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Baker Street Wiki

Watson: "Ah. So that means you might still be the smartest person in the world."
Holmes: "I would never suggest that."
Watson: "Really? I think that's the first time I've ever heard you say anything remotely modest."
Holmes: "It's not modesty. There's just no reliable way to test the hypothesis."
Joan Watson and Sherlock Holmes

"The Leviathan" is the tenth episode of season one of Elementary. It first aired on CBS on 13 December, 2012.


When a supposedly impregnable bank vault called 'The Leviathan' is breached for the second time, Sherlock is called in to figure out what went wrong. When the vault was breached for the first time, the heist was committed by a once-in-a-lifetime assembly of world class criminals. Because they went to jail for the crime, the vault company cannot imagine how anyone else got in. When Sherlock learns that not even he can break into The Leviathan, he realises that the second group of criminals must somehow be connected to the first.


Part One[]

Joan Watson comes down for her morning jog as someone is ringing the doorbell. She is discombobulated to meet not one, but two half-dressed call girls (identical twins Gwen and Olivia Lynch) in the living room, enjoying coffee and crepes. As they head upstairs to get dressed, Sherlock emerges from his bedroom, still sleepy, and starts to explain the "mutually beneficial" relationship he has with the sisters - he gets to study the major differences that arise between two otherwise genetically identical people, and in exchange they get- "I didn't ask!" Watson states firmly.

She answers the door to Micah Erlich, president and chief engineer of Casterly Rock Security. In 2009, his company marketed a supposedly "impregnable" bank vault, the "Leviathan," and, in Holmes' words, "paid the price for your hubris" when four thieves managed to crack one less than a year later. Erlich says the thieves were brilliant, and, though his company tried to improve on the Leviathan since then, they didn't try very hard, figuring that the chances of a collection of such genius criminals coming together again were virtually impossible. Yet the evening before, four thieves cracked the Leviathan guarding the contents of the Svalbard Diamond Exchange. Erlich says his company needs to know how the Diamond Exchange's safe was cracked, immediately, or banks all over the country will start demanding their money back - at over a million dollars per safe, that will ruin the company.

Erlich believes that there must have been a fifth conspirator, who was never caught. Holmes scoffs, saying that if one group of thieves could figure out how to defeat the Leviathan, then so could another. To prove it, he has Erlich escort him to the Diamond Exchange, predicting that it will only take him an hour or two to figure out how the thieves broke in.

Once confronted with the safe, however, Holmes is stymied: while any semi-competent gang of thieves could defeat the rudimentary security features leading to the vault, and a clever one could even photograph and duplicate the key used to open it, the door is protected by a ten-digit access code, created by a random number generator that changes the code every two minutes. The only person who has the code is the Exchange's owner, who has it on a key fob. Since the owner is abroad in Switzerland, and has never let the fob out of his sight, the thieves didn't get it from him. Holmes admits he will need a little time with this one...

Seventeen hours later, Holmes is still seated on the floor, staring at the vault room door. Watson, who arrived hours ago, has fallen asleep. Holmes rousts her awake and assures her that he will figure it out, given a little more time. She reminds him that it is 2:00am, and she needs to get home to get ready for brunch with her mother. Sherlock agrees, asking her to wait while he tries just one more idea: smashing open an emergency box and hacking at the instrument panel with a fire axe. Naturally, this fails to open the vault.

Part Two[]

That morning, Sherlock has the details of the earlier heist laid out before the fireplace. To Sherlock, the solution is simple: one of the original four thieves (of which three are still living) must have sold their secret to a third party. Watson points out that this hypothesis rests on the assumption that, since Sherlock couldn't figure out how to open the vault, then no one other than the original four thieves else could have either.

Joan meets her mother for brunch, who invites her to dinner with Joan's brother, Oren and his girlfriend, but Joan says she can't while she is on a companion job. Her mother begins to express her disapproval of Joan's new occupation, but they are interrupted by an insistent phone call from Sherlock, who says one of the original four thieves, Charles Briggs, has agreed to meet with them.

