In Crown Heights, a gated community in Marlon, Ohio, District Attorney Terry Graham comes out to get his paper... and screams that he's burning up. Artie gets the report and briefs Myka, explaining that Terry died of several symptoms, apparently the result of poison. Pete is off getting his physical and Steven is moving in his belongings from his mother's. Myka takes off to catch her flight, while Steven and Artie smell Abigail cooking. They go to check it out and she explains that she's brought in her own breakfast. Abigail offers to share if they do the dishes, just as Claudia comes in looking for scones. Artie tells her that a 15-year-old boy in New York City, Nick Powell, graffitied advanced math on the wall. Steven offers to stay and help Abigail clean out the neutralizer, and Artie eager agrees to go with Claudia.
In Marlon, Pete and Myka pull up to the gated community. Pete is busy exercising his grip strength and insists that it's the first to go. They talk to the security guard, Rex, who eagerly recognizes them as Secret Service agents and assures them that he's available for backup. The agents drive to Terry's house and Colonel Arnold Cassel, President of the Board, pulls up. He tells them to park in the visitor's parking and Pete is eager to take him on. Myka stops his partner and they park in the visitor parking. As they go to the house, Myka wonders if Pete learned something at his physical. Pete admits that his testosterone is a bit low and worries that he's losing his sex drive and suffering from erectile dysfunction. Janice Malloy, a local woman, comes over and figures that they're there to investigate Terry's death. She tells them that Terry forgot to park his car in his garage and somebody broke his windshield. Janice gives them directions and wishes them luck.
At the warehouse, Abigail puts on a full protective suit, telling Steven that she isn't taking any chances. They go into the neutralizer vault and smell something rotten.
In New York City, Artie and Claudia check out the graffiti and confirm that Nick was in a trance and was radiating light when he wrote the math. Nick is at the hospital getting a MRI, and a local homeless man explains that Nick lives on the streets.
Pete and Myka talk to Terry's stepson, Rodge. He insists that he wasn't there when the windshield was broken, and claims he doesn't know anything was going on. Myka points out that Terry has sent six men to Death Row and Rodge is impressed that his stepfather may have been murdered. The agents receive a forensic report confirming that Terry had several lethal injection drugs in his bloodstream, and Myka calls to have Steven look into Terry's six death row cases. Pete hears a siren and runs to investigate, and discovers that a neighbor couple have merged together at the chest.
Pete interviews the couple and learns that the teenage boy, Spencer, is home alone while his parents are in Miami. He was working with the neighbor woman, Leslie Labelle, helping her make a web site for her candle shop. Neither one of them have handled any artifacts, but Leslie's husband Gerry worked at Terry's office before he was fired. Pete calls Myka and tells her that Spencer was having an affair with Gerry's wife, and Terry fired Gerry. They figure Gerry was involved but have no idea what artifact could account for both cases.
Abigail and Steven work on the neutralizer vault and relieve the pressure. As they work, Abigail asks Steven why he really stayed and the agent admits that he's finally settled in permanently. Steven is worried that since they haven't found anyone to be with, he doesn't hold out much hope for himself. A pipe suddenly gives out, dumping goo in Steve's face. He tells Abigail that he's fine and goes off to take a shower.
At the hospital, Claudia and Artie discover that Nick has been writing more formula on the windows. She assures him that he's not crazy and that she knows what he's going through because she was in foster care and spent time on the streets. Claudia assures Nick that they handle the unexplainable but he needs to talk to her. Nick describes how he gets visions and then loses control of his body. Artie calls Claudia out and tells her that the MRI shows that Nick is having seizures ten times stronger than an epileptic seizure, and if they continue then they'll kill the boy.
Rex informs Pete and Myka that Gerry has returned home. They knock at the door and get no answer, and go in and find him in the garage. He takes a swings at Pete, who easily subdues him and demands to know where the artifact is. Gerry explains that he broke the windshield but doesn't know anything about an artifact. He appears surprised that Leslie is having an affair. As they talk, Rex suddenly bursts into green flame. Even after they smother the flames, they continue burning and Myka finally puts it out with a fire extinguisher.
As the EMTs take Rex away, the agents try to work out the connection between the three attacks. They talk to Janice and confirm that Rex has worked there for eight years. As they talk, Pete eats some of her chocolate cookies. Janice mentions that Rex's condo burned down three months ago, and he lived in the rec center while the insurance company settled.
Once he cleans up, Steven goes to the office and finds Abigail there. She assures him that the Regents brought him there to help with the team's psychological issues. Steven quickly realizes that she's lying about why she quit, and Abigail explains that two years ago she had a patient she couldn't help. She traveled the world taking photographs, met Kosan, and he referred her to the warehouse. Abigail suggests that Steven might have found his own place and four people to be his one, and now he's worried about sharing himself with them.
