After a two year absence, Sherlock returns to London at his brother Mycroft's request. There has been much speculation since his "death" with many having always believed he was alive and well. While many rejoice, one who doesn't take his return well is John Watson who, after grieving the loss of his friend, moved on with his life both professionally and personally. He's upset that his friend didn't trust him enough to tell him just what he was doing. He's also engaged to Mary Morstan. While he tries to get his old friend onside, Sherlock also has to deal with the main reason Mycroft wanted him back: they have credible evidence that there is to be a major terrorist attack in London.
- Actor Allusion:
- Sherlock's French accent when posing as a waiter may be a reference to Cabin Pressure (in which Benedict Cumberbatch also stars and had previously done an episode-long Shout-Out to Sherlock).
- The bomb-Parliament-via-the-Underground plot is a shout-out to V for Vendetta, which also starred Rupert Graves as a cop.
- Adaptational Wimp: Moran. In the books, he was a crack marksman and a badass Great White Hunter who spent time as a big game hunter in India, and served Moriarty as his chief assassin. Here, he's a Member of Parliament who merely serves as The Man Behind the Man to the terrorist group (with some unknown party behind him), preferring to operate from behind the scenes.
- Always Someone Better: Mycroft to Sherlock.
- Amazingly Embarrassing Parents: Subverted. Sherlock and Mycroft are mortified by their parents, but they're the most down-to-earth couple you could meet (albeit with Hidden Depths). The Holmes brothers, on the other hand...
- Anger Born of Worry: John punches, strangles and headbutts Sherlock for pretending to be dead for the last two years.
- Are You Pondering What I'm Pondering?: A funny moment between Sherlock and Molly when he tries to make her take John's place:Sherlock: Molly...Would you...? Would you like to...
Molly: Have dinner?
Sherlock: Solve crimes?
- Ascended Meme:
- "I don't shave for Sherlock Holmes" also became one.
- As Himself: Anderson's theory of how Sherlock did it involves Derren Brown hypnotising John while Sherlock sets the scene. Lestrade picks this out as a particularly ridiculous detail. Anybody who's seen Derren's shows will instantly recognize his usual methods, including many of the words (e.g. "right there in the centre of your head").
- The Atoner: Anderson has become one thanks to his guilt over his suspicions about Sherlock.
- Aw, Look! They Really Do Love Each Other: Lestrade greets Sherlock's return with a big hug.
- Also, Sherlock and Mycroft.
- Bait-and-Switch: Mycroft mentions learning Serbian in two hours. Sherlock tells him that he's slipping.
- Big Damn Heroes: Sherlock saving John's life by physically getting into and pulling him out of a bonfire.
- Big Damn Kiss: Between Sherlock and Molly (in Anderson's Imagine Spot) and between Sherlock and Moriarty (in an Empty Hearse member's Imagine Spot).
- Bookends: The main story starts and ends in The London Underground.
- Cassandra Truth: Sherlock reveals to Anderson the details of how he faked his death. Anderson, who has been obsessing with this for two years and has even formed a fan club and a number of his own theories (involving such things as Latex Perfection, bungee jumping, and Derren Brown), refuses to believe him. Then again, Sherlock could have made it up just for fun.
- Casting Gag: Sherlock's parents are Benedict Cumberbatch's actual parents, and John's girlfriend Mary is Martin Freeman's (then) real-life partner Amanda Abbington.
- Chekhov's Gun: The squash ball Sherlock was bouncing in Barts in "The Reichenbach Fall". Revealed in this episode to have been part of Sherlock's plan to fake his death, namely by lodging the ball in his armpit to temporarily stop his pulse. Possibly.
- Cliffhanger Copout: Subverted. The episode appears to show several glaring continuity changes from the end of "The Reichenbach Fall", where Sherlock jumps from a rooftop to his apparent death (even featuring a closeup of his blood-stained corpse). When the scene is revisited, Sherlock is very obviously attached to an elastic cord that has magically appeared out of nowhere, and what appeared to be Sherlock's corpse was really that of Jim Moriarty in a latex mask (brushing aside the very noticeable height difference between the two men). However, it's then revealed that this retelling is all just Anderson's crackpot theory.