Briggs is a master locksmith, but claims he doesn't know how they defeated the code key to the Leviathan. The mastermind, Carter Averill, did that, and never told the others. However, before he died, Carter told Briggs that someone had contacted him in prison, offering him money for the secret. Briggs doesn't know the man's name, only an alias: Le Chevalier.

Outside the prison, Watson scoffs, saying that Le Chevalier might as well be a legend, for all that is known about him, and Briggs is sending them on a "snipe hunt." Holmes is undaunted, reminding her that if Le Chevalier has never been caught, it can only be because Holmes, has never gone looking for him.

Sure enough, while examining photos of the museum opening when Van Gogh's Pieta was unveiled, and stolen, on the same night, Holmes notices the museum's benefactor, Peter Kent, wearing cufflinks made from ancient Greek coins, the theft of which was also attributed to Le Chevalier.

Sherlock and Watson visit Kent's home, where Sherlock notices a lithograph of Pieta on the wall, alongside several genuine, priceless works of art. Suspecting something, Holmes smashes the glass (to Watson's horror) and cuts through the paper with his butterfly knife, peeling it back to reveal the genuine painting underneath. Peter Kent is Le Chevalier. Peter's son, Alan, runs in, demanding to know what Holmes is doing. Confronted with the stolen artwork, he says he doesn't know anything about his father's past activities, but is positive that he didn't rob the Diamond Exchange two nights earlier. For proof, Alan shows them his father, who had a stroke two years ago and has not spoken or stood on his feet in eighteen months. Peter Kent may be Le Chevalier, but he did not breach the Leviathan.

Part Three[]

Holmes and Watson walk to the police station, carrying a box of Peter Kent's stolen artifacts. Watson is still reeling over the fact that she rode the New York subway with a diamond-encrusted watch worth about $25 million in her pocket, while Holmes is carrying the Pieta (worth about $50 million) in a tube under his arm. Holmes says it was the simplest solution for all concerned: they return the stolen items to their rightful owners without naming names, since Holmes has little interest in putting a stroke victim in jail, and Alan Kent doesn't want the world knowing his father was a master thief. Watson says she looks forward to seeing Holmes offering that as an explanation for their "grand larceny" in court.

Holmes stops dead, realizing Watson has hit on a vital clue: Carter Averill, the mastermind of the original heist, was tried in court, which means all the details of the crime are public record, and someone may well have figured out the solution to the Leviathan from that. Again, Watson points out that Holmes is only insisting on his "copycat" theory because he can't accept that someone else might have figured out, on their own, how to defeat the Leviathan.

At the police station, Holmes and Watson return the priceless artifacts to Captain Gregson, who is smart enough to link them with the search for Le Chevalier, but is willing to ask no questions. As Holmes gets up to leave, Gregson points out the tube under Holmes's arm, and Holmes says it is just something he picked up for his apartment.

Back home, Watson is appalled to see Holmes hanging Pieta over the fireplace. He says he is only "delaying its return," and while she is insisting that he return the painting to the museum in the morning, her phone rings. On the other end, her brother, Oren, says he got her text, accepting their mother's invitation to dinner, and he is so excited to see her and meet her latest client. Watson, cornered, accepts, then hangs up and fumes at Holmes that her phone was locked. Holmes says he may not have been able to defeat the Leviathan yet, but her phone was child's play. She refuses to let Holmes near her family, but he says he feels a "relapse" coming on, and she fumes, knowing that he knows she can't leave him alone when he says that word.

At the crack of dawn the next morning, Holmes rousts Watson out of bed, saying she has thirty minutes to breakfast and get dressed, to let them get to the city clerk's office just as it opens: according to the trial transcript, the jury requested to examine one exhibit three times: a slip of paper with the thieves' names on it, which was used as a coffee order. Beyond proving that the four thieves were working together, a slip of paper with their names on it is hardly a "trove of information."

Examining the paper at the clerk's office, Holmes excitedly recognizes a seemingly random sequence of numbers and letters on the reverse side as a snippet of Malboge, an obscure programming language. Then he looks at the profiles of the jurors, and identifies one, Justin Guthrie, as a former software engineer.

