Plot

Sherlock helps a math genius from his network of "Irregulars" experts after he stumbles upon a body while participating in a math puzzle competition. Meanwhile, Joan attempts to extend an olive branch after she learns about Kitty's past.

"Elementary" - "Just a Regular Irregular" - Nov. 13,2014

We open on Kitty working the stick ona dummy when Joan enters. Kitty tells her he's arguing with one of his experts, someone named Phillip, who is a knife-thrower.

Phillip turns out to be NFL superstar Phil Simms who wants to keep his connection to Sherlock under wraps. Turns out he's the greatest knife-thrower of his generation but he could make more money playing football. He demonstrates his skills on the dummy and leaves. Joan is impressed and confused. Sherlock is sad he wasted his talents for competitive blade-slinging.

Watson asks Kitty to help her with a stakeout and says she'll cut her in on her fee. She's been asked to follow a man and he thinks he's noticed her. Kitty says she works for Sherlock not Joan. She passes.

We cut to Harlan Emple, another of Sherlock's experts that we met last season-- and played by Rich Sommer, Harry on "Mad Men"-- working out a complex math problem on a blackboard, as always, shirtless. He figures out whatever he wanted to figure out and we watch him enter an abandoned warehouse looking for something. He opens a locker and a dead man, encased in mothballs, falls out onto the floor. This does not appear to be the thing he was looking for.

At the precinct house he is, impatiently, trying to explain to Bell and Gregson that he is not a murderer. He explains that, apparently, legions of math geeks often partake in what is known as "puzzle hunts." They are sent elaborate math problems that, once figured out, provide GPS coordinates. They go to these coordinates where they receive another clue/problem and continue on.

Although they are often for fun, they are also sometimes for cash and prizes, this one had an over $1 million dollar prize, a fact he neglects to mention to Bell and Gregson but manages to tell Sherlock once he convinces the Captain to let him speak to him and they head back to walk the crime scene.

Emple is very excited to see Sherlock, and clearly considers him a friend and is surprised to hear he moved to and from England without telling him. Sherlock is very brusque about it.

Walking the scene Joan notes that Sherlock could've handled this himself and obviously had another motive for asking her there. He notes just like she did when asking Kitty for help with her private investigation. Sherlock likes the idea that Watson is trying to reach out and help Kitty. So he asked her to follow the guy for him. He also figures out a clue at the scene: the next problem in the puzzle hunt was painted over after the dead guy got dead, which means that no one else could've used the clue. Emple says most people think the hunt is run by a math organization at Ramapo and he probably knows other players.

They go interview one woman who was playing. She did know the dead guy, a man named Ike, they had teamed up to split the prize-- which is against the rules. She has an alibi though. But she does know at least 16 other people who were in the hunt.

Kitty shows Joan her surveillance photos. She didn't get much. She leaves Joan's abruptly and Joan stops her and says she read the file. Kitty thinks she asked for her help out of pity. Joan says that's not it but that Kitty only seems interested in being a PI. Kitty snarkily calls her out for trying to play counselor like she did to Sherlock. She says what happened to her-- rape and torture apparently-- were just that, things that happened to her and it's in the past and wants to leave it there.

Sherlock calls Joan very early. She's still in bed with her boyfriend. Sherlock correctly deduces she's had sex. But more importantly he and Bell have found another puzzle hunter named Byron, one with a mental illness and previous outbursts of violence. They track him down to a transient hotel. Sherlock hears a noise after they knock on the door and pushes Bell aside shortly before the door explodes with bullets. They chase after him and come up short. But they go through his books in which he was working on the puzzle hunt. They send his scribblings to Emple, they figure if he can figure them out they can figure out where Lowenthal is going next to find the clue.

Kitty puts them up on the wall of the brownstone and Harlan doffs his shirt to start looking them over. He says it's nice to meet another member of Team Sherlock. He says she must not have worked a case like this before because they would've met. She says in England they worked with another mathemetician. He is hurt, thinking he was fired.

Sherlock meets Andrew, Joan's boyfriend, as he's coming out of the bathroom, with no pants on. He is superhot, played by Raza Jaffrey from "Smash." He apologizes for meeting Sherlock this way. Sherlock notes that Joan seems "adequately sexed." He kisses her goodbye. Sherlock calls Joan's home "utterly pleasant" in a critical way saying that when she moved out to make a life of her own he didn't think it would be to be like everyone else's life. The subject is changed to Kitty. Sherlock goes on and on about how they can help her and be like parents. Joan says they are not her parents and Kitty needs real help and to attend some kind of therapy or support group and as the person who brought her here, Sherlock should try harder to help her.

