"I've never made a vow in my life and after tonight, I never will again, so, here in front of you all – my first, and last, vow. Mary and John – whatever it takes, whatever happens, from now on, I swear I will always be there. Always."
Whilst the Watsons are delighted with their newborn, Sherlock believes, after hearing a recorded message from Moriarty, that his supposedly dead adversary has a posthumous plan to attack him. When Lestrade calls him in to solve the mysterious death of cabinet minister David Welsborough's son, Sherlock is intrigued that a bust of ex-premier Margaret Thatcher has been broken and further incidents follow in which busts of Thatcher are destroyed, one involving murder. Sherlock deduces that a priceless jewel was hidden in one of them to smuggle it into England but, when he lays a trap for the thief, he is amazed to learn who is also innocently involved. Somebody whom he must attempt to save from a vengeful associate from a failed operation six years earlier.
Tropes:
- Actor Allusion: the 'Amo' codeword, and specifically Sherlock's conjugating the verb to Mycroft ("Amo - Amas - Amat") is likely a Shout-Out to Benedict Cumberbatch's role in Atonement, in which the character of Lola says the same thing to his character.
- All for Nothing: Ajay's quest for revenge. Not only did he fail to kill his target, it turns out she's not even the one responsible for what happened.
- Arc Words: "AMMO" for this episode, and "[Did you] miss me?" for the overall "Moriarty reappears" arc.
- Attention Deficit... Ooh, Shiny!: Sherlock in the office at the start of the episode. He's telling Mycroft he has reason to be happy because he has returned from a mission that would have spelt certain death for him, then gets distracted by a plate of ginger nuts. One of the officials present asks if he's high, which he is.
- Bait-and-Switch:
- Sherlock states his intention to seek help from a "Toby", and then mentions a genius hacker that he helped out several years ago who thus owes him favours. We then find out that "Toby" is not the hacker himself but, rather, his bloodhound.
- We see John's therapist only to see she's talking to Sherlock instead.
- Beneath Notice: As Mary puts it, receptionists know everything.
- Big Fancy House: The Welsborough house is this, as seen at the beginning.
- Big "NO!": Mary screams two of these when a Moroccan policeman shoots Ajay In the Back, killing him instantly.
- Bilingual Bonus: The two boats in northern Norway are named after Sherlock Holmes stories in Norwegian. They say "Løvens Manke" ("Lion's Mane") and "Flekkete Bånd" ("Speckled Band").
- Blatant Lies: Sherlock tells one client that his wife is a deep cover spy for the last four years as part of a Gambit Roulette by Moriarty to kill the U.S. president and bring down society as we know it. He immediately admits that he's lying.
- Break the Haughty: Sherlock's ego gets taken down a peg every other episode, but he never learns from it. However, Mary's death has finally forced him to realize he is NOT infallible. He asks Mrs Hudson to use the codeword "Norbury" whenever she thinks he's being cocky or presumptive, to remind him of his failure.
- Casting Gag: The grieving father is played by Charles Edward, who played Conan Doyle himself in Murder Rooms.
- Cerebus Syndrome: The show has always been dark, but Mary's death really changes the tone of the show. "It's not a game anymore", indeed.
- Continuity Cameo: DI Dimmock briefly appears as one of the officers Sherlock is helping.
- Continuity Nod: A swimming pool featured during Moriarty's reveal in "The Great Game", and the start of "A Scandal in Belgravia" (it was the one where Carl Powers died). One features in this episode during the fight scene between Sherlock and AJ.
- Curse Cut Short: After Mary arrives to the Moroccan hideout only to find Sherlock already there.Mary: How the fu— [Sherlock cuts her off]
- Dead Man Writing: Mary Morstan pre-recorded a video message that would be delivered to Sherlock and John Watson if she died.
- Dead Guy Junior: Mary names her and John's daughter Rosamund Mary which turns out to be Mary's real name. When Mary dies, her daughter carries her name on.
- Deadly Deferred Conversation: John is about to tell Mary about his cheating (presumably) when Sherlock texts them both, asking them to come to the aquarium, and she asks if he can tell her after. Of course, Mary is killed there, so John never gets the chance to tell her.
- Death Glare: John gives Sherlock an angry one when Mary dies.John: You made a vow!