- Clothes Make the Legend: After his hiatus (and character development), Sherlock has embraced the deerstalker hat as part of his 'public identity', donning it before addressing the press. Also, he seems attached to his coat, asking Mycroft "Where is it?" before Anthea walks in with the coat, at which Sherlock smiles and allows her to put it on him.
- Coincidental Broadcast: During the meeting of The Empty Hearse fan club, TV news are running in the background. Suddenly the news ticker announces "Hat detective alive".
- Continuity Nod:
- When John first sees Sherlock again after 2 years, his immediate reaction is to punch him, multiple times. His punches land on his mouth and nose. In A Scandal In Belgravia Irene mentions 'Someone loves you. If I had to punch that face I'd avoid your nose and teeth too.'
- Sherlock still doesn't know Lestrade's first name.Sherlock: You've been letting things slide, Graham.
Sherlock: ... Greg.
- Sherlock's response to Mycroft saying he isn't lonely, is what Mycroft responded when Sherlock said "Sex doesn't alarm me" in A Scandal In Belgravia.Mycroft: I'm not lonely Sherlock.
Sherlock: How would you know?
- When Sherlock attempts to ask Molly out, she asks if Sherlock got the chip shop owner off a murder charge. Sherlock had done just that with Angelo, as Sherlock stated to John in A Study In Pink.
- Crazy-Prepared: Sherlock calculated thirteen possible outcomes when he met with Moriarty on the rooftop. The only one he didn't foresee was Moriarty killing himself.
- Operation Lazarus is an extremely pre-prepared gambit for the unlikely event that Sherlock has to fake his own death.
- Curse Cut Short: Subverted repeatedly in which a scene of someone (usually Sherlock) beginning to swear is cut off by a cut to a scene of John in his surgery... saying something innocuous that nevertheless completes the curse.Mrs Hudson: [regarding Sherlock's reappearance after two years] What did [John] say?
[cut to John in his surgery]
John: [to patient] Cough.
- Death Glare: John as several of these before attacking Sherlock after the latter is able to reveal he's alive.
- Mycroft has one when he says "I am the smart one" after Sherlock mocks him.
- Death Seeker: Sherlock notes in his story that, apart from wanting to cut off his greatest option, Moriarty just plain had a death wish, which he should have realised from how cavalier he was about Sherlock threatening to set off a bomb in their first encounter (and his general attitude of finding life and people so intolerably boring).
- Didn't See That Coming: Sherlock admits, that he didn't know Moriarty would be desperate enough to kill himself to destroy Sherlock.
- Does This Remind You of Anything?: The plot to use a tube carriage to blow up Westminster Palace? Rather like V for Vendetta. And on Guy Fawkes night, no less.
- Early-Bird Cameo: At the fan club meeting, when they are watching the news, in the panel under the reporter you can read "Magnussen summoned in Parliament...". Magnussen would later become the antagonist in "His Last Vow".
- Emerging from the Shadows: How Sherlock reveals himself to Lestrade at the parkade.
- Exact Words: Sherlock wasn't lying when he said he didn't know how to defuse a bomb. He just happened to know that bombs usually have "off" switches.
- It's not an underground network, it's an Underground network.
- Failed a Spot Check: John, multiple times, completely fails to notice that Sherlock is standing right next to him. Sherlock himself is rather annoyed at his complete inability to recognise his increasingly unsubtle hints and see through the particularly atrocious disguise he's wearing.
- Sherlock, in his turn, somehow fails to notice that John is furious enough to attack him. And he doesn't notice — or maybe doesn't care — that he's interrupting a proposal.
- Sherlock fails to notice that seven train carriages left one train station, but only six arrived at the next. He does notice later when he and John review the footage again.
- Sherlock didn't spot Molly's engagement ring until he tried to ask her out.
- Fair Play Whodunit: As Sherlock points out, the clues have been staring him in the face all along. And the audience too.
- Fate Worse than Death: As far as Mycroft is concerned, this is the Les Misérables matinee with his parents.