Artie and Claudia take Nick to an old NSA safehouse and Artie discovers that the equations don't solve anything. Claudia notices that Nick has a medallion for St. Jude, the patron of lost causes, and she neutralizes it. She starts to tell Nick about how a guy recently killed her friend. However, Artie interrupts and tells them that Nick is performing quantitative analysis like banks use. Nick goes into a trance and starts writing more formulae, and Claudia tries to get Nick to describe where his mind is. Nick describes seeing a man's hands writing out what he's writing. The teenager starts to have a seizure and Claudia reluctantly convinces, getting a description of an office. Nick collapses and Artie uses Stalin's sleep mask on him to render him unconscious.
Pete and Myka go to the rec center and notice that none of Rex's electronics stored there were damaged in the fire. Myka finds a secondary investigation report showing that traces of boric acid were found in the power outlets. Boric acid burns green and they figure that it's related to Rex's burns. The agents figure that Rex set up the fire to cash in on the insurance. In each case the agents figure that someone was getting revenge on people who had sinned, and Pete suggests Cassel.
The agents go to Cassel's house and get no answer. They break into his house and find Cassel in his study, coughing up red gas. Once they get him outside, they call the EMTs while Cassel says that somebody knows what he's done. The colonel finally admits that in Kuwait in 1991, his unit used poison gas on an entire village that was harboring terrorists. Myka asks him if someone in Crown Heights knows, but Cassel says that he isn't aware of anyone. The EMTs arrive and tend to him, while the agents watch as the residents start to panic.
Artie examines Nick and warns that he can't survive another seizure. They check with Steve, who tries to work out where the quant is that needs the numerical models. Abigail suggests that the artifact is drawing on a young, flexible brain that can make the connections. Claudia finds one investment firm that matches Nick's description. Nick wakes up and confirms that the firm was the one he saw.
Pete and Myka check in with Steve and Abigail, who find a salt-covered artifact related to Sodom and Gomorrah. Pete works out the connection and realizes that all of the victims are community board members. The last resident is John Foster and Pete goes to check on him, while Myka goes through the board's minutes looking for clues.
That night, Artie breaks into the Armstrong Investment firm. Nick goes into another trance and starts writing formula, and Claudia has him describe what he's seeing. He explains that he's in the same office as before and describes music from a cartoon. Artie realizes that he's referring to "Ride of the Valkyries" and storms into an office. A broker is there, wearing Orville Wright's aviator goggles, and Artie tells him that's he's killing a boy when he uses them. Artie neutralizes them, saving Nick just in time.
Pete breaks into Foster's home, while Myka calls to tell him that the board rejected a request by Janice to put up a bust of her husband, the founder of Crown Heights. Rex spoke against the bust, saying it would tempt vandals. As they talk, Myka realizes that Janice's chocolate chip cookies were at each house... and Pete ate them earlier. She tells Pete that the salt from Sodom and Gomorrah was imbued with magical power, and Janice put the salt in the cookies. As Pete realizes what that means, an unseen force suddenly throws him out the window. Myka runs to his partner and discovers that his legs are broken.
Myka runs to Janice's house and discovers that she's offering cookies to Foster. The agent stops him from eating them and discovers that the artifact is a mask made of salt. Janice grabs a knife and insists that her whole marriage was about Crown Heights, and her husband gave his life for it. Myka disarms her, grabs the mask, and bags it. However, when she checks on Pete she discovers that his legs are still broken. Cassel arrives and explains that he started recovering after he left the community. Myka realizes that Cassel was cured because he confessed, and tells Pete that he has to confess to whatever he did. Pete finally explains that when he was drinking, he was in an accident. He walked away without a scratch, but his friend Dave was crippled. After that, Pete swore never to drink again. Pete's legs start to heal and Myka assures him that he's a completely different person since then.
At the safehouse, Claudia tells Nick that he won't have any more seizures. The teenager confirms that Claudia isn't going to call Social Services, and she invites him back to South Dakota with them so they can monitor the residual effects of the artifact. Nick is skeptical but Claudia tells him that she'd like the chance to pay forward what someone did for her. Artie, listening in, smiles as Nick agrees.
Later at the B&B, Abigail is putting up photographs from her travels. Steven figures that she's taking her own advice about sharing. The teams return and Claudia introduces Nick to the others. Steve is cooking supper and Claudia takes Nick to his new room. The agents say that the case in Ohio was nothing unusual, and they all insist that Abigail leave her photo in the main room.
Upstairs, Nick watches everyone, and then sends a text message to Charlotte saying that he's in.
Later, Myka goes to the hospital and confirms that she has ovarian cancer.