Season 2

Complete listed story — includes the ending

1. Step Nine

Gareth Lestrade, a Scotland Yard inspector who worked with Sherlock, is missing. Sherlock and Joan locate Lestrade at a bar in London and agree to help solve the case that caused him to be suspended. Lestrade accused wealthy Lawrence Pendry of killing his wife, but had no proof. Pendry claimed that an armed intruder shot her; the police arrived within minutes and the gun could not be found. A plastic gun turns out to have been made using a 3D printer; Pendry later dissolved it in acetone in a milk bottle after shooting his wife. Pendry's handyman is later found stabbed to death. Pendry printed a second gun to tie up a loose end. The gun exploded when he fired it because he used the wrong ammunition, so he had to stab the handyman with a knife. Pendry's arm injuries from the explosion secure his arrest. Meanwhile, Sherlock discovers that his brother Mycroft moved into his old apartment at 221B Baker Street. Mycroft tells Joan that he wants to make amends with Sherlock after facing a cancer diagnosis and subsequent bone marrow transplant.

2. Solve for X

Mathematician Felix Soto is murdered. His walls are covered in invisible ink with his work, which is about the P versus NP problem, one that has bedeviled mathematicians. Soto's research partner Cyril Nauer is also murdered, and a mugger was shot and left for dead after seeing the killer leave Soto's apartment. The proof that P equals NP would be worth millions. Professor Tanya Barrett evaluated Soto's work and said that they were not near a solution. Sherlock deducts that Barrett solved the problem herself, but needed more time to cash in on it. Barrett is arrested, but the federal government takes over in the interest of national security. Meanwhile, Joan meets with the son of the patient she lost during surgery; she gave up her medical career after that death. The son asks her for money to invest in a bar. She previously bought him a car, and Sherlock thinks that the young man is using Joan's guilt to extract money from her. Sherlock offers her $22,000 to buy him out of her life. She offers it as monetary support only for the son's education, but he reacts coldly to the offer.

3. We Are Everyone

After leaking state secrets to the public, government contractor Ezra Kleinfelter is on the run. A man named Honeycutt hires Sherlock and Joan to locate him. Honeycutt works for Ezra's former employers and would most likely kill him if the detectives found him. Sherlock identifies Ezra's connection with "Everyone," a group of cyber-activists, and deduces the identity of Vanessa Hiskie, an Everyone member harboring Ezra, but she is found dead in her apartment. They also find a box that he took from a bunker where he was hiding and use it to trace him. Sherlock steals a guard's phone, realizing that he is passing messages to Ezra, but Everyone traces it to the detectives and wreaks havoc on their digital lives. Sherlock finds Ezra as he tries to leave the country on a plane owned by an Everyone member. Ezra threatens to expose fourteen American spies unless they let him go. Sherlock contacts Honeycutt and convinces him to release the list of names Ezra has to the authorities so they can get the spies to safe houses. Ezra is extradited and arrested for Hiskie's murder.

4. Poison Pen

Wealthy man Titus Delancy is poisoned. He is found wearing a latex bondage suit; an executive at Titus's company dressed the corpse postmortem to get out of paying a $125 million retirement bonus. Someone named Abigail Spencer works under the name Anne Barker as the nanny for Titus's sons. Years before, Abigail was charged with the murder of her father, who physically abused her. At age 15, Sherlock wrote to Abigail under the name "Sean Holmes". Graham Delancy, Titus's teenage son, ends up being his father's murderer. Graham was sexually assaulted by Titus and killed him to save his younger brother from the same fate. Sherlock reveals to Abigail his identity and says that he knows that she killed her father, citing inconsistencies in their letters and the trial. Abigail confesses to Delancy's murder to protect Graham and to pay for her crime, claiming that the victim used her past to try to extort sexual favors. Sherlock warns that he will be watching to ensure that Graham does not commit any further crimes. Sherlock also offers his ear if Graham needs help coping with what he has been through.

5. Ancient History

At the morgue searching for a case, Sherlock discovers that one of the dead, Leo Banin, is former Russian mafia assassin Vitaly Andropov, who garroted someone the day he died in a motorcycle accident that also claimed a young woman. He was working as a nurse and building a nursing home. Near the scene of the accident lays his victim's body, another hitman who targeted Banin for stealing $30,000 from the mob. Leo was being shot at, and that is what caused the accident. Leo's wife alerted the mobsters to his location. Banin was going to divorce her after discovering her participation in adult films to pay for her passage to the United States, leaving her nothing. He stabbed his first would-be assassin. Banin's wife shot at Banin after the second failed attempt. Meanwhile, Joan's friend asks her to find a one-night stand from a year before. That lover turns out to be Sherlock, who followed Joan at the beginning of their relationship to learn more about her. He reveals his deception to Joan's friend; who responds by sleeping with him again, then tells Joan that she is over him.

