the bottom of the motorway in New New York (on New Earth). In the "fast lane", you can reach speeds of up to thirty miles per hour! (Usually taking six years to get to Brooklyn from Queens!) However, this comes with a risk: the potential of being sliced and mauled by the Macra. What's even scarier is that you only really get to see the claws above the fumes.
- Half-Human Hybrid: Brannigan has children with a human woman. They look exactly like normal kittens.
- Hand-or-Object Underwear: The woman in the "nudist" car is holding a magazine when the Doctor drops in.
- Happily Married: There are two (maybe three) married couples in this episode and they all get along well for being stuck together in a small car for decades.
- Brannigan and Valerie playfully bicker.
- The Cassinis hold hands during the hymn.
- Heroic Sacrifice: The Face of Boe sacrifices himself to provide enough energy to open up the motorway in which the last surviving citizens of New New York are trapped, releasing them from both the doomed fate of driving on the motorway forever and from being preyed on by the Macra below. Specifically, this saves the life of Martha and numerous other minor characters met throughout the episode who are stuck in cars on the motorway with no escape.
- Hood Hopping: The Doctor does a three-dimensional version to find Martha in the traffic jam.
- Hypocritical Humour: Brannigan refers to the Cassinis as "sisters", claiming that he's a traditional type despite being a catman married to a humanoid.
- I Ate WHAT?!: Martha is disgusted to learn that food in the cars is made from recycled waste, after taking a few bites of a cracker offered to her.
- Interspecies Romance: The Brannigans. She's demi-human, he's a cat-man; their kids are a litter of kittens (who can say "Mama").
- Laser-Guided Amnesia: "Forget", with variable amounts of amnesia dependant on just how much the buyer wants to forget. The Doctor and Martha meet a young woman buying some when her parents have gone to the motorway, and are unable to stop her applying the patch.
- Liar Revealed: At the end, the Doctor is forced to come clean about the fact that he's the Last of His Kind, which he had previously been trying to keep Martha unaware of.
- Muck Monster: The Macra live in and feed on car smog.
- Naked People Are Funny: As the Doctor tries to track down the carjackers who took Martha, one of the couples occupying the cars he climbs through is a pair of nudists. He doesn't hang around long enough to bother giving them an alibi.
- National Stereotypes:
- Irish Catman.
- That one guy who really went out of his way to look British. Bowler hat, something about manners...
- New Neo City: New New New New New New New New New New New New New New New New York. Again.
- No Antagonist: A rare Doctor Who story with no sentient villain. Even the virus that wiped out the entire population of New Earth has long since perished, having had no one left alive to infect and propagate itself with.
- Noodle Incident: The Doctor's meeting with Janis Joplin that led to her giving him his Badass Longcoat is only mentioned in brief.
- No Product Safety Standards: The future society nearly collapsed because of drugs that "blissed" you to death.
- Nothing Is Scarier: We don't really see the Macra beyond their claws and eyes. Makes it all the more terrifying whenever they peel open a car like a tin can and eat the people inside.
- One Drink Will Kill the Baby: When Martha finds out that Cheen is pregnant, she rips off Cheen's Honesty patch in disgust.
- One Steve Limit: Cheen's boyfriend isn't the first Milo to appear in the new series.
- One-Word Title: "Gridlock".
- Police Are Useless: A call to the police gets the Doctor put on hold. A call to the Cassinis reveals that there aren't police.
- The Plague: The Bliss Virus began as a recreational drug and then mutated. It turned deadly and spread to the entire population, only dying when it couldn't reach the motorway.
- Planet of Hats: All of the cars the Doctor passes through have obvious themes, be they white décor, Harajuku fashion, hippy nudism, red décor, or stylish fifties Britain.
- Pun: "If it's any consolation, Valerie, right now I'm having kittens."
- Rule of Three: In order to use the fast lane, you have to have three passengers. Lie to the computer, and your car is shut down. In The Teaser, the woman of the American Gothic Couple believes that her husband lying to the computer about there being three people aboard is the reason for their plight, and the entire reason Martha is kidnapped is so that the couple she's with can get to the fast lane.
- Russian Reversal: In New New New New New New New New New New New New New New New York, carjackers steal you.
- Same Character, but Different: The Macra were originally hyperintelligent, spacefaring crab monsters with hypnotic powers. They return forty years later as much bigger crab monsters that are no longer sapient and have no psychic powers. The Doctor claims that they've devolved into dumb animals over billions of years. On the other hand, one reference book holds that the Macra escaped from the New New York Zoo when the power failed, suggesting they were non-sapient to begin with.
- Saw It in a Movie Once: Martha persuades the driver of an air car to shut down all systems (including the much-needed air purifier) so that the large monsters in the poisonous fog won't find them."I saw it on a film. They used to do it in submarines. The trouble is, I can't remember what they did next."
- Selective Obliviousness: Everyone is aware on some level that they've not seen any sign from the government and/or the people on the surface for over 20 years, but it takes some serious prodding from the Doctor before they even start to acknowledge the Elephant in the Living Room.
- Sequel Episode: The final part of the "New Earth" trilogy.
- Series Continuity Error: In "New Earth", the Doctor says the titular planet is in the galaxy M87. In this episode, he says it's 50,000 light-years from the former location of Old Earth. That's a difference of over fifty million light-years, even accounting for the episodes being set five billion years in the future.
- According to Word of God, the concept of an endless traffic jam in a dystopian city is a shoutout to Mega-City One in Judge Dredd, and the man with the bowler hat is based on Max Normal, a supporting character in the comic.
- Sally Calypso is an homage to Swifty Frisko.
- Ma and Pa at the start of the episode are based on the farming couple in the painting American Gothic, both having identical hairstyles, glasses and fashions.
- Apparently, the Doctor's coat was a gift from Janis Joplin.
- Brannigan's appearance was based on "Ratz", the CGI disembodied cat's head that was a "virtual presenter" of CBBC's Live And Kicking in the early 1990s.
- The Slow Path: It's been several decades for Novice Hame and only a year or so for the Doctor since they last met, something Hame points out.
- Song of Prayer: The people stuck in the Motorway sing hymns as a way to keep up their spirits. After the Doctor finally releases the exits, they start singing "Abide With Me", a hymn asking the Lord to come and stay for a time.
- Take That!: To metropolitan traffic jams in general, London in particular. The people on the Motorway think travelling 5 miles in 12 years is making good time.
- Teleportation Sickness: "Rough teleport. Ow."
- Took a Level in Kindness: The Doctor, following his realising how badly he's treated Martha, comes clean with her about Gallifrey.
- Unusually Uninteresting Sight: The people on the underground motorway are disturbingly blasé about the fact that nobody ever gets anywhere, that there's no police, and that the news doesn't do anything special. Martha needs to take a bit of time to adjust to this. This helps to make people never question what happened: the surface got wiped out by a virus.
- Villain Decay: Deliberately invoked. After a few billion years, the Macra devolved into a much less intelligent form, so instead of being invisible puppet masters (like the Silence would be later in New Who), they're just giant crabs living on car fumes.
- You Are Not Alone:
- So says the Face of Boe.
- Everyone in the traffic jam; they're stuck in a dismal situation, but form a genuine community in spite of that. This is most obvious during the hymn scene.Brannigan: You think you know us so well, Doctor. But we're not abandoned. Not while we have each other.