Gather round, children, it's story time! The tale of "Last Christmas" we'll now tell ... in rhyme!note
'Tis the night before Christmas; that brightest of days! And the Doctor and Clara have parted their ways. Though Gallifrey's gone still and Danny Pink died, each claimed to be fine -- and each of them lied.
Then out on the roof, Clara hears such a clatter, go outside she must and see just what's the matter. And what to her wondering eyes should appear, but a miniature sleigh, and eight tiny reindeer!
(And two comedy elves, one hight Wolf, one hight Ian. But this meter's a wreck, as by now you are seein'.)
It's Santa alright! Though he tries out a fib, the elves and the flying deer botch his ad-lib. So Saint Nick gives the gifts? But he's fake! Are you mad?! "Well, who do you think does it? Your Mum and Dad?!"
Clara's grown up past all those fairy-tales; she stands her ground, giving Santa No Sale. Then up on that roof there's a wonderful sound — the TARDIS! It's back! Is there sense to be found? The Doctor pops out, attack eyebrows half-mast; he wants Clara inside, and no questions asked.
Both the Doctor and Santa Claus know what’s at stake. There's a stand-off; the Doctor leaves Claus in his wake.
The Doctor looks ashen; all portents cast gloom – there’s monsters afoot, and humanity's doom. But there's one great big question, where all our fates rest. "Believe you in Santa?" To which Clara says "Yes."
Cue the main theme! — but longer, in seasonal cheer, and with Nick Frost's name featured since he's guest starring here. It seems the Time Vortex gets snowy sometimes — but anyway, let's just get back to the rhymes.
Now we're out on a base in the freezing North Pole, with a girl who’s about to try taking a stroll through the base’s infirm'ry, with "sleepers" inside: think of them and they'll leave you with no place to hide.
Shona starts walking, trying not to get caught; her boss plays some music to help drown out her thoughts. The song "Merry Christmas Everybody" is played! She'd better keep moving, or else she'll get slayed.
There's three other people inside that base, actually; there’s Professor Albert, and Bellows, and one named Ashley.note And hey, looks like you'd better add on two more. You see, the Doctor and Clara just burst through the door.
"Say, who are those folks lying there in that bed? With those facehugging Dream Crabs clamped around their head?" And they've thought of them now, so the sleepers attack. And the Dream Crabs descend! And they can't drive them back—
But, quick as the jingle of bells on a sleigh, Father Christmas is there, and he's saving the day! But why the hell's Santa Claus coming at all? "Christmas Day! In the North Pole! Who you gonna call?"
The Dream Crabs recede, and the sleepers take pause; they're back in their beds again, ordered by Claus. Everyone's still alive, thanks to his well-timed visit. But that's not the end of the problem, now is it?
See, the Crabs use a certain grim method to feed. They put you to sleep, make you dream, then proceed. So they'll spin you some dreams within some other dreams, THEN they'll suck out your brain. "Mercifully." There's no screams.
So is this all a Crab dream? What's real and what's not? What never existed, and what's been forgot? note It all looks so life-like! It all looks uncanny! Especially when Clara wakes up, and there’s Danny!
But time’s running out. If that chalkboard’s not lying, it has three awful words for her.
Okay, the rhyming is over. You're safe now. Time for tropes:
- Act of True Love: Discussed but ultimately averted. Danny claims that he died to save Clara, not the world, but this is ultimately revealed as just a part of the dream.
- Actor Allusion:
- At the end, Shona wakes up in a living room that looks awfully like Pussy Haven.
- Dan Starkey being cast as an elf. He's played several different Sontarans, aliens who are generally quite short in stature.
- Nick Frost as Santa Claus. In the Doctor Who: Extra for this special, Steven Moffat even said he has "the perfect name" for the role of Santa.
- Adventures in Comaland: When people are taken over by Dream Crabs, this has to happen for them to wake. This happens for much of the episode, with Clara's encounter with Danny being an especially vivid example.
- Aerith and Bob: Wolf and Ian.