6. An Unnatural Arrangement

An intruder invades Captain Gregson's home, terrorizing his wife and asking where he can find her husband. She shoots him, and he flees. Later, two murder victims surface, including Gregson's neighbor Lieutenant James Monroe. The killer went to the wrong house (due to a Google Maps error) and is not actually after Gregson. The victims were assigned to guard an archaeological site. Beth Roney, the archaeologist in charge, stole artifacts from the dig and is now killing her accomplices. Sherlock and Joan remember seeing a valuable bowl, one of a set found at the site, in Roney's home, but when they search her place the next day, it is gone. Sherlock realizes that her ex-husband took it. After being told of evidence incriminating him, the ex-husband confesses and implicates Roney. During the course of the investigation, Gregson is forced to reveal that his wife initiated a trial separation. He becomes angry after learning that she has been seeing another man. However, Gregson does not want to give up, gifting her a dog and apologizing for always putting the job before their marriage. Meanwhile, Sherlock gives Joan access to his box of unsolved cases.

7. The Marchioness

Mycroft is opening a new restaurant named Diogenes in New York City. Sherlock had slept with Mycroft's ex-fiancée, Nigella Mason, to prove to Mycroft that she was after his money. Instead of marrying Mycroft, Nigella landed a marquess. She had an affair with her stablemaster, which led to divorce. She fought hard to get Silver Blaze, a retired champion racehorse, as part of the settlement. The stablemaster is killed by someone trying to poison Silver Blaze. Nigella is charging $100,000 stud fees for Silver Blaze's services. Sherlock proves that the horse died of natural causes, so Nigella substituted his lookalike brother. One of her clients, however, was Joaquin Aguilar, the head of a drug cartel; he found out and sought revenge using a hitman. Sherlock sets a trap for the hitman and catches him. Sherlock and Mycroft promise not to turn her in as long as she pays back her victims, with the exception of Aguilar. Sherlock threatens to reveal that Aguilar sold his foal to another unsuspecting horse lover, unless Aguilar stops seeking revenge. It is eventually revealed that Joan and Mycroft slept together when they were in London and have not since talked about it.

8. Blood is Thicker

A woman named Haley Tyler dies after being stabbed, falling off a balcony and landing on a truck. Haley was the illegitimate daughter of technology mogul Ian Gale, who is dying and needs a transplant. She had the same rare blood type as Gale, and had been donating blood to him. Evidence points to Gale's wife Natalie due to a will amendment giving 20% to Haley, as well as the precise location of the stabbing, suggesting medical knowledge; Mrs. Gale was a doctor. However, Mrs. Gale suggested the will change herself. Haley turns out to have been ill the week before she died. Ian later dies. Mrs. Gale turns out to have murdered both Haley and Ian: she gave Haley medicine that made her body overproduce antibodies; transfusions of her blood killed Ian, and Mrs. Gale murdered Haley to remove a loose end. Mycroft, who plans to return to London soon, proposes that Sherlock come along, saying that Morland desires it. Sherlock refuses the offer, giving a letter to Mycroft to pass on to Morland. Later, Mycroft shreds the letter; he lied to Sherlock and wants him out of New York for other reasons.

9. On the Line

A young woman, Samantha Wabash, commits suicide by shooting herself on a bridge, tying her gun to a weight so it will drop into the river below afterward. She wants to frame a man named Lucas Bundsch as her killer. Samantha believes that Bundsch murdered her sister Allie six years before. Sherlock deduces that her death was a suicide. Bundsch is brought in anyway, but passes a polygraph test. However, Sherlock deduces that Bundsch fooled the test and concludes Bundsch was responsible for Allie's murder, as well as others. Bundsch abuses his victims for weeks before killing them. Bundsch goads Sherlock, humiliating him and Joan at one point with a wild goose chase. He texts Sherlock, using an untraceable burner phone, the address of the woman he has just taken. Sherlock finds from blueprints that when Bundsch's recording studio was built, the building lost square footage. The police find a hidden door. Sherlock picks the lock and frees the latest abductee and a woman Bundsch had held captive for years.