- Final Speech: Invoked, played straight AND THEN subverted; when Sherlock pretends to be unable to defuse the bomb, John calls him out on it and says he's just bluffing to get John to say something nice. Upon Sherlock's denial, John promptly goes into this mode himself, saying Sherlock was the best and that he was forgiven for faking his death. As John prepares for the big kaboom, he's interrupted by Sherlock's giggling, and it's revealed that Sherlock stopped the bomb but neglected to inform John precisely to get John to forgive him in their 'last moments'.
- Foreshadowing: The boys going "Penny for the guy" outside 221B when John first approaches it. He later ends up kidnapped and put in a bonfire like a Guy Fawkes effigy.
- Freeze-Frame Bonus: All of Sherlock's deductions about Mary.
- Magnussen is mentioned to be summoned before Parliament in a BBC newscroll.
- The fact that the activation code for Moran's bomb is that day's date is also easy to miss.
- The newspaper Sherlock is reading while he is in Mycroft's office has the headline "Skeleton Mystery". As in the one Sherlock later solves with Molly.
- Frying Pan of Doom: Downplayed. Mrs Hudson arms herself with a frying pan when she sees a Sinister Silhouette approaching her door. Turns out it was Sherlock returning.
- The Glomp: Lestrade's second reaction to Holmes appearing alive and well in front of him. His first: [long Beat] "Ooh, you bastard!"
- Greater-Scope Villain: Watson and Sherlock wonder who it was who put Moran up to this, with Sherlock saying he doesn't like not knowing. Cue a cut to a shady man with glasses watching a video of Sherlock rescuing Watson from the bonfire.
- Has a Type: Molly's new boyfriend dresses exactly like Sherlock, and looks rather like him as well. This is obviously a coincidence.
- Hero Stole My Bike: Sherlock commandeers a random stranger's motorbike on the premise of it being the fastest means of transport to save John.
- He's Just Hiding!: In universe the Empty Hearse all believe that Sherlock survived his fall and was doing this.
- Homage: Mark Gatiss was inspired to use the London Underground as a setting by the Doctor Who serial "The Web of Fear", which is primarily set in the Underground after London is evacuated due to the spread of a deadly web-like fungus via the Tube network.
- I Have Your Wife: The new Big Bad kidnaps Watson. At the end of the episode, John lampshades why it was him and not Sherlock, since he'd had already revealed he was still alive and was on the verge of solving the terrorist conspiracy, making him far more of a target.
- Imagine Spot: The false explanations of how Sherlock survived, and the vision of what will happen if Moran's plot succeeds.
- Ironic Echo: Sherlock throws Mycroft's 'How would you know?' from Scandal back at him.
- Irony: Sherlock actually mocks Mycroft for being lonely, for a change.
- It's All About Me: Sherlock, of course. His reaction when told that after two years, Watson may have moved on from his life?Sherlock: What life? I've been away.
- Just Train Wrong: The Underground trains depicted in several sequences are the wrong size (small-size Jubilee Line trains for the full-size District Line). The bomb carriage is actually Bigger on the Inside, and must have property-changing abilities, since it apparently starts as a Jubilee Line 1996 Stock car, becomes a car of Bakerloo Line 1972 stock when Sherlock and John find it, and its interior is that of a District Line D Stock car.
- Kleptomaniac Hero: Sherlock, to create a waiter disguise in the restaurant steals a bow tie, a menu, and mascara to draw a fake moustache.
- Latex Perfection: One of Anderson's theories for Sherlock's survival involves Moriarty's body being with a latex mask of Sherlock's face good enough to fool John, and also features Derren Brown hypnotizing John to sleep.
- Leaning on the Fourth Wall: When Sherlock is going outside to speak to the press, John says that he loves "being Sherlock Holmes." Sherlock responds, "I don't even know what that's supposed to mean."
- Lonely at the Top: This episode makes it especially clear that for all Mycroft's intellect and power, he really is a lonely person.
- Magic Countdown: The bomb counter starts counting down from 2:30 min but it takes 3:15 min until John has finished his Not-So-Final Confession. Justified, as Sherlock had managed to turn off the bomb after 1 min via off switch.
- Mirror Scare: Early on in the hospital locker room Sherlock appears in Molly's mirror which gives her a big surprise.
- Mistaken for an Imposter: An eccentric DVD-seller comes into John's surgery and John thinks he's actually Sherlock in disguise. He isn't, but the scene pays homage to a scene in the equivalent short story, where Holmes turns up at Watson's house disguised as an eccentric bookseller.