- Deconstruction: This episode is an example of why one shouldn't always give a villain a "The Reason You Suck" Speech. Sherlock does, despite Mary's warnings not to, and Vivian gets so pissed off that she tries to shoot him. Then Mary jumps in front of the bullet.
- The Dog Was the Mastermind: Turns out the MI-6 leak wasn't Lady Smallwood but her secretary instead.
- Doomed by Canon: Mary didn't survive for long in Conan Doyle's stories so it's no surprise that they would kill her off.
- Eagleland: Mary plays a loud, irritating American tourist while on a plane.
- Early-Bird Cameo: When John bumps into the mystery girl off the bus, the poster in the bus shelter is of Culverton Smith who appears in the next episode as the main antagonist.
- Empty Fridge, Empty Life: A scene towards the end shows Mycroft at home opening his fridge which is completely empty.
- Engineered Public Confession: Vivian is tricked into giving one at the end at the aquarium.
- Every Car Is a Pinto: The car of Welsborough Jr. goes up in an explosion when another car bumps into it.
- Evil Is Petty: Vivian Norberry shoots and kills Mary in response to Sherlock's attempt to Break Them by Talking. It is made clear to the audience that this wouldn't have happened had Sherlock just shut up.
- Foreshadowing:
- Sherlock's voiceover telling part of the story about the merchant who tries to cheat death. Later in the episode, two characters are shot dead: AJ and Mary, although she was Taking the Bullet for Sherlock.
- Mary's comment about receptionists knowing everything.
- Mycroft noting that intelligence agents like Mary don't tend to live long enough to reach old age.
- Also, Sherlock's wedding vow (to always be there for, and protect, the Watson family), and his determination to keep it, being mentioned so many times this episode hints at him ultimately being unable to do so.
- Mary saying "We were like family" and Sherlock replying "Families fall out" serves as this to "The Final Problem".
- For the Evulz: According to Ajay, he was not tortured by the terrorists for information but because they enjoyed it.
- Gender Flip:
- Horace Harker, the journalist from "The Six Napoleons", becomes Miss Orrie Harker. She's also a Killed By The Adaptation Posthumous Character.
- Stanley Hopkins, another Doyle inspector who frequently consulted Holmes, becomes DI Stella Hopkins.
- Greater-Scope Villain: He doesn't have a hand in this episode, but Moriarty (or someone masquerading as Moriarty) apparently has a plan for Sherlock in the works.
- Hastily Hidden MacGuffin: A.G.R.A. is foiled and while on the run, one of the members tries to hide his USB stick with sensitive data. He winds up in a pottery and hides the memory stick in one of six freshly made busts of Margaret Thatcher. Then he gets arrested. Years later, the man goes around stealing all identical busts in hope to find his memory stick. Sherlock puts an end to this.
- Heroic BSoD:
- John has one hard after Mary dies.
- Sherlock seems to as well, especially when he finds out that John pretty much hates him at this point and doesn't want to see him again.
- Heroic Sacrifice: Mary dies saving Sherlock as a way to make up for shooting him in Series 3.
- Immediate Sequel: The first scene takes place minutes after the last episode. The dignity of the scene, set in a government office with top-level officials, is thus heavily undercut by Sherlock still being high as a kite.
- Internal Retcon: MI-6 has arranged it so that Magnussen's death is now attributed to a police officer's "itchy trigger finger", rather than Sherlock, complete with doctored security footage, so no need for a pardon.
- It's Not You, It's My Enemies: When Mary learns that Ajay is after her, she decides to go into hiding in order to keep John and her daughter safe.
- Mexican Standoff: Between Mary and John on one side and Ajay on the other.
- Minor Crime Reveals Major Plot: A broken Thatcher figurine in a completely unrelated case leads to Sherlock discovering an attempt to murder Mary, which in turn reveals a conspiracy within the British Government.
- Mood Whiplash:
- When Mary goes on the run, she leaves a letter for John, and we see John's reaction along with her voice over. It's all very dramatic. That's intercut with Mary pretending to be an irritating American tourist on a plane. It's all very hilarious.
