- Adult Fear: Great Britain devolves into a police state and things get increasingly bleak with economic depression. It's made all the worse by the obvious Holocaust parallels at one point. The government sends foreigners away to "labour camps" as they're unable to simply deport them. Donna, while agitated, clearly doesn't grasp the situation in full. Her grandfather, Wilfred, lived through WWII and cries as he watches history repeat itself.
- America Saves the Day: Subverted. They were going to send aid money to help Britain ("God bless America!"), but the Adipose disaster was relocated to America and ended up killing 60 million Americans, so they focused on recovering from that instead.
- And Starring: Billie Piper makes it into the opening credits like this.
- Anyone Can Die: Starting with The Doctor himself! An entire hospital killed with only one survivor, the entirety of London killed when the Titanic crashes and 60 million Americans killed and converted to Adipose. Among the confirmed dead are Martha Jones, Sarah Jane Smith, Gwen Cooper, and Ianto Jones. Jack cannot die, so he was taken to Sontar after the alternate path "The Poison Sky" took.
- As well as Elizabeth II, who had stayed in London during Christmas that year, to "reassure the people it was safe."
- Arc Words:
- The arc words from series 1, Bad Wolf, appear on every sign.
- The bees disappearing.
- We find out what exactly the "something on [Donna's] back" is.
- Bad Future: Without the Doctor there to stop several of the Season's events, the state of the Earth gets worse and worse. South London is flooded with radiation and the whole country starts looking Nazi-ish.
- Berserk Button: Donna is so broken down by the alternate universe that when Rose tells her she's brilliant, she gets angry.
- Best of All Possible Worlds: The alternate universe in this episode is very much a worse place. We have it created when Donna turns right, which causes the Doctor to die at the Thames Barrier when he defeats the Racnoss because Donna wasn't there to stop him. Several contemporary attacks on Earth cause mass casualties, and/or wipe out several of the Doctor's allies (including Martha, whom he never met here). Naturally, Donna set her time-line back on its proper course at the end of the episode.
- Black Box: Blue — the TARDIS. Rose and UNIT don't know how it works but they "scraped off the surface" and jury-rigged a time machine that might work.
- Borrowed Catchphrase: Rose borrows the Doctor's, "I'm sorry... so sorry..."
- Britain Is Only London: Averted, as the latter sections of the story take place in Leeds, in West Yorkshire Oop North.
- Butterfly of Doom: As the title indicates, all Donna does is turn right instead of left. This plunges the world into a dystopian hell.
- Call Back:
- Rose hates being saluted by UNIT,a quirk shared with the Doctor.
- Chekhov's Gun: Wilfred's military service is brought up halfway through the episode. This will be important soon.
- Chekhov's Gunman: The haulage lorry seen passing Donna's car as she waits to decide which way to turn. It's the key to setting things right.
- Continuity Nod:
- The Cloister Bell (the TARDIS' Oh, Crap signal, first heard in "Logopolis") ringing at the end.
- The Trickster is a time-altering villain in The Sarah Jane Adventures.
- Metropolitan Magazine was indeed Sarah Jane's former employer in the classic period (as mentioned in her first story, "The Time Warrior").
- Revisiting the events of "The Runaway Bride", "Smith and Jones", "Voyage of the Damned", "Partners in Crime" and "The Sontaran Strategem"/"The Poison Sky".
- References to Torchwood and The Sarah Jane Adventures.
- The bug on Donna's back is confirmed to be a nod to the spider on Sarah Jane's back from the classic series episode "Planet of the Spiders". The idea of it consuming the time she could have spent is straight from the Weeping Angels.
- Contrived Coincidence: The one in "Partners in Crime" was Lampshaded; The Doctor remarks that out of the whole wide universe, he met Donna twice and by times accidentally.
- Cosy Catastrophe: The middle part, at least, is cosy. Houses are a bit crammed but there's still food, and alcohol and plenty of nice people to sing sea shanties with.
- Crapsack World: Without the Doctor there to do his thing, the world gets worse and worse. Although at least we avoided the Master's reign of terror as without the Doctor's intervention he presumably died at the end of time. Weirdly, Earth doesn't immediately turn into New Pyrovillia with no one to cause the eruption of Vesuvius.
- Death by Despair:
- The Doctor, without Donna, wasn't willing to save himself during the business with the Racnoss. It's implied that the Doctor was feeling so depressed and alone after of the events of the previous episode that he doesn't really care whether he lives or dies, which would explain why he is killed so easily and doesn't regenerate. Meeting Donna eased that loneliness and allowed him to reconnect with the world, which is why Donna was able to snap him back, so he wouldn't die with the Racnoss.
- When the TARDIS finally appears, it's all but outright said she's going the same way.