10. Tremors

Silas Cole, a schizophrenic young man, dressed as a knight, wanders into the police station with a gun and states that he had to kill the queen. Silas's ex-girlfriend is dead, shot through the heart. However, Sherlock is convinced that Cole did not kill her; his "knight's code" would have prohibited destroying her heart, thought in medieval times to house the soul. In the course of their investigation, Sherlock unintentionally gets a man fired by revealing he is out on parole. Bell is shot in the stomach, jumping in front of Sherlock when the man comes gunning for him. The victim's heart later turns out to have been enlarged; she was participating in a trial drug program, and her doctor killed her to cover up the drug's failure. Bell asks Sherlock not to come see him anymore during his first hospital visit.

11. Internal Audit

After his Ponzi scheme is uncovered, hedge fund manager Donald Hauser is tortured for information before being killed. The woman who finds the body is a former sober client of Joan's. She refuses to allow Joan to reveal their relationship, hindering the investigation when her former drug dealer becomes the main suspect. The reporter who broke the news of Hauser's fraud is murdered the same way hours later and her laptop is stolen. Hauser turned over evidence to her that contained information about another crime. Later, the dealer's body is found in a dumpster behind an art gallery in which he is a silent partner. It turns out that Jacob Weiss, a client of Hauser's who runs a nonprofit recovering money for the heirs of Holocaust victims, was embezzling the funds. He used the gallery to launder the money. Hauser knew about it, but made the mistake of informing Weiss that he was going to reveal everything. Meanwhile, Sherlock becomes the sponsor of someone named Randy. Bell is offered a position with the Demographics Unit; if the nerve damage to his arm cannot be fixed, he will have to take a desk job.

12. The Diabolical Kind

Sherlock recognizes the voice of the man who pretended to be Moriarty in the past when the man calls with a ransom demand for a kidnapped child. Moriarty is brought in, though in electroshock hand restraints, to help track down the kidnappers in exchange for favors. The child turns out to be her daughter. Moriarty's lieutenant wants a collection of valuable information Moriarty has amassed over her career. After disabling her restraints, escaping and dealing with all her daughter's abductors, an injured Moriarty allows Sherlock to take her back into custody, predicting that she will be free soon anyway. Sherlock realizes that she may have started to redeem herself; she refrained from killing her head jailer when she escaped.

13. All in the Family

An assignment with the Demographics Unit leads Bell to discover a body in a barrel. The victim is a member of the Pardillo Mafia family who had been in hiding for years. A member of a rival family becomes a suspect. He dies from a car explosion some time later. The National Security Agency (NSA) supplied the killer with information about Pardillo's whereabouts. Sherlock confronts an NSA agent, accusing the agency of having a leak. The agent says that Bell's new boss, NYPD Deputy Commissioner Da Silva, requested the information. Da Silva was trying to dispose of everyone who knew about him working for the Mafia for his entire police career. Sherlock informs Bell, who steals evidence linking Da Silva to the Pardillo family. They set a trap; when he tries to assassinate Robert Pardillo, the victim's father and head of the family, the police are waiting. Bell rejoins Major Crimes.

14. Dead Clade Walking

While investigating one of Sherlock's cold cases, Joan spots an out-of-place rock in the murder victim's garden. She enlists a geologist to study the photo. Joan eventually steals the rock. It contains a very rare complete dinosaur fossil worth millions. The rock is later stolen from the police evidence room. Tracking down a very high-end smuggler, Sherlock and Joan find the man murdered and the fossil smashed to pieces. They eventually determine the curator of a natural history museum committed the murders to destroy proof of a scientific theory that would have ruined his reputation. Meanwhile, Sherlock has his hands full as a sponsor when Randy's addict girlfriend turns back up in his life.

15. Corpse de Ballet

When a ballerina is murdered, evidence seems to point to the dance company's star performer, world famous diva Iris Lanzer. The killer steals a hard drive containing the venue's surveillance footage. Sherlock is convinced Lanzer is not guilty; he accepts her offer to sleep with her. An audio recording is leaked to the tabloids, it reveals Iris's intimate relationship with the victim, but Sherlock deconstructs the recording and deduces that Iris's lawyer is the murderer, using the publicity to further his career. The police find the stolen hard drive in the lawyer's home. Meanwhile, Joan looks into a missing homeless man, a veteran with severe post-traumatic stress disorder, prompting her to open up to Sherlock about her biological father, who is schizophrenic and lives on the streets. Joan locates the missing man, kidnapped and held captive with two others by a couple who collect their benefit checks.