- In the ending, Sherlock and Hudson are sitting around grieving. Sherlock finds someone sent him a DVD labelled "MISS ME" and eagerly pops it into the player. It's Mary's video will, and the first thing out of her mouth is a joke: "I knew that would get your attention."
- Mugged for Disguise: At one point, Mary knocks out a flight attendant and switches clothes with her.
- Multitasked Conversation: John and Lestrade have a pointed conversation in front of Sherlock about dealing with incredibly difficult, annoying, ungrateful loved ones whose messes they have to clean up constantly (on the surface, they're talking about John's new baby, but are also including Sherlock in this group). Sherlock suspects their conversation has a hidden meaning but claims he doesn't get it.
- Mundane Made Awesome: Dramatic, slow-motion dog-walking, with cool music playing. Well, Toby's tracking down a bad guy, but still.
- My Greatest Failure: Sherlock took his vow to save the Watson family very seriously. In a sad ironic twist, he is ultimately unable to keep such a promise, and he takes his failure harder than any case he's had before.
- Mythology Gag:
- It's very blink-and-you'll-miss-it, but the two fishing boats in northern Norway are named after Sherlock Holmes adventures. In Norwegian. Specifically, "Løvens Manke" / "Lion's Mane" and "Flekkete Bånd" / "Speckled Band".
- Sherlock offering to give Lestrade credit for his cases reflects their working relationship from the original novels.
- The case Sherlock is helping DI Hopkins with in the beginning is called "The Canary Trainer", a sequel to Nicholas Meyer's famous Holmes pastiche The Seven Per Cent Solution, based on one of Watson's Noodle Incidents (in "The Adventure of Black Peter").
- Sherlock deduces that a client used to be a manual labourer because one of his hands is bigger than the other. He made the same deduction about his client in "The Red-Headed League".
- Sherlock asks Mrs Hudson to mention the name "Norbury" if she thinks he's getting cocky. Holmes asks the same of Watson at the end of "The Yellow Face".
- John tells Mary that he is not a good man but he thinks he's better than she has given him credit for. A husband said the same thing to his wife in "The Yellow Face" after she expected him to reject her for having a black child from a previous marriage.
- The title of the episode and the expectation of finding a black pearl inside the bust comes from "The Six Napoleons". This is alluded to when the hacker compares Thatcher to Napoleon.
- Sherlock using a dog called Toby for tracking purposes is from "The Sign of Four", and Toby also appeared in other Holmes-inspired stories or adaptations (such as The Great Mouse Detective).
- One of the take-away places on Mycroft's fridge is called "The Reigate Squires".
- Mycroft asks to speak to Sherrinford on the phone. Sherrinford was considered as a first name for Holmes before Doyle settled on Sherlock. In fanon he is the oldest and smartest Holmes brother, the reasoning being that Holmes mentioned that his parents were landed gentry, and since he is doing freelance detective work and his older brother is in the government — something that was common for second sons to do — fanon assumed that Sherrinford is managing the estate. Him being the smartest is an extension of Mycroft being smarter than Sherlock.
- In the montage where Sherlock is solving various minor cases, Watson says that they "can't arrest a jellyfish". A jellyfish was actually the culprit in one of the Sherlock Holmes short stories, "The Adventure of the Lion's Mane".
- When Toby the bloodhound stays still for a looong time during their tracking attempt, Mary states that "He's still not moving," and Sherlock muses that this is "Fascinating". This is straight out of The Adventure of Silver Blaze, where Holmes stated that the "curious incident" of the case was that a certain dog "did nothing in the nighttime" (i.e. did not bark).
- The AGRA acronym is a reference to "the Agra Treasure", which was the McGuffin in The Sign of the Four, Mary's first appearance in canon.
- Nervous Wreck: Mary plays a talkative worrywart on a plane, as part of a Faking the Dead plan.Flight attendant: Everything okay, madam?
Mary: No, no it's not, but what's the use in complaining? I hear a squeaking. Probably the wing will come off, is all. - Nice Job Breaking It, Hero: Sherlock really shouldn't have given that Breaking Speech to Vivian, something that Mary was well-aware of.
- Nothing Is the Same Anymore:
- Mary gives birth to a baby girl, Rosamund Mary Watson, which obviously means Mary and John have less time for mystery solving.