While on their way to Guthrie's apartment, Holmes receives a text from a consultant friend in London, who has translated the Malboge snippet from the receipt: the formula for pi. Holmes explains: the thieves hacked into the Leviathan's number generator and used the Malboge to reprogram it to spit out multiples of the number pi. Since pi is infinite, the numbers generated would still appear random at any given time, when in fact the thieves who knew the algorithm could predict the access code. As incredible as it seems to Watson, Holmes' theory appears correct: some member of the jury who tried the original thieves planned the diamond heist.

When the arrive at Guthrie's apartment building, they find a uniformed policemen outside, who informs them that Guthrie is dead, having jumped from his apartment window that morning.

Part Four[]

When Captain Gregson and Detective Bell arrive, Holmes points out two vital clues: a spot of blood on the floor, likely thrown out by someone being punched in the face, meaning it likely belongs to Guthrie's killer. Then he points to three glass vases, filled with multicolored decorative rocks, one of which is only partly full. He empties it out and picks out a plain white one that, on closer inspection, is an uncut diamond. Guthrie robbed the Diamond Exchange with four others, at least one of whom killed him and relieved him of his share of the stones.

Watson reminds Holmes that they should start getting ready for dinner with her family, but he begs off, reminding her that their case is now a murder investigation. Trying not to appear too relieved, she agrees to go by herself.

However, that evening, she arrives at the restaurant to see Sherlock regaling her mother, brother and his girlfriend with tales of their exploits. As she sits down, her family reveals that Sherlock has been talking her up generously, crediting her with both his recovery and his success in many of their past cases. Sherlock says Joan is responsible for rebuilding his life "from the ground up," which has led to many crimes being solved. Joan's mother appears impressed for once, admitting that she never thought about Joan's occupation that way.

As they are riding a cab home, Watson thanks Holmes for managing to reach her family when she has never been able to. Holmes shrugs and said he meant very little of what he said; her family are irredeemably conventional people, and can't understand his (or her) affinity for the bizarre and the unconventional, so Holmes just mouthed some polite nothings to satisfy them. She notices him browsing through the contents of Justin Guthrie's cell phone, and he notes that he listed three people, by their first names only, under his "notes" section instead of in his contact list. Holmes notes that all three names belong to fellow members of the jury Guthrie served on.

At 3:00 a.m. that morning, Holmes is lying on the couch, "basking" in the sounds of Beethoven's Ode to Joy, turned up full blast. Watson staggers in from her bedroom and shuts off the stereo. An elated Holmes reveals that he has solved the case.

The original four thieves were a locksmith, an inside man, an all-around genius who cracked the Leviathan's code, and an electrical engineer. Then Holmes turns to the jury that tried the thieves: Guthrie, a software engineer; Alex Wilson, an electrical engineer; Jeremy Lopez, a locksmith; and Amelie Widomski, nee Batonvert, the sister of David Batonvert, the floor manager of the Diamond Exchange. Holmes has identified the four thieves who robbed the Diamond Exchange, theorizing that, during the course of the trial, the four of them must have noticed, with amusement, that they "possessed the same skill set" as the original thieves, but once Guthrie realized the secret of the computer code, "things turned serious," and they began planning a heist in earnest. The only mystery, Holmes says, is which of the three remaining thieves - Wilson, Lopez, or Widomski - killed Guthrie.

The surviving jurors are summoned to the police station, except for Wilson, who cannot be found. Right away, Holmes notices that Jeremy Lopez has a bruised face, and, unlike Widomski, is hefty enough to have heaved Guthrie out the window.

Captain Gregson informs the jurors that one of their number has been murdered, and he is requesting a DNA swab from each of them. Holmes is surprised when Lopez does not protest, and swabs the inside of his cheek along with everyone else. This seems to rule him out as the killer. Then Bell comes in, saying a policeman in New Jersey has identified Alex Wilson's address.

While Bell knocks on the door of Wilson's apartment, Holmes and Watson are swatting at flies buzzing around the doorstep. There is no answer, and Holmes grimly notes that the flies are coffin flies, drawn to rotting corpses. Wilson's dead body is found underneath a refuse heap, suffocated by a plastic bag over his head. Given the advanced decay of the body, Wilson has been dead for at least two days, and could not have killed Guthrie.