- All Just a Dream: Everything in this episode (except for the final scene) is a dream created by the Dream Crabs. However, unlike standard instances of the trope, this episode serves to undo the parting of the Doctor and Clara, and it's also quite dangerous as one individual is Killed Off for Real and the Doctor determines the same could apply to both him and Clara, too.
- And the Adventure Continues: The end of the episode sees Clara back with the Doctor in the TARDIS, ready for more adventures.
- Arbitrary Scepticism: Discussed. The Doctor points out that it's going to be incredibly hard to differentiate between what's a dream and what's reality because he travels in a spaceship disguised as a telephone kiosk, so reality is also ridiculous.
- Arc Words:
- Part way through the episode, the Doctor asks three different times why the scientists are up there, and each of them say It's a Long Story. This becomes a little more meaningful when the Doctor shows that no one seems to be able to explain the story of why they're there. They just claim it's a long story, because it's really a dream so they don't actually know the answer.
- Clara's Series 7 "Impossible Girl" arc is referenced when Old Clara implies that she would have married the Doctor, but "he was impossible."
- Ask a Stupid Question...: The question is usually along the lines of "how can Santa be real?" The answer is "of course, he's not! This is a dream, stupid".
- As You Know: Shona wasn't paying attention to the briefing (see above), so everything has to be explained to her again (and thus the audience).
- Badass Santa: Santa Claus is the visualization of your mind's fight against the Dream Crab's illusion. He can save people with Slinkies and robot toys!
- Bad Santa: Steven Moffat made a point of assuring people that this would be averted and indeed, this Santa is heroic.
- Beardness Protection Program: Santa apparently grew his beard as a disguise. His elves point out that people have gotten wise. (Again with the rhyme, sorry last time. Dang it!)
- Big Bad: The Dream Crabs.
- Big Entrance: Santa does a Big Damn Heroes by blowing a hole in the door, then sending in the tangerines, and slinkies, and toy robots, and armed elves. Then he does the Rearing Horse trope on Rudolf.
- Big Fun: Santa Claus is fat, cuddly, and full of festive cheer. Being played by Nick Frost helps.
- Bigger on the Inside: Allegedly, Santa's sleigh. How else could he fit all those countless presents in?
- Bitch Slap: Clara to the Doctor when he deliberately brings up some painful memories to distract her from the dreamcrabs. (To be fair, he isn't aware of the most triggering aspect, the fact Danny is still dead, at the time.)
- Book Ends: To the discussion of relative age in "Deep Breath". In that episode, Clara appears to have difficulty seeing the Doctor she came to know after he changes appearance and now looks older. In this episode, it's Clara who now looks older, yet the Doctor still sees her as a young woman.
- Brick Joke: A season's worth of the Doctor insulting Clara's appearance is bricked as his "apparent" inability to recognize her as being attractive turns into him now saying she looks no different to him, whatever her age.
- Bring My Brown Pants: Shona says she has to pee before entering the sickbay where the dreamcrabs are, but the others are monitoring her internal signs and know she's just stalling.
- Brown Note: Yet another Moffat example — just thinking of a dreamcrab attracts them to you. In fact, this is just an effect of the dream state the crabs have already put a victim in. If the victim thinks about them, they try to trap the victim in another dream layer to keep them from ever waking up for real before their brains are consumed.
- Call-Back: When Clara first met 11, he asked her if she could fly a plane, because Miss Kizlet, and the Great Intelligence, was crashing one on them. When 12 came back to her as an old lady, she mentions that since he last saw her, she learned how to fly one.
- Celebrity Paradox:
- Professor Albert mentions that the Dream Crabs are a lot like Facehuggers, prompting a discussion about the movie Alien. John Hurt — who plays the War Doctor — and Paul McGann — who plays the Eighth Doctor — feature in Alien and Alien³, respectively.
- Game of Thrones was on Shona's list, despite some crossover between the casts of Who and Thrones — including the actress who plays Shona, although she had yet to make her first appearance on Game of Thrones as the Waif at this point.