- Mary dies to save Sherlock. John blames Sherlock for it, which damages their friendship severely.
- Not in Front of the Kid: Sherlock causes a Curse Cut Short from Mary by telling her not to swear in front of a child.
- Offing the Annoyance: Once the case is resolved and Sherlock can't stop himself from giving Vivian Norbury "The Reason You Suck" Speech, she decides to pull a gun and try to shoot Sherlock because she has nothing left to lose, considering she's seconds away from being arrested for murder and treason. Mary takes the bullet instead.
- Plot-Mandated Friendship Failure: With Mary dead and a pile of ashes, John Watson is mentioned as wanting nothing to do with Sherlock, blaming him for her death.
- Post-Mortem Comeback: Sherlock assumes Moriarty's "reappearance" is part of a long-term plan, to be put in motion if he didn't survive their confrontation back in Series Two.
- Red Herring: The Borgia Pearl is mentioned constantly throughout this episode as INTERPOL wants Sherlock's help to find it. However it plays no role. Sherlock falls for it himself, and it's what he expects to find in the last bust.
- Remember the New Guy?: We are introduced to DI Stella Hopkins, another officer with whom Sherlock works closely whom we've never met before but everyone else is well-acquainted with.
- The Reveal:
- Sort of. We learn how Sherlock first met Lestrade. An old woman had died in a sauna and everyone was wondering how it happened. Then Sherlock came to Lestrade telling him that she died of hypothermia. Unfortunately, Sherlock cuts in before Greg can tell DI Hopkins the rest of the story.
- "AGRA" is not actually Mary's real initials, but the initials of the first names of the four members of the assassination/black ops group that she was a part of. "AMMO", the mystery person on the phone who sold them out, is not actually Lady Smallwood, but her secretary, Vivian Norbury.
- Rule of Pool: Sherlock and AJ fall into one while fighting each other.
- Running Gag: Everyone trying and failing to get Sherlock to solve the case of the missing Borgia Pearl.Sherlock: It's a pearl! Get another one.
- Screaming Birth: Mary on the way to the hospital.
- Shark Tunnel: The climax takes place in an aquarium, which naturally includes one.
- Short-Distance Phone Call: Welsborough Jr. calls his father pretending to be in Tibet while hiding in the car outside the house for a surprise prank, which goes tragically awry.
- Split-Screen Phone Call: At one point Sherlock and Mycroft hold a phone conversation via split screen.
- Taking the Bullet: Mary for Sherlock.
- Tempting Fate: When Mary goes on the run, she moves at random, at the 'throw of a dice'. Not even Sherlock Holmes could track her. So of course he's waiting in her hotel room. He claims to be able to predict someone's choices using psychology. Then he admits he just hid a tracker in the A.G.R.A. drive.
- Third-Person Flashback: When Sherlock sees the memory stick with the A.G.R.A. label emerging from the sixth Thatcher bust, he flashes back to the scene when Mary handed the stick to John at Baker Street. Included in this flashback is a scene at Sherlock's parents with John saying to Mary "The problems of your future are my privilege," a moment Sherlock hasn't actually witnessed himself.
- Tracking Device: Following John's advice, Sherlock hides one in Mary's memory stick which foils her attempt to go into hiding.
- Travel Montage: Viewers are shown a montage of Mary travelling to different locations using different aliases, intercut with John reading the note she left.
- Trivially Obvious: Mycroft struggles to say something nice when shown a picture of Rosie.Mycroft: Looks very... fully functional.
- Video Wills: Mary leaves one, with the inked label MISS ME?; it's a message to Sherlock to "save John".
- We Used to Be Friends:
- Ajay and Mary, two of the four former members of A.G.R.A., who were all like family to each other. Now, though, Ajay believes Mary betrayed them, has a seething hatred of her and came to England to track her down.
- John and Sherlock's friendship is damaged due to Sherlock failing to save Mary.Molly: I'm sorry, Sherlock. He says — John said if you were to come around asking after him, offering to help, he said he'd rather have anyone but you. Anyone.
- Wham Episode: Mary dies to save Sherlock, which unfortunately wrecks his relationship with John, who blames him for Mary's death.
- What the Hell, Hero?: John gives Mary one for going on the run instead of letting him and Sherlock help her.