16. The One Percent Solution

Sherlock and Joan are called to investigate a bombing at a restaurant that targeted finance executives and government officials. On the case, they are reunited and forced to work with Gareth Lestrade, who is now consulting for one of the CEOs involved in the case. Videotape from the hotel attached to the restaurant leads Sherlock and Joan to suspect that Lestrade is covering up his boss's involvement. The CEO is being targeted by a blackmailer who knows about the women (and occasionally men) who have traded sex for favors and that Lestrade has been the intermediary making the actual offers. The CEO is forced to reveal his involvement in order to catch the blackmailing bomber. A subordinate of a government bureaucrat killed her boss so she could take his position and see the federal jobs report before the general public, information she could use to make a fortune in the stock market. Lestrade loses his job and comes to stay with Sherlock and Joan.

17. Ears to You

Gordon Cushing's wife disappeared in 2010; he was acquitted in a murder trial, but many people still think he is guilty. One day, he receives two severed human ears along with a ransom note. The DNA matches that of Cushing's wife, Sarah. At the ransom exchange, Cushing pursues the suspect and unintentionally kills him. Clues on the suspect's body lead Sherlock and Joan to an AA meeting, where they find Sarah, who is both alive and not earless. Sarah says that the DNA they collected when she disappeared was not hers and belongs to her husband's mistress; however, she died in 2011 in a car accident. Sherlock realizes that Sarah's plastic surgeon husband grew two exact replicas of her ears on her back and then cut them off in an elaborate attempt to collect the ransom from Cushing. Meanwhile, Lestrade is mugged and Joan encourages him to solve his own case in order to lift his spirits and get him to move on with his life. He is successful and accepts a position with the Garda Síochána, the Irish national police.

18. The Hound of the Cancer Cells

Researcher Barry Granger has been testing the "Hound", a breathalyzer for detecting cancer. He is eventually murdered. His research was alleged as fraud by an expert in the field under the pseudonym Adam Peer. The allegation looks set to ruin both Granger and the firm that employed him, a company run by Hank Prince. The allegation is actually false, and Peer was two people: Granger and another, but Prince hacked their email to make the fraud allegations against Granger. Prince later murders his wife. Earlier he had tried to trash his firm's value by masquerading as Peer and impugning Granger, so that she would receive in their divorce only some of the company's depressed value, which would then rebound once Granger's research was vindicated. Bell, recovered from his injury and returned to field duty, asks Joan to find a missing witness to a street killing. She changed her mind about testifying after she became pregnant and is hiding with a former tutor, Manny Rose. Bell tells Rose to tell the witness that her testifying does not matter as they will get the perpetrator next time. The killer and Rose are later found shot to death - Rose decided to dispense his own vigilante justice.

19. The Many Mouths of Aaron Colville

Bite marks on two murdered women echo the trademark of Aaron Colville, a man convicted as a serial killer who subsequently died in prison. This raises the question of Colville's possible innocence. The bite marks are traced to ex-con Alan Vikner with the help of hacker collective Everyone. However, when he is brought in, Vikner shows that he has dentures; eight sets were made from the same mold (of Colville's teeth) for inmates at Colville's prison. Eventually, Sherlock and Joan eliminate all the convicts as suspects. Finally, Sherlock realizes that the person who stands to benefit the most from exonerating Colville is his mother, who has sued the city for millions of dollars in his alleged wrongful conviction. Joan has a connection with the murders, as she was a part of the operating team that tried to save Colville's life. She suspects that the doctor in charge recognized Colville and may have deliberately erred in the resuscitation procedure. She has no proof, and the doctor tells her that he himself is not sure if he did or not.

20. No Lack of Void

When a pickpocket collapses in jail, Joan starts to help, then realizes he seems to have contracted anthrax. He stole the anthrax from someone, thinking it was cocaine, then swallowed it when he was apprehended. The man dies. One of the pickpocketed items leads to Charlie Simon. He had the expertise to make anthrax spores, but they find him dead at his storage locker laboratory. From the empty trays there, Sherlock deduces he made 40 pounds of the stuff. Eugene MacIntosh, a member of an anti-government group known as the Sovereign Army, becomes the prime suspect. He is shot dead by his brother Bart when he goes to Bart's failing farm. However, it turns out that the brothers were actually trying to kill off Bart's herd of cows for a multimillion-dollar insurance scam. Sherlock's close friend Alistair dies, which catches Sherlock off guard. He reacts by acting out of character, causing Joan to go into sober companion mode and making him talk about it. After it gets out that Alistair died of a heroin overdose, Sherlock struggles even more. Eventually, he confesses to Alistair at his grave that he loved him dearly and will miss him.