- Christmas Elves: Wolf and Ian, Santa's Servile Snarker duo are short and Christmas-themed and such.
- Christmas Miracle:
- The Doctor hasn't missed his chance to travel with Clara again, as Old Clara turns out to be a final dream layer and she is more than happy to join him again.
- Clara being given an opportunity to properly say goodbye to Danny (even if only a dream version) also counts.
- Cloud Cuckoolander: Shona. She's introduced dancing to a Slade song in order to distract herself from the Dream Crabs and spends a great deal of time trying to logically prove that the Santa standing in front of her doesn't exist.
- Continuity Nod:
- The Doctor helping an aged Clara open a Christmas cracker was done not so long ago, but with their roles reversed in the previous Christmas special.
- This isn't the first time someone has pointed out how time flows differently in a dreamnote . In a similar vein, the Doctor also remarks that time travel is possible in dreams.
- This also isn't the first time the Doctor and companion(s) have been trapped in a dream world where they have to figure out if they're still dreaming or have returned to reality.
- The planet where the Doctor wakes up looks similar to where Clara and Twelve shared another illusion.
- The Twelfth Doctor is once again referred to as a "magician", as he referred to himself in "Time Heist".
- Santa says that things are "all a bit dreamy-weamy".
- The Doctor displays a kind of face-blindness where he sees Old Clara as Young Clara. In "The Caretaker", he objected to Danny mistaking him for Clara's dad because he thought he and Clara looked exactly the same age.
- Cuddle Bug: Clara hugs the Doctor, again.
- Deconstruction: The episode partially deconstructs the 'Isolated Base Under Attack' that is a regular Who plotline. It hits all the beats but then turns out to be just a dream, which they're experiencing precisely because it's the sort of story that would feature alien parasites, and is even inspired by Shona having just watched films with that premise.
- Dream Land: Turns out the Arctic base is part of this. It never existed. It was just a scenario created by the Dream Crabs to further ensnare their victims.
- Dream Tells You to Wake Up: Santa's main role in the plot. His presence is a giveaway to the characters that they're still dreaming.
- Dream Weaver: The M.O. of the Dream Crabs* , who put people into a euphoric dream state while their brains are digested. They are incredibly insidious: Once they've got you, they make you think you're not dreaming but in danger of being grabbed by them again. Then they grab you again and put you in another dream layer and try to repeat the process ad infinitum so that even if you manage to free yourself, you're still trapped, which gives them enough time to consume your brain.
- Dream Within a Dream: The final count is five layers of dreaming for the Doctor and Clara!
- Dying Dream: This trope is caused by the Dream Crabs, which slowly drain their victims' brains but stimulate pleasant dreams to keep the victim pacified.
- Ear Worm: Invoked by name as a defence mechanism when Shona dances past the sleepers to "Merry Christmas Everybody".
- Face Hugger: The Dream Crabs suck out your brain through a small hole they make in the skull. Similarities to other works are acknowledged in the episode.
- Fantastic Racism:
- The Elves complain Clara is being Elvist. They also accuse Santa of the same, but he assures them he isn't. They are also briefly concerned whether they can use the word "human" or if it's an N-Word Privileges thing.
- "There's a horror movie called Alien? That's really offensive. No wonder everyone keeps invading you."
- Fantasy Kitchen Sink: Lampshaded by the Doctor when, after they've been rescued by Santa and his elves, he calls attention to the blue police box outside which is a camouflaged spaceship belonging to an alien "magician" who travels in time and space.
- In the opening shot, as the camera pans through Clara's house and upstairs to her bedroom, eagle-eyed viewers will notice that there is the track for a stairlift running up the length of the staircase. This foreshadows the false ending where the Doctor arrives to save Clara from the dream crab, only to discover that it's 62 years since they last saw each other and she is now an old woman. Fortunately this turns out to be yet another dream.
- That scene has the short-term variety as Clara's house doesn't appear to have been redecorated much in the intervening decades, and her television is still a 2010s model.