- Rose basically stands in for the Doctor in this episode, including the dimensional comings and goings, name obfuscation, misplaced enthusiasm, technobabble and hints of an Omniscient Morality License, but it's hard for someone else to pull this off.
- This episode shows what would happen if Doctor Who-level disasters were common in an otherwise familiar human world. It shows the level of human suffering, death, economic depression, and downright boredom that would result if the Doctor weren't there to stop every last one of them, resulting in the aforementioned Crapsack World.
- Distant Reaction Shot: The Titanic crashes into London, resulting in an enormous mushroom cloud visible from Donna's hotel.
- Eagle Land: This episode shows a type 1 because America was going to send 50 million quid in financial aid to help England with its radiation problem.
- Expospeak Gag: "Keep the jacket on at all times, it's insulation against temporal feedback. This will correspond to local time wherever you land. This... is to combat dehydration" (offers ordinary glass of water).
- For Want of a Nail: Donna turns right instead of left, and the whole world — probably the whole universe — changes.
- From Bad to Worse: As bad as the Doctor's universe can be, Donna's World is downright horrifying by comparison. Every scene shows the situation decaying more and more. It's worse still when you consider what the Doctor's would-be companions go through:
- Martha Jones never meets the Doctor, and sacrifices her life to save one man when the Royal Hope Hospital is stolen by the Judoon.
- Sarah Jane Smith is able to resolve the situation at the hospital at the cost of her life — and the lives of her teenaged son, Luke and his friends— allowing the Judoon to return it to Earth.
- Without the Doctor's expertise (or Martha's UNIT connections), Torchwood is forced to deal with the Sontarans, ending with Gwen Cooper and Ianto Jones igniting the atmosphere by blowing up the Sontaran mother-ship from within it.
- Donna Noble. In the year following her father's death she is fired from her job, narrowly dodges the nuclear explosion of London, is shoved into the kitchen of a home housing dozens of people with no money and no identity, only for the United Kingdom to start shipping immigrants to "labour camps" in a desperate attempt to save their own. Oh, and there's this time-travelling blonde stalking her...
- Funny Foreigner: The walking Italian stereotype in the form of the perpetually cheerful Mr. Colasanto... right up until he shares a grim farewell salute with Wilf and drops his façade completely as he and his family are led off to what sounds like their deaths.
- Gilligan Cut: Wilf says America is sending aid money, so everything will be fine soon. Cut to a news report saying that 60,000,000 Americans have been converted to Adipose.
- Heroic BSOD:
- Rose goes blank and silent when Donna says the Doctor has died.Rose: I came so far...
- How the Doctor died in the first place — after killing all the Racnoss and without Donna to snap him out of it, he either left it too late to get away from the flood or was so despondant with Rose gone, that he just let himself drown
- Rose goes blank and silent when Donna says the Doctor has died.
- Heroic Sacrifice:
- Martha gave her oxygen tank to her colleague.
- Sarah Jane and co. died stopping the malfunctioning MRI.
- Gwen and Ianto died exploding the Sontaran ship.
- Donna jumped in front of a lorry to cause a pile-up so her past self will turn left and undo all the damage.
- In Spite of a Nail: It doesn't matter whether Donna turns left because she's being stubborn or because there's a traffic pile-up, or that she has a mysterious dead doppelgänger.
- It Began with a Twist of Fate: It's revealed that the only reason Donna Noble ever got embroiled in the Doctor's life at all was because one day, she turned left, not right. Good thing she did, too; that same episode reveals that turning right led to the Doctor's death, the nuclear destruction of London, and the end of reality itself. Yikes.
- It's a Wonderful Plot: This episode demonstrates that Donna was correct when she said that The Doctor needed someone to stop him. Without her, he drowns in the Thames. To underscore this point, the point of incident takes place before Christmas.
- Kick the Dog: Donna's mother calling her a disappointment.
- Kill 'em All: Doctor, Martha, Sarah Jane, Maria, Clyde, Luke, Gwen, Ianto. With Donna and Rose the main characters of the episode and Jack immortal and Owen and Tosh already dead, that's every character that's ever had billing in all three series. Since this all gets reversed by the end of the episode, it's also an example of the Second Law of Metafictional Thermodynamics.
- Killed Off for Real: UNIT confirms that The Doctor is dead and presume that whatever killed him happened too quickly for him to regenerate, and thus he's permanently dead. In this parallel universe at least; if he were dead in every universe then he would be Deader Than Dead.
- Late-Arrival Spoiler: When the Sontarans attack, Rose spoils the series 2 finale of Torchwood by only mentioning Ianto, Gwen and Jack.
- Leaning on the Fourth Wall: After the line about the stars going out, Donna looks straight at the camera and says, "I'm ready." Cut to Rose, right there.