- Mundane Solution: Sherlock doesn't know how to disarm a bomb, but does know that they must have an off-switch. Problem solved.
- My God, What Have I Done?: Anderson is clearly in shock about his role in Sherlock's downfall, as he tries to make up for it. He gets a stronger dose of this when Sherlock delivers his "The Reason You Suck" Speech.
- Mythology Gag:
- The main villain of the episode is Lord Moran, as in Colonel Sebastian Moran. This episode that ends the Mofftiss version of the Great Hiatus is "The Empty Hearse", as in "The Adventure of the Empty House".
- The "skip code" cipher in the text message first appeared in "The Adventure of the Gloria Scott". The phrase "John or James?" in said text message is a reference to the confusion about Watson's first name, which started when Sir Arthur accidentally had Mary address him as "James" in "The Man with the Twisted Lip".
- The old DVD seller's regular doctor is Dr Verner, to whom Watson sold his practice in the original stories to move back into Baker Street with Sherlock.
- John mistaking the old DVD seller for Sherlock also references Holmes' disguise as an old book collector in "The Empty House." Even the DVD titles are the same as the books Holmes was carrying.
- This also references the Basil Rathbone film The Spider Woman, where Watson also mistakes a bearded man as Sherlock in disguise, as he already knows that Sherlock is alive.
- There is an allusion to The Giant Rat of Sumatra, an off-page escapade mentioned in "The Adventure of the Sussex Vampire" in 1924.
- Sherlock finds out that a man impersonated his step-daughter's boyfriend, as in "A Case of Identity".
- Baron Maupertuis is briefly mentioned as a member of the Moriarty organisation; he was the villain of an untold case mentioned in "The Adventure of the Reigate Squires".
- The disused station is in the fictional Sumatra Street, enabling Sherlock to call Moran "The giant rat of Sumatra Street". The Giant Rat of Sumatra is one of the more famous untold cases in the canon, "a tale for which the world is not yet prepared". In addition, Maupertuis was involved with "the Netherland-Sumatra Company".
- Not So Above It All: Sherlock pushing his parents out of 221B the second John arrives and then trying to be totally casual about it afterwards.
- Not-So-Final Confession: First lampshaded by John when death by bomb explosion is imminent. But then he actually falls for it and brings himself to complement Sherlock."No, no, no, no, no, no, this is a trick. Another one of your bloody tricks. You're just trying to make me say something nice. Not this time."
(but moments later)
"You were the best and the wisest man that I have ever known."
[cue the bomb not going off and Sherlock having a good laugh]
- Offscreen Moment of Awesome: Sherlock, "...spent the last two years dismantling Moriarty's network."
- Oh, Crap!: Sherlock gets one in the restaurant after revealing himself to John, and suddenly realizing how pissed off John is that Sherlock never told him he was alive.
- Once More, with Clarity!: Sherlock eventually explains the events of "The Reichenbach Fall", where it is shown to actually be a con by Sherlock and Mycroft to get their hands on Moriarty's criminal network ... Maybe. We're left in limbo as to whether Sherlock is actually telling the truth, or if this is just another false explanation.
- According to Word of God, it's the truth ... if you trust Steven Moffat, that is.
- Given that Sherlock disappears into thin air leaving Philip to cackle madly and tear down his wall of theories, we're left into limbo as to whether he was ever there, or if Philip went crazy a bit earlier than we thought.
- Out-Gambitted: At the end of "The Reichenbach Fall", it appears that Moriarty outplayed both Holmes brothers, but it's revealed that he was the Unwitting Pawn all along as Sherlock explains what actually happened.
- Paper-Thin Disguise: Sherlock's disguise that he uses when surprising John consists of him taking a bow-tie and a pair of glasses from restaurant patrons, scribbling on a fake moustache with eyeliner, and a questionable French accent. It works.
- Power Incontinence: Sherlock tosses Mycroft a hat a client left, asking him to do deductions about his owner. Mycroft refuses, but before he realises he's already started describing the owner.
- Pstandard Psychic Pstance: Sherlock takes this pose when trying to think of a way to defuse the bomb in the subway car.
