"We've got a serial killer on our hands. Love those, there's always something to look forward to!"Dr John Watson has just returned from service in Afghanistan with bad dreams, a psychosomatic limp and a bullet wound for his trouble. John's therapist encourages him to keep a blog about his life as a returned vet, but it doesn't seem to help since, as John himself puts it, "nothing happens to [him]". And to top it all off, his army pension isn't enough to keep living in London. All in all, things are kinda crappy for John until he runs into Mike Stamford, an old friend from his days at St Bart's. As it happens, Mike knows of someone who's looking for a flatmate...As if to prove this, Sherlock Holmes is introduced to John beating a cadaver with a riding crop For Science!, being completely oblivious to the advances of the St Bart's morgue attendant Molly Hooper and texting people the solutions to murder cases. From a glimpse of John and a brief lend of his mobile phone, Sherlock is able to deduce that John is an army doctor home from service with a psychosomatic limp who disapproves of his alcoholic divorcee brother (though he wasn't quite right).John goes to look at the flat with Sherlock and quite likes it. Sherlock introduces him to the landlady, Mrs Hudson, for whom he did a favour once. After John agrees that the flat would be a good place to live, he is interrupted by the arrival of Inspector Lestrade, who needs Sherlock's assistance with the fourth in a series of identical suicides that have been occurring. Sherlock leaves, before returning to ask John to come along, since he's a qualified doctor who might be able to help. In the taxi, they talk and Sherlock explains his job: he's a consulting detective, one who helps the police with problems when they're out of their depth. He also explains his first deductions of John. John is amazed, naturally, and Sherlock is intrigued by someone who appreciates his deductions.They go look at the corpse, a woman dressed in pink. When they get there, John finds that the police don't like Sherlock — the first officer they meet, Sgt Donovan, calls Sherlock 'freak' and another officer, Anderson, seems to really dislike him (after Sherlock reveals his affair with Donovan, it's easy to see why). Sherlock and John examine the corpse and find a few anomalies: one, she wrote 'rache' on the floor next to her. While Sherlock recognises this as being an incomplete 'Rachel', the question still remains: why? Two, Sherlock sees that she had a suitcase, but no suitcase was found. Finally, her phone is missing. Sherlock has a brainwave and runs out of the scene, leaving John to walk home. On his way out, Donovan gives him some advice: stay away from Sherlock, whom she calls a psychopath who gets off on crimes and puzzles. She also says that she fully expects Sherlock to eventually get bored of solving crimes and start committing them. John gets back to the main road and phones around him start ringing. He finally answers one in a public phone box and is picked up and taken to an empty warehouse, where a man with an umbrella identifies himself as the closest thing Sherlock has to a friend (an enemy) and offers John money to spy on Sherlock. John declines and is taken back to Baker Street.John tells a remarkably unfazed Sherlock about the man's offer. Sherlock isn't bothered by the event and asks John to text a message to a certain number. John sees that Sherlock has the woman's case, and texts the message to the number- the victim's phone. The message is designed to freak out the murderer and gives an address. Sherlock and John go to a restaurant near the address and when a cab arrives, they chase it. However, the cab's passenger has a perfect alibi, and they return home only to find a drug bust in progress- Lestrade, thinking that Sherlock was withholding evidence, orchestrated the bust so he could search the flat. They find nothing, but a cabbie arrives for Sherlock, and he's got the victim's phone. Sherlock follows the cabbie outside, where the cabbie tells him that he doesn't actually kill his victims — he talks to them and they kill themselves. Holmes' curiosity gets the better of him, so he gets into the cab.Sherlock and the cabbie drive to a specially-chosen place, where they play a psychological mind game. The cabbie explains that he has a sponsor, a person who is giving him money for each person he kills, money that will go to his children. In addition, he's dying and thus has nothing to lose. Sherlock milks the killer for information while the killer reels Sherlock in by suggesting his game as the ultimate test of Sherlock's observation and judgement. John follows Sherlock, but the trail ends with two seemingly identical buildings. He picks the wrong building, but at the crucial moment, he shoots the cabbie through a window. Sherlock manages to get the name of his sponsor out of the man — Moriarty.Outside, Sherlock talks to Lestrade about the cabbie until he realises that John killed him. The man with the umbrella and his assistant arrive, and Sherlock reveals who he is — Mycroft, Sherlock's older brother. They have a brief fight before Sherlock and John leave, and Mycroft decides to step up surveillance on his younger brother.
Tropes present in this work include:
- Adaptational Villainy: Jefferson "Jeff" Hope, the cab driver responsible for the murders, uses the same methods as his counterpart in A Study in Scarlet, but most of his sympathetic motivations are removed. In the book, he was an embittered Vigilante Man trying to avenge his wife's death at the hands of fanatical Mormons. In the show, he's a serial killer with a brain aneurysm, who is murdering innocent people for the thrill of outliving others and because Moriarty is giving him enough money to support his children when he's gone.