- Limited Wardrobe: Donna asks why Rose is always wearing the same clothes; presumably Rose is doing all this time-hopping in the same day, like in "The Girl in the Fireplace".
- Make Wrong What Once Went Right: The Trickster's beetle screws up time so Rose sends Donna back to make it right again.
- The Man Behind the Man: The fortune teller and the beetle are working for the Trickster.
- Mind Screw: Once you get over the disaster and the sadness and the temporal weirdness and try to work out what the hell just happened, your eyes cross.
- Missing the Good Stuff: Donna missed the crash of the Titanic, bringing the total to three London-based disasters she's somehow managed to miss.
- Mood Whiplash: One minute, Donna and her mother are having a truly depressing conversation about their current condition, then Donna hears singing from the next room and goes to yell at them, until she sees Wilfred's joining. Smash Cut to the entire family singing along with their housemates, the first time they've been happy for a long time, the next they hear gunfire from outside.
- A Nazi by Any Other Name: The "England for the English" law, passed by the new emergency Government involves labor camps for minorities.
- Oh, Crap:
- The Doctor from the second Donna mentions that Rose was blonde. Then it gets worse not once, but twice.
- The Cloister Bell rings. It only ever rings when something really bad is going to happen.
- Even before Donna goes back in time, the conversation with Rose where Donna realises that dead is dead:Rose: Good luck.
Donna: I'm ready.
Rose: One minute past ten.
Donna: 'Cos I understand now. You said I was gonna die, but... you mean this whole world. It's gonna blink out of existence. But that's not dying, 'cos a better world takes its place. The Doctor's world! And I'm still alive!
(Rose doesn't answer)
Donna: That's right. Isn't it? I don't die, if I change things, I don't die, that's... that's right, isn't it?
Rose remains silent until...
Rose: I'm sorry.
- The look on Donna's face (and her immediate reaction) mirrors just about every fan watching the episode.
- Planet of Hats: Shan Shen is basically Friendly Local Chinatown on a planet wide scale. The banners, the fortune tellers, the ethnicity of its people, etc.
- Prophecy Twist: If Donna goes with Rose, she will die. She does, sort of, in that the future-version of the alternate Donna dies to prevent the past-version of the alternate Donna from turning right. Donna Noble prime is still alright and dandy. Although the next episode suggests that wasn't it, and Donna is still a bad insurance risk.
- Putting on the Reich: The British government seems to do this, if Wilfred's comments when the Colasantos are taken away are to be believed:Wilf: Labour camps. That's what they called them last time.
Donna: ...what d'you mean?
Wilf: It's happening again.
Donna: What is?
::Cut to the perpetually optimistic Mr Colasanto, who is hugging his wife and breaking down in tears as they are hauled away.note
- Real Life Writes the Plot: The reason Donna doesn't have anything to make her cling to her life in this alternative universe is that Russell T Davies gave up on his original idea of her having children during the middle of this havoc, since she already had a good marriage and children in Steven Moffat's episode, which would air two weeks earlier. Also, the Doctor hints that there's something strange about the multiple alternative universes popping up around her because Russell and Steven were both using the same idea. It was worked into the plot after they exchanged e-mails about the episodes.
- Reset Button: By preventing herself from turning right when she originally turned left, Donna prevented this episode from taking place. Except there is still fall out; Rose uses the incident to pass on a warning to The Doctor.
- Shout-Out: The whole Just Before the End meets Kitchen Sink Drama feel hearkens back to The War Game and Davies's own The Second Coming
- The Stars Are Going Out: Wilfred sees the stars going out when he can no longer see Orion's Belt.
- Stepford Smiler: Rocco puts on his usual cheer as his entire family is being set off to a "labor camp".
- Tempting Fate: When the ATMOS starts poisoning the sky, Donna asks Rose how it could get worse. She finds out very soon.
- Took a Level in Jerkass: It's made extremely clear that Donna's mellowing out was due to the Doctor — she's just as stubborn and obnoxious as she was in the Christmas special.
- What If?: when Donna came to a certain intersection, she made a right hand turn to a photocopier business instead of turning left, to work at a security firm?
- What the Hell Is That Accent?: Billie Piper apparently lost the accent she had used as Rose in Series 1 and 2, so she speaks with a noticeable lisp. She also has a pronounced overbite that she never used to have, mildly affecting her speech (and possibly causing the lisp).
- Wide-Eyed Idealist: Donna is laughably naive in this episode, and severely overestimates how necessary secretaries are.
- Wistful Amnesia: Kinda-sorta. When Donna denies knowing anything about the Doctor, she's visibly crying.
- You Are Better Than You Think You Are: Rose and the Doctor tell Donna she's brilliant, even though she insists she isn't.
- You Look Familiar: Chipo Chung, who plays the Fortune Teller, played Chantho in Utopia.