- Pursued Protagonist: Sherlock at the start of the episode, being pursued by soldiers and a helicopter with a thermal camera through a forest.
- The Quiet One: Moran hardly makes a sound, despite being the primary villain of the episode.
- A Rare Sentence: This exchange:Sherlock: No, I prefer my doctors clean-shaven.
John: That's not a sentence you hear every day.
- And later:John: I don't shave for Sherlock Holmes.
Mary: You should put that on a t-shirt.
- And later:
- "Rashomon"-Style: The episode flashes back to multiple different theories on how Sherlock survived the end of "The Reichenbach Fall".
- "The Reason You Suck" Speech: Sherlock calmly explains to Anderson exactly what he caused to happen, leading the latter to break down.
- Replacement Goldfish: Molly Hooper's new boyfriend has a similar facial structure and build to Sherlock, even wearing a coat and scarf similar to Sherlock's own. She's apparently the only one completely oblivious to the resemblance.
- Molly serves as one temporarily, when Watson doesn't want to continue fighting crime with Sherlock, and Sherlock accidentally calls her John a couple of times as he keeps hearing his voice.
- The Reveal: Lord Moran arranged his "disappearance" by detaching a subway car in the London Underground and using it to hide his explosives. Also, Sherlock faked his death by falling on a hidden inflatable mattress, temporarily stopping his pulse with a squash ball, and paying members of his homeless network to pose as paramedics.
- Room Full of Crazy: The walls in Anderson's flat are plastered with news clips, notes and fan drawings connected by strings, as he's gone a little insane due to guilt for being one of those responsible for Sherlock's (supposed) death.
- Rule of Funny: Sherlock somehow completely fails to twig that John is extremely — not mildly — furious with him for not contacting him while he was playing dead. As a result, he keeps getting attacked by him when he says the wrong thing. note
- Rule of Threes:
- Sherlock gets strangled, punched and headbutted as John takes his return rather... badly, shall we say. John gets thrown out every time he assaults Sherlock, going from a posh Marylebone restaurant to a cheap café and eventually a kebab shop. Amusingly, Mary seems to be a mixture of thrilled and amused as she tags after the two, considering that Sherlock interrupted John's proposal.
- Also done in the scene intercutting John and Sherlock at work, see Twisted Echo Cut. John inadvertently completes Sherlock's obscenities thrice.
- The audience is given three different explanations for how Sherlock could have survived his fall off the roof, and Sherlock attempts to apologize to John three times—first at the restaurant(s), and then in 221 B after John has been rescued from the bonfire, and finally in the train car after Sherlock has disabled the bomb.
- Say My Name: Sherlock and Mary cry John's name several times each while rescuing John from inside a bonfire.
- Sherlock Scan: Sherlock and Mycroft have a Scan-off with a hat left behind by one of Sherlock's clients, volleying deductions back and forth until Sherlock runs out of fresh details to analyse. However, Sherlock offers an insight into the subject's social isolation overlooked by Mycroft, who cannot perceive loneliness in himself or in others. Non-verifiable deduction so Sherlock loses the battle... but he wins the broader war by completely flummoxing Mycroft.
- Shipper on Deck: There's a fangirl in the Empty Hearse who wanted to believe that Sherlock and Moriarty were in love.
- When Sherlock is standing on the rooftop looking out at London, it's in the exact same spot as Daniel Craig at the end of Skyfall; the skyline and camera angles match perfectly.
- Sherlock inviting Molly to solve crimes with him in John's absence is reminiscent of the Doctor taking in a new companion.
- Also to Elementary, where Sherlock's Watson is female.
- The Underground car that disappears between stations is reminiscent of the Conan Doyle story "The Lost Special", in which a well-organised criminal mastermind engineers the disappearance of an entire train.
- Sherlock's visualisation of how the bomb would explode Parliament through the air vents are similar to the visualisation of how the gas would poison Parliament through the air vents in Sherlock Holmes (2009).
- Likewise the way he creates a costume by plucking various elements from his surroundings as he walks through the restaurant is similar to how Holmes puts together his beggar's outfit while tailing Irene Adler in the same movie.