- When Santa first arrives at the Arctic base, Shona declares, "This is ridiculous! Am I dreaming?", to which the Doctor replies, "Oh, very good." Later the Doctor confirms that they all are having a shared dream, and Santa is part of it.
- Four Is Death: Four "dead" sleepers who turn out to be doubles of the four researchers; Shona, the fourth person to read from the manuals, gets the word "dead" twice. This is subtly lampshaded by the Doctor, whose first word upon realising the pattern is a dramatic "Four..."
- The Fourth Wall Will Not Protect You: The people infected by Dream Crabs end up attacking through the video monitors.
- Freeze-Frame Bonus:
- Shona's "to do" list includes three of the films that directly inspired this episode (and presumably her memories of them contributed to the main dream): Alien, The Thing from Another World, and Miracle on 34th Street. She also planned to marathon Game of Thrones, but that isn't really plot-relevant. Coincidentally, the actress would go on to have a recurring role in the series in 2015, while Maisie Williams would have a recurring role in Series 9 of Doctor Who.
- After Clara kisses the Doctor on the cheek, the pattern of a heart becomes clearly visible in the curtains behind them.
- Fun Personified: Though a snarky, cynical version, Santa's still as jovial as he can get away with.
- Gift of the Magi Plot: Clara lied to the Doctor about Danny surviving so that he would return to Gallifrey. The Doctor lied about finding Gallifrey so that Clara would stay with Danny.
- Good with Numbers: We are told that Clara is very good at solving math problems in her head. Allegedly, anyway: see Writers Cannot Do Math below.
- Hey, That's My Line!: The Doctor gets grumpy when Santa takes over his role as Mr. Exposition. Santa Claus does not get to talk scientifically, nor is he allowed to say "bigger on the inside".
- How Can Santa Deliver All Those Toys?: Santa claims his sleigh is Bigger on the Inside. He also admits he wouldn't be able to deliver all the presents in 24 hours alone, so he has another crew doing half of the chores. However, we only see him in dream layers...
- Implausible Deniability: Santa, at the beginning, in full view of his sleigh, elves and escaped reindeer, tries to bluff Clara.
- Internal Homage:
- The Doctor driving Santa's sleigh and reindeer is reminiscent of a 2009 BBC One ident starring Ten. For that matter, a car alarm being used in Rudolph's own nose resembles the way Ten used a chirping car alarm to lock the TARDIS from the Christmas special of that same year. The scene is also reminiscent of a similar scene (only involving a flying shark) in "A Christmas Carol".
- Old Clara's statement that she never found another man in her life to measure up to the Doctor echoes Sarah Jane Smith's feelings towards the Doctor in "School Reunion". In fact, although the time frame is different, the Doctor expressing regret at not visiting a beloved former companion sooner, and said companion bemoaning the fact she'd gotten old in the meantime, also reflects the Doctor-Sarah Jane reunion in "School Reunion".
- It's a Long Story: Said by all the scientists at the ice base when asked by the Doctor how long they'd been there and what their mission is. Subverted in that it's not a long story at all; there is no story of when they arrived and what their mission is because they're all really dreaming and can't remember their waking lives. The Doctor proves this by asking Clara why they came in the TARDIS to the ice base in the first place and she repeats the scientist's response.
- Jerk with a Heart of Gold: Both the Doctor and Santa fit the type, spending much of the episode in Snark-to-Snark Combat but also being determined to make sure everyone survives the experience.
- Karmic Death: The one one-off character to get himself killed is the one who previously harassed poor Shona during her mission briefing.
- Lotus-Eater Machine: After snaring their victims, the Dream Crabs keep them sedated with a happy dream, but "happy" is not their only setting. First, they create several layers of "realistic" dreams in order to fool their prey into thinking they have "woken up".
- Ludicrous Precision: Santa states exactly how many children he has to deliver presents to in all the world.