Part Five[]

Returning to the police sation, Holmes, Watson and Bell are informed that they have a DNA match for the blood from Guthrie's apartment: an Army Chaplain named Audrey Higuera. Holmes, baffled, asks what her connection with the jury was, and Gregson reports that, as far as they can tell, she has none.

As the police enter Higuera's home with a search warrant, Holmes refuses to believe the evidence; Aguirre simply "doesn't fit." Watson reminds him of his own maxim, "when you've eliminated the impossible..." Aguirre's home is empty, and photos show her to be a devoted Chaplain, currently posted overseas in Afghanistan, and an enthusiastic volunteer at the local hospital. Again, Holmes says she doesn't fit, but then Watson notices a "thank you" badge on Aguirre's table that she recognizes from her days at the hospital - given to bone marrow donors.

Jeremy Lopez is called back to the police station, and politely asks what more he can do, since he already gave up his DNA. Holmes points out that, according to his medical records, Lopez recovered from cancer two years earlier, thanks to a bone marrow transplant from Aguirre. These transplants can cause some confusion with DNA testing, but a blood test will be 100% accurate. Lopez refuses to submit to a blood test, but Gregson informs him they already have a court order requiring him to submit to one. Lopez is cornered, knowing the police have him cold on two counts of first-degree murder. Gregson suggests that, if Lopez gives them enough evidence to arrest and indict Amelie Widomski, Lopez may have a chance of being released from prison before he dies of old age.

That evening, Holmes carries in a case of champagne bottles, a grateful gift from Casterly Rock Security. He grumbles that they should have checked to see whether he drank champagne before spending $500 a bottle, and invites Watson to either have a glass herself, or pour it into the sink. As she is doing the latter, the doorbell rings, and Holmes answers it to Mary Watson.

In private with Joan, Mary says that she has never made a secret of her disapproval of Joan's new career - nor is she so gullible as to take all of Sherlock's generous praise at face value - but over dinner, she noticed a spark in Joan that she hasn't seen since her old days as a surgeon. Against all her expectations, Mary believes that whatever working relationship Joan has with Sherlock is special. Joan demurs, saying Sherlock is just another client, and soon she will move on to her next one. Mary asks Joan if her next client will make her happy. "People find their paths in the strangest of ways."

Before Joan can reply, Sherlock walks into the living room and turns on the TV, saying he knows they will want to see what's on. The news reports the "anonymous" return of Van Gogh's masterpiece Pieta to the Aster Museum, it's rightful owner. Joan cannot help but smile.

Behind the scenes[]


  • Casterly Rock Security, the name of the Leviathan's manufacturer, is a reference to Game of Thrones.
  • The master thief's alias, Le Chevalier, is French for "The Knight."
  • Over dinner, Oren Watson refers to the events of "The Rat Race."
  • Gwen and Olivia Lynch, the twin sisters, are actually played by a single actress, Tonya Glanz.

Continuity error[]

  • When Sherlock is first playing the piano in Guthrie's apartment, his hands are bare; but when he stands up after finishing, he is wearing gloves.




  • Freda Foh ShenMary Watson
  • Stephen ParkOren Watson
  • Gbenga AkinnagbeJeremy Lopez
  • Reg RogersMicah Erlich
  • John Bolger - David Batonvert
  • Jennifer Kim - Gabrielle Harper
  • Tonya Glanz - Olivia Lynch/Gwen Lynch
  • Glenn Kalison - Alan Kent
  • Dee HotyPatsy
  • Sean Dugan - Charles Briggs
  • Nathaniel McIntyreUniform
  • Sue SimmonsReporter

Season One navigation[]

Season One
#01 Pilot#09 You Do It To Yourself#17 Possibility Two
#02 While You Were Sleeping#10 The Leviathan#18 Déjà Vu All Over Again
#03 Child Predator#11 Dirty Laundry#19 Snow Angels
#04 The Rat Race#12 M.#20 Dead Man's Switch
#05 Lesser Evils#13 The Red Team#21 A Landmark Story
#06 Flight Risk#14 The Deductionist#22 Risk Management
#07 One Way to Get Off#15 A Giant Gun, Filled with Drugs#23 The Woman
#08 The Long Fuse#16 Details#24 Heroine