- The appearance of Derren Brown being involved in an unusual event may be due to his recent mention in the Doctor Who 50th-anniversary special, "The Day of the Doctor" as UNIT's go-to explanation for strange activity.
- Mary's comment "You should put that on a T-shirt" (in response to John claiming "I don't shave for Sherlock Holmes") is very reminiscent of the line from the Doctor Who episode "Blink", "The angels have the phone box. I've got that on a T-shirt!" In both cases, shirts bearing these captions have indeed been sold on specialist websites.
- A The Book of Mormon poster is seen in a tube station.
- Smart People Play Chess: Subverted. The camera angle makes it appear that Sherlock and Mycroft are in the depths of a game. Then the buzzer goes, the shot changes, and we see they are playing the age-old children's game Operation, with the chessboard on the other table in the background.
- Soundtrack Dissonance: Some rather upbeat Latin music is playing as John tackles Sherlock to the ground and strangles him.
- The song is "Dónde Estás Yolanda" by the band Pink Martini. The Spanish lyrics translate to: "Where are you Yolanda? What happened? I looked for you but you weren't there."
- Stealth Hi/Bye: Sherlock pulls one on Graham to announce that he's alive. Er, Greg.
- The Stinger: We find out the identity of the man who ordered the attack on John — Magnussen.
- Straw Fan: The episode begins with a somewhat ludicrous explanation of how Sherlock survived the previous season's Cliffhanger... before it is revealed the story was created by Anderson, who has set up a club for fans of Sherlock Holmes who believe he is still alive. Later we see a fairly creepy moment between Sherlock and Moriarty that turns out to be a member's Slash Fic. When Sherlock finally does explain to Anderson how he did it, Anderson complains, "Not how I would have done it", listing all the internal inconsistencies in the explanation and refusing to believe him.
- String Theory: Present in Anderson's flat.
- Suckiness Is Painful:Mycroft ("Do You Hear the People Sing" blares over phone) Sherlock, please. I beg of you. You can take over at the interval.
Sherlock: Oh, I'm sorry, brother dear, but you made a promise. There's nothing I can do to help.
Mycroft: But you don't understand the pain of it the horror! (Sherlock hangs up)
- Super Cell Reception: Properly averted. As soon as Sherlock and John head into the Underground maintenance tunnel, there's no more service on John's mobile.
- Surprisingly Realistic Outcome: Sherlock assumes he can pop back into Watson's life and be welcomed like old times. It takes him a while to grasp how absolutely furious Watson is about Sherlock putting him through the agony of his "death" and the aftermath and not ready to forgive him in the least.
- It turns out that Moriarty's entire "Richard Brook" story fell apart fast once Scotland Yard looked into it and realized they couldn't find anyone who had actually worked with Brook on all the supposed TV shows and movies he did and that the identity was made up to frame Sherlock.
- Take That, Audience!: Anderson's "Sherlock Fan Club" takes potshots at multiple Sherlock fandoms.
- One of the members comes up with an explanation for how Sherlock survived, with Sherlock and Moriarty making out at the end. Anderson promptly dismisses this as absurd.
- Anderson comments that how Sherlock survived is actually "rather disappointing", and then quite possibly loses his mind.
- Sherlock's first scenario for surviving the fall (jumping into a nearby laundry van) which was quickly shot down (the angle was too steep) was actually suggested to Una Stubbs by the hosts of ''The One Show.''
- Time-Passage Beard: To depict the two years having passed since the end of Season 2.
- Sherlock has a full beard at the start when kept a prisoner in Eastern Europe. He has it all shaved off by a barber upon his rescue.
- John now wears a moustache.
- Anderson has grown a full beard too.
- Title Drop: Anderson's Sherlock fangroup is called "The Empty Hearse".
- Tranquil Fury: John goes into this when Sherlock reveals himself in the restaurant, due to Anger Born of Worry. Sherlock even realizes he's in big trouble.
- Truth in Television:
- There really are hidden stations in the Underground, as well as other tube systems left off public maps.
- Some terrorists' bombs — such as the IRA — really do have an 'off' switch. Mercury switches are commonly used as anti-handling devices, and transporting them can complete the circuit early. The idea that all terrorist bombs have this, however, is pushing it a bit.