21. The Man with the Twisted Lip

Sherlock and Joan investigate the disappearance of Paige, the sister of a woman who frequents Sherlock's sobriety meetings. At the brownstone, they are surprised by Mycroft, who returned to New York, apparently to focus on Diogenes. Later, Joan meets Sherlock at a park he found based on a clue in one of Paige's songs. The pair find two bodies there, Paige's and that of a Zach Piller, who manufactured drones for a company called McCarthy-Strauss. The two victims were killed by Piller's drones. Sherlock later visits Diogenes and sees Guillaume de Soto, a high-ranking member of French drug cartel Le Milieu. Sherlock then captures a drone that was spying on him. Piller's psychiatrist says that he accidentally misidentified ten undercover CIA agents in Afghanistan, who were then killed by friendly fire. He subsequently wrote a report on it out of guilt. The psychiatrist is eventually poisoned by another drone. To incriminate McCarthy-Strauss, Sherlock waits at a pier to meet with the business executive that Piller's report belongs to, while Joan breaks into the executive's office and steals the report. That night, Joan follows de Soto's contact Marchef outside Diogenes after he receives an envelope. She retrieves the envelope, but finds a picture of herself inside. The contact kidnaps her.

22. Paint It Black

Mycroft receives a call from Joan's kidnapper. Le Milieu previously offered Mycroft money to open up Diogenes in New York to serve as their headquarters, followed by various requests. Meanwhile, Swiss bank executive Pierce Norman plans to sell a list of thousands of bank executives' names and information to the black market. The NSA is onto Norman, but Sherlock wants to get to him first. Norman's boyfriend points the brothers to a remote home his lover owned. There, they find Norman's corpse. Norman was killed before the list was downloaded and was framed. Joan, meanwhile, operates on a Le Milleu soldier who was shot in the abdomen. She insists that the man be taken to a hospital or he will die; her kidnapped shoots him. That night, Sherlock and Mycroft track down the real perpetrator, Norman's employer's head of security, Kurt Yoder. Yoder is interrogated that night at the brownstone and eventually mentions the hard drive the list is on. After recovering it, Sherlock decides to call the NSA, fearing that Le Milieu will betray them, but Mycroft, who is under orders from a British contact, incapacitates Sherlock with a taser and heads out to meet the dealers, while the NSA later refuses Sherlock's requests to save Joan. Mycroft gives Yoder and the list to the dealers, but de Soto orders his henchmen to kill them, and leaves. Mycroft signals British Intelligence snipers, who kill de Soto's men.

23. Art in the Blood

Sherlock returns home to find Joan safe. Mycroft is actually working for MI6. MI6 utilized Mycroft's observational skills to investigate criminal groups such as Le Milieu. Mycroft's handler, Tim Sherrington, wanted Sherlock out of New York. Sherrington hires Sherlock to investigate the murder of Arthur West, an MI6 analyst. West's arms were stolen from the morgue. West's estranged wife, Marion is a tattoo artist; she tattooed West's arms with information using invisible ink. West was confident that there was a mole within MI6, communicating with bookstore owner Julian Afkhami. Sherrington eventually offers Sherlock a job at MI6. Marion, meanwhile, tells Joan about one "Sudomo Han". Mycroft had left MI6, but rejoined in exchange for Sherlock's freedom. While he was a drug addict in Britain, Sherlock had worked for Han as a courier, unaware that the latter was a terrorist. Joan and Mycroft eventually have sex. Elsewhere, Sherlock learns that the gun used to kill West bore fingerprints bearing a distinctive scar. He identifies the fingerprints as Mycroft's.

24. The Grand Experiment

Mycroft is being framed as the mole, so Sherlock relocates him and Joan to a vacant, remote library accessible only to Sherlock. The three identity Sherrington as the mole, but decide to keep it quiet. Sherrington eventually visits Joan at the brownstone to confront her, but Joan had invited members of "Everyone" to a video chat to have witnesses for protection. Sherrington leaves. He had made seventeen calls to his contact Afkhami, who is spying for the Iranian government. Sherlock and Joan investigate a murder believed to be linked to Afkhami. He deduces that the victim was stoned to death. Afkhami's wife was having an affair, so he killed her lover. Sherrington betrayed MI6 because of a lack of promotion or respect due, he believes, to his working-class background. The NYPD later finds Sherrington's corpse. Mycroft made a deal with the NSA for them to kill Sherrington and fake Mycroft's own death to protect Joan and the brothers from Le Milieu. Mycroft embraces Sherlock and says that he loves him. While Joan makes plans to move into a new apartment, Sherlock accepts MI6's invitation to join them.