- Maybe Magic, Maybe Mundane:
- The final shot of the tangerine, implying that Santa Claus is real or that they're still dreaming. It's even possible that, perhaps, the tangerine was real and influenced his predilection for them.
- Another possible answer is that Santa Claus is real, but the one in this episode was a dream construct. The Doctor has claimed to have met Santa before.
- Meaningful Echo: Clara says she couldn't marry the Doctor because he was "impossible", riffing on her own nickname as the Impossible Girl.
- Men Are the Expendable Gender: Of the four scientists at the Arctic base, the man is the one who dies to prove that the threat is real, while the three women survive to the end. One of the only other major male characters in the story, Danny, is already dead. The Doctor, of course, is not expendable.
- Meta Twist: Apparently Clara was facehugged as an old woman and the Doctor missed out on most of her life before he saves her at the end of the episode. It looks like another case of the modern show's reliance on Diabolus ex Machina twists to forcibly part companions from the Doctor. Then Santa turns up and reveals it's just another dream layer all over again, and the Doctor saves Clara for real while she's still young.
- Moment Killer:
- Clara and Danny Almost Kiss before someone knocks on the door. Given the timing, Clara assumes it's her dad. It's the Doctor, trying to wake Clara up from her Lotus-Eater Machine.
- Old Clara and the Doctor's bittersweet reunion is rudely interrupted by Santa... but neither of them are complaining after.
- Most Wonderful Sound: In-Universe; Clara can't believe how much she missed the sound of the TARDIS.
- No Hugging, No Kissing: Averted; Clara hugs the Doctor in the back of the sleigh. He responds awkwardly at first, but then enjoys the moment. She later gives him a kiss too (on the cheek, of course). (This marks a shift in the Doctor, who had previously adhered to a no hugging rule; hereafter he allows Clara to hug him at will and begins hugging her on occasion, too. Their relationship becomes more affectionate subsequently, as well.)
- Noodle Incident: The Doctor wakes up near a volcano. What he was doing there is never explained. Nor why it closely resembles the volcano seen in a previous dream Clara was in from "Dark Water".
- Not So Above It All: Santa convinces the Doctor to have a go at piloting his sleigh, which he quite enjoys.
- Or Was It a Dream?: Dream Danny starts to sound a lot less like a figment of Clara's memory and more like Danny's spirit itself saying goodbye to Clara when the Doctor convinces her she's not in the real world. One wonders if the Doctor's presence influenced Dream Danny to speak in a way that would give Clara closure, or if this was the real Danny from beyond the grave.
- Pajama-Clad Hero: Clara runs about in her pajamas again, not even changing when she wakes up for real at the end, and runs off for another adventure in the TARDIS.
- Psychic Static: Various methods of "running interference" are attempted to keep the Crabs from reviving. Math problems turn out not to work as well as Shona's rocking out or the Doctor's needling Clara in ignorance that Danny's still dead.
- Puppy-Dog Eyes: For once Clara is on the receiving end, when the Doctor implores her to join him as his companion once more.
- Real Life Writes the Plot: When Jenna Coleman initially signed on to do a second series, she wasn't sure she could work as well with a different Doctor, and asked that her second series would be her last. By the time filming for the series finale "Death in Heaven" began, Jenna found that she so enjoyed working with Peter Capaldi, she asked Moffat if she could at least come back for the Christmas special. During filming of this special, she asked to stay on for another series (after reportedly being lobbied by Capaldi, who didn't want to lose her). This is why both "Death in Heaven" and "Last Christmas" feel like traditional "companion departure" episodes, only to be subverted at literally the last minute; originally they were both written as played straight examples of a companion's departure. Steven Moffat has stated, however, that in both cases he was prepared for (hopefully) Coleman's change of heart. The episode originally was to end with the Doctor and elderly Clara snapping a Christmas cracker; everything after (including the seeming Ass Pull involving Santa) was added after Coleman agreed to stay on. According to an early 2018 interview with Moffat, Coleman didn't agree to stay on until after the readthrough of the episode had taken place.
