"Martha, Donna. Donna, Martha. Please don't fight. I can't bear fighting."
— The Doctor
Paging the Doctor! When Martha gave the Doctor her old phone
, this is the kind of situation she had in mind.
Since he left, remarkable strides have been made in environmental engineering: in particular ATMOS, a gizmo installed in half the cars on Earth which neutralizes exhaust, with only the tiny side detail of being completely evil and a front for alien murders
. ATMOS is the creation of a teenage genius by the name of Luke Rattigan, who is secretly working for the Sontarans, a warrior race
of militaristic short guys who look a bit like potatoes. (Though the Doctor would like to remind you that to a Sontaran, you
look like a shaved pink weasel-thing.)
Martha and Donna are introduced and, to the Doctor's great relief, get on really well. Martha's now a proper doctor, and with UNIT. The Doctor's a little bit uncomfortable with how well she fits into a military organisation. She retorts that he's the one who got her the job in the first place. He wisely doesn't respond to that.
The Doctor teams up with UNIT, but he doesn't like the way things have changed since the old days, and the reunion is an uneasy one. The Brigadier (now knighted) is a few continents away and unable to help out. Also, Martha is kidnapped by the Sontarans, and they create an evil clone of her.
Meanwhile, Donna goes back home to get another earful from her mum, and to see Wilfred, her dear old grandad, again. The Doctor turns up to fetch her (and meets a delighted Wilfred and a highly apprehensive
mum), just in time for all the ATMOS-equipped cars in the world to begin emitting clouds of poison gas! How can the Doctor stop an alien attack that's occurring in 400 million places at once?
- Absence of Evidence:
Donna: The first thing I noticed is an empty file.
The Doctor: Why, what's inside it? Or, what's not inside it?
Donna: Sick days. There aren't any. Hundreds of people working here and no one's sick. Not one hangover, man flu, sneaky little shopping trip, nothing. Not ever! They don't get ill.
- Affably Evil: Staal is as cordial as a Sontaran even gets towards the two soldiers he meets, up until one of them starts with the height jokes.
- And Starring: Freema Agyeman is credited with an "And".
- Arc Words: Another reference to the Medusa Cascade.
- Berserk Button: Don't say the Sontarans have a weakness, even if they actually do.
- Blue and Orange Morality: The 10th Doctor's notorious loathing of guns at its least justified. The Doctor is openly snotty and dismissive to Colonel Mace all through this and the next episode for no other explained reason than because Mace carries a gun. Mace does nothing this or the next episode to deserve this snottiness.
- Blunt Metaphors Trauma: "Is the temperature significant?"
- The Brigadier: Colonel Mace. The actual Brigadier doesn't appear.
- Broken Record: The factory worker Martha interviews.
- The Bus Came Back: Martha returns for a few episodes.
- Comically Missing the Point: Rattigan calls the Doctor "smarter than the average UNIT grunt". The Doctor gets upset and insists that he not call Ross, his escort, a grunt.
- Continuity Nod:
- To "Voyage of the Damned" (when Donna's grandfather met the Doctor) and "The Runaway Bride" (when Donna's mother met the Doctor).
- And "Dalek" (the "In-tru-da window" pun made by Henry van Statten).
- Donna's mother complaining about Donna disappearing for days.
- The Sontarans mention the Time War, and how the Doctor fought in it. They're upset because they weren't allowed to take part.
- Covered in Gunge: In a distinctly non-humorous manner though.
- Cursed with Awesome: The Sontarans' armour has only one weak point, in the back of their necks. For the Sontarans, retreat is not only dishonourable, but impractical.
- Defeating the Undefeatable: Staal introduces himself as "Staal the Undefeated." The Doctor comments on the nickname's lack of foresight, pointing out that if he was defeated, he would have to be called "Staal the Not-Quite-So-Undefeated-Anymore-But-Never-Mind."
- Ditto Aliens: Though there are minor differences between Staal and Skorr, despite them being clones. Like Luke Rattigan's reaction when Skorr removes his helmet:
Luke Rattigan: How... do you tell each other apart?
General Staal: We say the same of humans.
- Every Car Is a Pinto / Overclocking Attack: Subverted when the ATMOS in the Land Rover suffers from the Logic Bomb, the Doctor and Ross Jenkins run for cover... then the sat nav system fizzles and sparks a little bit.
- Failed Attempt at Drama: Donna says she's going home. The Doctor gives her the big speech about everything he wanted to show her, how she's saved his life, how he was so very grateful for her company and... you're just popping home for a visit, aren't you? Also a stellar example of The Day The Music Lied.
Donna: You dumbo. You great, big, outer space dunce.
- Fate Worse than Death: A Sontaran would rather just shoot a person rather than brainwash them, because "Death has more honour".
- Fun with Acronyms: Both ATMOS and UNIT use the "using letters from within the words" cheat. Although that cheat was somewhat enforced for UNIT — they didn't before, but then the UN started being much more sensitive about its name being used.
- Godwin's Law: One of the UNIT soldiers compares Rattigan's followers to Hitler's youth.
- Grammar Nazi:
- The Doctor:
If only that was possible. The Doctor:
If only that were
possible. [glasses pull]
You can't say "ATMOS system" 'cos it stands for Atmospheric Omission System. So you're saying, "Atmospheric Omission System System
." Do you see, Mr. Conditional Clause?
- Immune to Bullets: Sort of... the Sontarans' new Applied Phlebotinum prevents guns from being fired in their presence. Techno Babble explains that it's because of the bullets' copper jackets. Once UNIT figures that out in the next episode, they switch to a different kind of bullets, and... well, let's just say it doesn't end well for the Sontarans.
- Insufferable Genius: Luke Rattigan. He doesn't like it when someone out-geniuses him. See Grammar Nazi for just one example of it.
- Insult Misfire: Don't call Ross a grunt.
- Magical Computer: The ATMOS reduces emissions and works as a sat-nav system. Also, it can completely take over your car.
- The Missus and the Ex: Subverted; the Doctor attempts to head this off, only for Donna and Martha to jump straight to making fun of him. "Oh, I'd rather you were fighting."
- Motor Mouth: Rattigan, all the time.
- Names to Run Away From Really Fast: Skorr the Bloodbringer.
- Nerd in Evil's Helmet: Luke Rattigan. He seems like a psychopath
- No One Could Survive That: Largely averted. The Sontarans initially think the Doctor is dead, but when they get proof that he's not, they accept it without question. Of course, they know the Doctor, so obviously they'd know how hard it is to kill him.