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Baker Street Wiki

The Grand Experiment is the twenty fourth and final episode of season two of Elementary. It first aired on CBS on 15 May, 2014.


Rising tension between Sherlock and Watson bring their partnership to a crossroads, but they endeavour to put their differences aside while they help Sherlock's brother, Mycroft, who faces accusations of treason and murder.


Picking up from "Art in the Blood", Sherlock meets with Mycroft and Watson to inform his brother that he's being framed for murder and treason. Mycroft doesn't believe this and thinks Sherlock is trying to drive a wedge in his and Joan's relationship, but Sherlock proves his point by using the remote starter function on Mycroft's car to activate a hidden bomb inside.

Mycroft is taken to an old, vacant library accessible by Sherlock in order to hide him there. Sherlock figures the mole is too busy with MI-6 work to follow them.

Sherlock meets with Sherrington and his MI-6 associates at their office, and theorizes that Mycroft's "intentions" could be because of a woman - he admits Watson's relationship with his brother has slightly agitated his trust for her. MI-6 refuses to disclose the file they have on Mycroft, but Sherlock nonetheless assures them that they will be informed by him should he personally locate his brother.

Mycroft and Watson converse in the library, and Mycroft laments over how Sherlock would rather be considered wrong rather than go through the trouble of proving himself right, though admitting his lack of ambition - Watson disagrees, pointing out his success as a restaurateur and his work with MI-6, but Mycroft simply criticizes himself, haunted by Sherlock's comments and the fact that their father agreed with him.

That night, Watson meets Sherlock in a car and joins him on his stakeout at Azatan Books, the bookstore under suspicion from Arthur West, the arm-tattooed murder victim from the previous episode. He also notes how MI-6 seems to no longer need his help. Julian Afkhami, the store owner, closes shop and Holmes and Watson break in, with Watson noting the lack of suspicion shortly thereafter. They also discuss Sherlock's disappointment in her desire to move out of the Brownstone.

Sherlock finds a surge protector which he discovers to be a scrambler, into which Afkhami could plug his phones and evade listening devices in his conversations with the mole.

Sherlock deduces that the numbers tattooed on West's arms were metadata from the scrambled calls: date, time and location. Linking the mole to said dates and times will thus locate him. Meeting with Mycroft the following morning with their information, Mycroft sees that he was indeed in all the listed locations at their corresponding times - the mole, therefore, was someone else who was also there with him. Watson realizes Sherrington is the mole, but Sherlock cautions that they must find proof to link Sherrington to the murder before any accusations, and also before Sherrington locates Mycroft.

In the Brownstone, Sherlock gets a call from Sherrington requesting a progress report. Sherlock says that funds from his father are financing Mycroft's escape, but Sherrington asks for additional information upon Sherlock getting it. Watson comes in, but Sherlock declines her help in favor of immediate adaptation to a more independent lifestyle following her moving out. Watson leaves him to it.

Watson wakes up the following morning to a trail of index cards, with dates corresponding to numerous events. Sherlock is downstairs, satisfied with his ability to work on his own. He has also deduced that Sherrington used Mycroft as a cover for various tip-offs to the Iranian government - sixteen of the seventeen calls with Afkhami have been discovered while the seventeenth remains elusive. He gets a call from Captain Gregson.

At the precinct, Gregson and Bell confront Sherlock with evidence that he's aiding his brother, having also learned that Mycroft is supposedly West's killer. Sherlock insists his brother is not a murderer and begs them not to spread the information - Gregson says he hasn't told anyone, but if they want to know that Mycroft is innocent, Sherlock will have to help them prove so. Sherlock warns against it, but an uninformed Gregson feels forced to send out a finest message for Mycroft if Sherlock is unwilling to aid them.

Watson is met by Sherrington at the Brownstone for insights on Mycroft's whereabouts - Watson, unaware that Sherlock had previously come up with another cover story, claims that Mycroft could be in the Catskills, but Sherrington notices the lie immediately and threatens to torture Watson personally if she doesn't cooperate with the truth. Watson activates several TV screens all open with video calls to 15 members of the "Everyone" hacktivists - Sherrington is forced to back out but warns that they haven't seen the last of them.