- Twisted Echo Cut: Hilariously done by intercutting scenes of John dealing with his patients and Sherlock dealing with his humdrum clients. Sherlock's scenes end with some kind of obscenity implied... which then cuts to John seemingly completing said obscenity. Also done as a Rule of Threes:
- Sherlock learns from a client that her email pen-pal has broken it off with her and that she's now too heartbroken to date anyone else; he realises (in a Shout-Out to the original Holmes story "A Case of Identity") that the woman's stepfather has been posing as her online boyfriend in order to break her heart and ensure that she won't leave the household and take her income with her:Sherlock: Mr Windibank, you are a complete and utter-
[cut to John Watson in his doctor's room]
John: [holding up an empty urine sample jar to a patient] Pisspot.
- Before that, Mrs Hudson asked Sherlock to talk to John.
- Sherlock learns from a client that her email pen-pal has broken it off with her and that she's now too heartbroken to date anyone else; he realises (in a Shout-Out to the original Holmes story "A Case of Identity") that the woman's stepfather has been posing as her online boyfriend in order to break her heart and ensure that she won't leave the household and take her income with her:
- Unreliable Narrator: The show itself is this for the first two explanations of how Sherlock survived the fall, only revealing at the end that they are actually outlandish theories by members of The Empty Hearse. Whether or not Sherlock is this when it comes to the third explanation is left up in the air.
- Unpleasable Fanbase: In-universe, Anderson is clearly disappointed with Sherlock's explanation of how he escaped death.
- The Unreveal: Played to the hilt, with a group of fanatic Sherlock fans theorizing how Sherlock survived his suicidal leap in "The Reichenbach Fall" in front of John, even before he came back from the dead. Multiple elaborate guesses are made, and after Sherlock gives his version of what happened, it's left in the air whether or not even that was true. John does say earlier in the episode that the details don't really matter because the reasons behind it all (both before and after) are explained thoroughly.
- Unstoppable Rage: John has a moment of this in the restaurant when he tackles Sherlock to the floor and tries to strangle him.
- Use Your Head: Done to Sherlock by a Tranquil Fury Watson.
- Vitriolic Best Buds: John hits Sherlock in the face multiple times after Sherlock reveals himself to be alive, mainly for keeping it a secret for two years.
- The Watson: Anderson takes on this role during the sequence where Sherlock explains to him how his death was really faked.
- Weather Dissonance: Guy Fawkes Night is celebrated on November 5th each year. However, when Sherlock and Molly are separating, snow is falling outside the building. It does not snow in London, in November, in modern times.
- Whole Plot Reference: To the historical Gunpowder Plot of 1605, similar to fellow fictional work V for Vendetta
- Wild Mass Guessing: In-universe, about how Sherlock managed to fake his death in "The Reichenbach Fall".
- Anderson suggests that Sherlock used a bungee cord to slow his descent, and had Moriarty's body fitted with a mask to look like him.
- A fangirl suggests that Sherlock threw a dummy off the roof to fake their deaths and be with each other.
- Sherlock himself states that he landed on an air cushion, had Mycroft block off the streets except to Sherlock's informants, and left behind the body of the kidnapper who resembled him that he had Molly find from the morgue.
- Word of God here says Sherlock's explanation was the correct one.
- Wire Dilemma: Subverted. Sherlock says he has no idea which wire to cut to defuse the bomb under the Houses of Parliament. He does, however, know that bombs tend to include off switches, which he proceeds to use.Sherlock: There's always an off switch. Terrorists can get into all sorts of problems unless there's an off switch.
- Yaoi Fangirl: A female member of The Empty Hearse imagines a rather... intimate scenario between Sherlock and Moriarty. To elaborate, it involves Sherlock and Moriarty creating a dummy of Sherlock (with the world's most horribly glued on photo for a head), quietly giggling at John's cries of anguish. They pitch the dummy off the roof, and then lean in as if to kiss with swelling romantic music ... cut to Anderson telling her "What?! Are you out of your mind?!"
- You Cannot Kill An Idea: In a reversal of the previous episode, this shows that given enough time, cooler heads were able to re-examine the subject and found major faults in the original theory. Once discredited, the idea quickly dies off and when Sherlock is revealed to be still alive, the public embraces him once again as a hero.