Harlan figures out more clues and that the person running the hunt changed the clues after the first murder. Harlan also figures out where the next spot is. Sherlock knows the man will be dead there. He deduces that the person running the hunt is either some kind of serial killer or, more likely, trying to smoke out a specific puzzle hunter. It's not a treasure hunt, but a trap.

Harlan undone by the second crime scene needs a moment to collect himself at the brownstone. Sherlock explains everything that has happened up to now. They learn that Ramapo isn't sponsoring the game. Sherlock doesn't think it's a serial killer. Harlan thinks it's the government. Sherlock thinks the government would do a better job of disposing bodies.

They go visit another puzzle hunter who thinks he knows who the killer is. He's a wealthy, smarmy guy who has amassed a group in his swanky offices to finish the hunt to find the killer. He made a lot of money in commodities. The guy points to an agitating math blogger who goes by the nom de internet Mo Shellshocker. Harlan has heard of him saying he uses his blog to expose bad math, corrupt economists and pollsters and calls him a crusader. Wealthy guy thinks he's the killer they just need to find the real person behind the blog. Two people who commented negatively on the blog were the two dead guys. Wealthy guy says his workers are going over Mo's math to see if there's a signature.

They leave and Sherlock correctly identifies Harlan as Mo. His blog name is anagram of Sherlock Holmes. Harlan says he never thought he would see it and it was an homage. He says math is misused around the world by bad guys and he decided to do something about it, like Sherlock. Mo/Harlan is wanted by the FBI because he exposed bogus performance stats on a new fighter pilot. He knows he screwed up and says he knows about that he was replaced as Sherlock's expert. Harlan is hurt. Sherlock explains he didn't get anything wrong it was just that Harlan got really needy over time, asking advice on his social life and inviting Sherlock to parties. (The horror!!) .Harlan says he thought they were friends. Sherlock says he was his employer, he was a consultant, one of many. Harlan says that being a math geek made him an outcast and thought he'd made a real connection to Sherlock. He is clearly hurt and angry. He says he got a lot out of the work they did but if Sherlock thinks he's a loser, he must be. He leaves.

Sherlock and Joan Facetime about the case. He just sits there and thinks, to her consternation. They try to work out what the killer wanted since he doesn't seem like a normal serial killer, he clearly wanted something specific. That he was on a puzzle hunt himself. Kitty returns with take out and looks annoyed to see Watson on Sherlock's screen.

Sherlock comes down for dinner and asks Kitty to go to support groups. She acquiesces. And also has an idea about Harlan/Mo and tells Sherlock to take a look at his blog.

Sherlock disguises his voice and calls wealthy douchey guy and appears to give him Harlan/Mo's address.

Sherlock goes to see Harlan, who has been ignoring his text messages. He explains that the killer was looking specifically looking for Mo. And he figured out why. Mo had figured out how a specific lottery scratch tickets could be hacked by looking at it and published his findings.When he did, the Lotto took the game out of circulation. Sherlock looked up to see who had exploited the flaw and won money. Turns out wealthy douchey guy didn't make all his money in commodities, he was a psychopathic lottery cheat who decided to lure Mo into the game and each time he found someone in the puzzle hunt he tried to see if they were Mo and if they weren't, he'd kill him. We see him, with a gun in Mo's building. Fortunately, Sherlock gave him the address of an empty apartment in the building. He busts into the apartment and Bell and Gregson arrest him.

Harlan is now worried wealthy guy will tell police and police will tell FBI and Harlan will be screwed. Sherlock covered his tracks for him, and apologizes for the way he treated him in the way that he does, without saying he's sorry but saying he's a tremendous asset and will need his help in the future.

Joan goes to visit Kitty. She cracked the case. There was a priceless mural in the building painted by Diego Rivera, painted over. The guy they were following was trying to get the building for a song and make money off the recovered mural. Joan says she's leaking the story to the Times so neither of them will get any money since there will be no fee since she has to refund her client. Kitty is fine with that. She tells Joan she's going to a support group that night and, with great pain, asks Joan for her help. They attend the meeting together.