Sherlock comes home panicking but Watson assures him she's fine. They are both upset that Sherrington is aware of the investigation, but Watson has found the source of the seventeenth call, which has links to the murder of an Iranian man named Nadir Kadem. Sherlock remains distracted by his concern with Sherrington's visit and goes on blaming Mycroft, until Watson stops him by revealing her knowledge of his accidental association with terrorist Sudomo Han, who Mycroft mentioned in the previous episode.

Sherlock sorrowfully visits Mycroft that night and discloses his knowledge of the truth - he believes their helping each other is through a system of them owing each other something, but Mycroft simply says it was out of brotherly love - Sherlock finally understands this, and is both moved and confused. Having reconciled with his brother, he promises to fix their situation.

At the apartment of Iranian murder victim Nadir Kadem, Watson walks in on Sherlock's reconstruction of the blood spatter with red paint. Judging from deductions with the evidence, Sherlock has reason to believe the murder was staged. He begins to acknowledge how beautifully their collaboration works and how their dynamic pattern of breakthroughs keeps their pact steady despite occasional fallout, asking her to stay in favor of this partnership - Watson equally appreciates this but points out how this exciting a way to live, despite its pleasures, has consequences that he can take but she can't. She nonetheless assures him that things will work out, but Sherlock instead concludes in satisfactory happiness, having discovered how Nadir Kadem was murdered.

Mycroft visits Sherrington at a pub and laments him - Sherrington halfheartedly apologizes, also informing Mycroft how he was under instructions from his superior, Sir James Walter, when inviting Sherlock to the case. Mycroft requests the price of undoing the mess, but Sherrington points out how he's unlike wealthy people and their beliefs that money can resolve anything - he was brought up from a rough lifestyle, but MI-6's rejection of "blokes" like him prevented his further promotion and thus motivated him to become a traitor. He observes Mycroft concealing a gun aimed at him and informs him that killing him will mail out a letter to Le Milieu, who's reckless ways can get him killed along with Sherlock and Watson as a result of collateral damage. He instead proposes secretly killing Mycroft himself, calmly assuring him that it's essentially the only option he has at hand.

Julian Akfhami, the bookstore owner and Sherrington's contact, is brought into the NYPD precinct regarding the murder of Nadir Kadem. Sherlock confronts Afkhami with evidence suggesting he stoned Kadem to death, a very hateful and personal way to kill someone - the reason behind this is revealed to be Kadem's affair with Afkhami's wife, which his wife has confirmed plus supplying them with Afkhami's bloodied undershirt he failed to burn along with the other clothes he was wearing at the scene. Afkhami is arrested and confesses to his activities with Sherrington. Bell reports that the morgue picked up the body of a British national.

The victim is Sherrington; Gregson now has reason to suspect Mycroft.

Mycroft is waiting for Sherlock and Watson at the Brownstone and informs them that while he did not murder Sherrington, he rather made a deal with the NSA to have their spies inside Le Milieu kill him instead. He also agreed with the NSA to fake his death through a fire at Diogenes, to protect Mycroft from the rest of Le Milieu. Sherlock points out how Mycroft needs to disappear, perhaps forever. Watson is terribly upset, though Sherlock promises they can fix this - he laments Mycroft nonetheless and his heartbroken brother gives him a hug.

Sherlock later overhears Watson confirming plans to move into a new apartment - disappointed, he goes downstairs and takes the heroin he hid in a book.

Sherlock visits Sir Walter, who offers his condolences for Mycroft. Sherlock inquires whether Sherrington's offer to join MI-6 was real or not. Walter states that Sherrington's intentions were unclear, but the offer itself came from him. Sherlock is satisfied and accepts.



Guest stars[]

Season Two navigation[]

Season Two
#01 Step Nine#09 On the Line#17 Ears to You
#02 Solve for 'X'#10 Tremors#18 The Hound of the Cancer Cells
#03 We Are Everyone#11 Internal Audit#19 The Many Mouths of Aaron Colville
#04 Poison Pen#12 The Diabolical Kind#20 No Lack of Void
#05 Ancient History#13 All in the Family‎#21 The Man With the Twisted Lip
#06 An Unnatural Arrangement#14 Dead Clade Walking#22 Paint It Black
#07 The Marchioness‎‎#15 Corpse de Ballet#23 Art in the Blood
#08 Blood is Thicker#16 The One Percent Solution#24 The Grand Experiment