- Rearing Horse: Santa does this on Rudolph after blowing a hole in the wall for a Big Damn Heroes.
- Santa Claus:
- He's not some alien imposter, either! He's a dream image conjured by the Dream Crab-infested brains, but his entire existence revolves removing the crabs and saving their lives, so he's the real Santa in being a jolly (kinda) giver of gifts (maybe).Shona: You're a dream, that's going to save us?
Santa: Shona, sweetheart, I'm Santa Claus. You may have just defined me.
- The Expanded Universe book The Time Lord Letters reveals that when all is said and done, the Doctor believes him to be really real. He writes Santa a thank-you letter for reuniting him with Clara in reality (having lied to her about not knowing who to thank)... which he leaves stuffed up a chimney.
- He's not some alien imposter, either! He's a dream image conjured by the Dream Crab-infested brains, but his entire existence revolves removing the crabs and saving their lives, so he's the real Santa in being a jolly (kinda) giver of gifts (maybe).
- Santa's Existence Clause: Zigzagged in that Santa is only the dream image of everyone involved and represents their subconscious fighting to keep them alive, but he admits that he exists and is real in their beliefs and hearts. Then that final shot of the tangerine on Clara's windowsill as the TARDIS takes off will keep the audience guessing.
- Shared Dream: Where the Dream Crabs trap their common victims while they suck their victim's brains out. Most of the episode happens in one.
- Ship Tease:
- Elderly Clara has rejected all suitors because there was only one man would could match up to Danny Pink, but it wouldn't have worked because that man was impossible. "Who" could that be? The fact she says this as an old woman who physically looks older than the Doctor lampshades the attitude held by some that the actors were too far apart in age for any sign of shipping to be acceptable (despite the fact the Doctor could be played by a 10 year old and still be immensely older than any of his co-stars).
- After Clara kisses the Doctor on the cheek, a heart becomes visible on the curtains in the background. The fact the camera noticeably shifts perspective in order to line this effect up means this was not accidental.
- The Clara-Danny ship sails one final time as Dream Danny not only says goodbye, he tells her to get on with her life, clearly implying that she mustn't hang onto him. Almost immediately after she "wakes up" from this level of the dream, she becomes more affectionate towards the Doctor, leading to her making the statement (while believing herself to be elderly) that she'd have married the Doctor, and later kissing him on the cheek and agreeing to travel with him once more.
- The episode is named after the famous Christmas-themed pop song by Wham!, though in the song the word "last" means "the one before this", whereas in here it's used as "the final one".
- One of the Arctic base scientists comments that the Dream Crabs are rather like the facehuggers from Alien. The "PURGE" screen toward the beginning of the film (when Shona is entering the infirmary) is remarkably similar to the screen that's shown as the Narcissus launch process starts in Alien. However, they have rather more in common in appearance and habits with the headcrabs in the Half-Life series.
- The setting and tone bring to mind John Carpenter's The Thing (1982) (although that was set in Antarctica). It's confirmed by one of the movies on Shona's list being The Thing From Another World (which was set in the Arctic), the inspiration for Carpenter's movie.
- The layers upon layers of artificial dream state and the presence of outsiders trying to communicate with those trapped inside by leaving written messages and making surreal visits is from Ubik.
- The very idea of the dreamcrabs is very similar to For the Man Who Has Everything, with the dreamcrabs standing in for the equally destructive Black Mercy. This story was also, incidentally, happening in the arctic (within the Fortress of Solitude).
- The Doctor mentions deleting the Arctic base scientists from his mind.
- Mind Screw mystery and horror atmosphere at an isolated polar base ran over by mysterious alien parasites... One of the characters (and then several others) get to do a creepy visit of the base's infirmary. It's almost like a family-friendly version of Penumbra...
- In closed captions one elf's name is The Wolf, though he doesn't appear to display any unusual skills.
- When trying to break out from the dream, Bellows invokes: "God bless us, every one!".
- To Inception with the layered dreams, and realising you're in a dream by asking how you got to your location in the first place.