- Batman Gambit: Jeff Hope pulls one in the final moments of the show. Sherlock already figured out he has no reason to accede his captor's demand to play the deadly game because he has nothing holding him to, the killer's weapon being a prop lighter. As he leaves, Hope asks if Sherlock had figured out which bottle was really poisoned and by that simple question, Sherlock gets baited into playing the game simply by his own desire to prove himself.
- Beneath Suspicion: Cabbies. Everyone trusts them without knowing them. They hunt in crowds because all everyone everyone thinks about is the back of a head.
- Big Brother Is Watching: The most direct example of the series; Mycroft uses CCTV cameras on the street to watch John. Also, he is literally a big brother to Sherlock and tries to bribe John into spying on him.
- Bland-Name Product: MePhone.org.uk
- Blood Knight: Mycroft suggests that John is one, evidenced by how calm and capable he is in dangerous situations, compared to his shakes and his limp in everyday life. As he so astutely notes about the real reason John is seeing a therapist;
- Butt Monkey: Anderson.Sherlock: Anderson, don't talk out loud. You lower the IQ of the entire street.
- Catapult Nightmare: The first scene is Watson waking up from a dream of Afghanistan, but, accurately, not catapulting.
- Character Blog: You can look up Sherlock's website and Watson's blog but Watson's was blank for a while.
- Chekhov's Gun: John has a gun in a drawer shows in the first minute. He takes it later.
- Couldn't Find a Pen: One victim scratches the word 'rache' into the floorboards with her fingernails.
- Double Take: John gets in a blatant one after Sherlock tells him that girlfriends aren't really "his area". Is he gay?
- When Sherlock and John go to the crime scene near the beginning, they hail a cab and hop in without so much as glance at the driver. It turns out, the killer trapped his victims by exploiting similar behavior in them.
- During the opening scene, John's cane is placed across the room from him, where he couldn't readily access it if he needed to. This is an early sign that his leg pain is psychosomatic and that he's prone to forgetting about it.
- Sherlock tells John that the frailty of genius is that it requires an audience. Jeff Hope uses this to bait Sherlock into playing his game, even after he has no reason to.
- Freeze-Frame Bonus: If you pause at just the right time when Sherlock and John catch up with the cab, you can spot Jeff Hope sitting in the driver's seat.
- Getting Crap Past the Radar: Holmes deduces that Donovan spent the night with Anderson. "And I assume she scrubbed your floor, going by the state of her knees."
- Good All Along: Mycroft. In this episode, he gives the impression of being an Affably Evil criminal mastermind with a bone to pick with Holmes. Savvy viewers would be forgiven if they thought he was meant to be Professor Moriarty until the end when it's finally revealed to Watson and the audience that he's Sherlock's brother. When he said he was "concerned" with Sherlock, he was being genuine.
- He Is Not My Boyfriend: When the pair have a stakeout at a restaurant while waiting for the murderer to appear, the waiter refers to John as Sherlock's 'date', which he immediately denies. The waiter pays no attention to this and afterwards brings a candle for the table.
- Hypocritical Humor:
Mycroft: [after showing Watson he can control all the cameras in London and taking him to a secluded location via limo] He [Sherlock] does so love to be dramatic.
- John's first meeting with Mycroft.
John Watson: Well, thank God you're above all that.
- Sherlock considers playing the violin while he's thinking and occasionally bouts of muteness to be his worst habits. He conveniently omits storing bits of dead people in the fridge and firing a handgun into the wall when he's bored.
- Jack Bauer Interrogation Technique: Holmes uses this on the taxi driver to get Moriarty's name. Even if you're dying, you can still feel pain.
- Love Makes You Evil: As Sherlock puts it when working out the motive of a serial killer, "Bitterness is a paralytic. Love is a much more vicious motivator".
- Mistaken for Gay: See above with the Not a Date. It starts a running gag that continues into the second series.
- Mundane Solution: Turns out Lestrade's advice of "don't commit suicide" works pretty well, though it's harder to follow when what appears to be a gun is aimed at your head.
- Mythology Gag: Much of the story takes reference to the original source story A Study in Scarlet.
Sherlock: "No, she was writing an angry note in German. Of course she was writing Rachel!"
- A character who is a Red Herring for being the murderer is an American visiting London for the first time. In A Study in Scarlet, the murderer was an American visiting London for the first time. In both, the killer is a cabbie.
- In the original story the police assumed that the person writing Rache was trying to write the name "Rachel", and Holmes pooh-poohed this by advising them that "Rache" is German for "revenge". Here, the interpretation is reversed in that the victim actually was trying to write Rachel out.
- John finds Sherlock lying down on the sofa moving his arm in a way that made it look (from the audience's POV) as if he had just treated himself to a ringer of cocaine.
- It's a three-patch problem = It's a three-pipe problem.
- The fact that Sherlock is on the nicotine patch instead of smoking his pipe: There's hardly anywhere in London where he can legally smoke in public any more.
- Sherlock's analysis of Watson's phone is almost identical to a passage in the original story where Sherlock shows off his deductive process on Watson's watch. However, one important detail is changed: Sherlock actually gets something wrong. In both versions, he guesses that Harry is Watson's brother. In the book he's correct. In the show, Harry is short for Harriet, who is Watson's sister.
- In "The Problem of Thor Bridge", Watson mentions a case involving a man named James Phillmore who disappeared after going back for his umbrella. One of the victims in "A Study in Pink" is a man named James Phillmore who disappears after going back for his umbrella.
- In the story, Hope is baited up to Holmes' room, where he has the cuffs slapped on him. He tries to escape by jumping out a window, only for Holmes, Watson, Gregson, and Lestrade to catch him. In this, he comes up to the room himself, leading to Holmes figuring it out and going downstairs and having a chat with him. He says he'll surrender, but Holmes will only know why he did it if he plays along. Holmes is later saved by Watson taking a shot that breaks a window.
- Hope killed his first victim in the story using the same method; a choice between two pills, one of which is lethal. The show's Hope offers Sherlock this choice in a school, which is where the story's hope stole the poison from in the first place.
- One of the victims scratches RACHE into the floor with her fingernails. In the original story, this was in blood, written by Hope, and Sherlock notes that the killer has long fingernails.
- Never Suicide: What look like suicides turn out to be the work of a Serial Killer, albeit one that makes his victims kill themselves (by telling them they will be shot, unless they take the 50:50 chance on survival by choosing between a poisoned and harmless pill) rather than killing them himself.
- Nothing Exciting Ever Happens Here: A variant; John says "Nothing ever happens to me" to his psychologist's suggestion that he blogs everything that happens to him. Then a couple of scenes later, he meets Sherlock...
- Not Now, Kiddo: Sherlock to Mrs Hudson, regarding the taxi. He has much bigger problems than a taxi he didn't order, thank you!
- On Second Thought: Sherlock insists that he's not in shock and doesn't need a blanket. Then his chain of deductions lead him straight to John being the one who shot Jeff Hope. He dismisses everything he's said up to this point as the aftereffects of shock.
- Poisoned Chalice Switcheroo: The serial killer has two identical pills, one poisonous and one harmless, and forces his victims at gunpoint to choose one while he takes the other. Sherlock realises the gun is fake and is about to simply walk away, but the killer challenges him into playing anyway. However, before they can actually take the pills, Watson shoots him, and he never finds out which was which (although we can presume that the forensics team will take the two pills and do a forensic analysis to determine this).
- Red Herring:
- The taxi passenger, who has a strong alibi of being new to the country.
- Mycroft, whose introductory scene seems staged to paint him as this series' Moriarty.
- Roof Hopping: Sherlock and Watson do this when pursuing a cab (aided by Sherlock's knowledge of all the traffic stops).
- Say My Name: "Sherlock!"
- Serial Killer: Picking people at random and killing them because "they don't think". He has a sponsor.
- When Sherlock and Watson go to a café to stake out the killer, they walk down Rathbone Street, London W1. Basil Rathbone played Sherlock Holmes in several late 1930s/early 1940s films.
- One address they pair visit is 22 Northumberland Street, which just happens to be right next door to a Real Life cafe called The Sherlock Holmes.
- Take a Third Option: Double Subverted. Rather than play the killer's game, Sherlock decides to take his chances with the gun, which turns out to be a cigarette lighter, correctly deducing that the killer's MO is to outwit his prey, not simply shoot them dead and that the "gun" was merely persuasion. Free to leave of his own accord, Sherlock stands up to do so but then the killer manages to bait him into his game by asking if Sherlock had figured him out, to which Sherlock can't resist and ends up nearly taking the pill.
- Tomboyish Name: During his investigation of Watson's phone, Sherlock notices the name "Harry" on it. Turns out it's Watson's sister, Harriet.
- Trouble Entendre: Played with for laughs; when John is driven to a secret location to meet a sinister gentleman who inquires after his friendship with Holmes and attempts to bribe him for regular updates on Holmes' activities, he becomes convinced by the man's manner that he's some kind of master criminal speaking in these ("I worry about him. Constantly"). Turns out, it's actually Sherlock's brother Mycroft, who was being entirely sincere and (for him) straightforward the whole time.John: So, when you say you're concerned about him, you actually are concerned about him?
Mycroft: [As if John's grown a second head] Yes, of course.
- The Unreveal: Which pill was poisoned?
- Your Princess Is in Another Castle: After realising Sherlock's gone off with the murderer, John tracks them down to a college campus. After frantically searching the building next to where their taxi is parked, he gets to a room with big windows only to see Sherlock and the murderer in the building next door. He makes the most of it by shooting the killer through the window.