- More than once the Doctor asks, "Who you gonna call?"... with the answer being Santa Claus.
- Snark-to-Snark Combat: The Doctor and Santa have this dynamic, especially since Santa tends to take the Doctor's usual role away from him.The Doctor: No, no, no, Santa does not do the explanations!
- Speak Ill of the Dead: How the lies from the Series 8 finale ultimately come to light; thinking Danny to be alive, the Doctor figures that slandering him is fair game to get an emotional reaction out of Clara to make her stop thinking about the sleepers, causing her to reveal the truth in her outrage. He later makes amends by referring to Clara's dream recreation of Danny as "brave".
- Standard Snippet: Yet again, Slade's "Merry Christmas Everybody" makes an appearance.
- Steven Ulysses Perhero: Seriously, was there ever a more perfect name for an actor to play Santa Claus than Nick Frost?
- Take That, Audience!: Having Clara briefly seen as an elderly woman — yet the Doctor does not really care about this, saying she will always look the same to him — is a but of take that towards fans who were negative about the age gap between the two actors and any hint of character romance as a result.
- Those Two Guys: Wolf and Ian, Santa's right-hand elves, are interchangeable and here to provide comedy. They are comedy elves!
- This Is Reality:
"It's a lovely story, dear. But it's time to start living in the real world."
- Everyone points out how Santa is impossible, and then he throws it back in their face by proving it's all very real. Then we learn he's only a dream figment and it what was all trying to get them to see they needed help.
- Played for laughs when the elves rubbish Clara's claim that her parents bought her the presents she found under the tree every year at Christmas by scoffing at how ridiculous it is that her parents would suddenly decide to give her a huge amount of presents on the same randomly chosen night every year purely because they "love you so much":
- Titled After the Song: By Wham!.
- Title Drop: "Every Christmas is Last Christmas."
- Trademark Favorite Food: Tangerines. They're Santa's "signature gift" and he gets very annoyed when he's told no-one actually likes them. But he still leaves one on Clara's windowsill after she and the Doctor run away together.
- Trapped-with-Monster Plot: The Doctor, Clara, and the four researchers are stuck at the North Pole with brain-eating alien parasites. Actually, they're stuck in a dream with brain-eating alien parasites who are on their faces at that very moment eating their brains!
- Two Words: Added Emphasis: When Shona refuses to believe that Santa is in the room with them, Santa answers, "I've got three words, Shona, don't make me use them... My Little Pony!"
- Visual Pun: Santa arrives at the Arctic base "[riding] a red-nosed reindeer", á la Slade's "Merry Christmas Everybody", which is heard shortly before.
- Walking in Rhythm: To avoid thinking about the Dream Crabs, Shona has "Merry Xmas Everybody" by Slade played over her headset, and dances past the aliens.
- What Happened to the Mouse?:
- What happened to the crab that succeeded in killing its victim? We never saw the Doctor track it down, so presumably it's still out there somewhere if he ever actually existed.
- Do the other victims ever escape from the last layer of the dream? Were they even real? (It's possible that the last layer of the dream only exists for the Doctor and Clara, especially since it's implied to be a gift from Santa, and the scenes of the others waking up mean they're out of the dream.)
- Who You Gonna Call?: Surrounded by monsters at the North Pole? There is only one person for the job.The Doctor: It's Christmas at the North Pole! Who you gonna call?
- Win to Exit: The only way to break free from the snare of the world of the Dream Crabs is to stop falling asleep. A dream world which is nested into several layers. Otherwise, you wake up back where you started, then reset and repeat. Unless it manages to land a killing blow first.
- Writers Cannot Do Math: Clara's answer to the Doctor asking 304 minus 17 plus 20? 507, which is 200 in excess of the mark. Her math attempts in a later scene are hard to parse, but still only half-right (358x3 = 1,074, and she says 1,774).
- You, Get Me Coffee: The Doctor sends Clara to get the Dream Crab in the sample container, and they engage in some friendly Snark-to-Snark Combat over this trope.