A woman is knitting while hanging out with a friend who is reading something. There is a bullhorn and they run out of their tent and into a store where everyone is trying to get inside. One of the women is trampled.
Jane and Maura discuss how to run the dishwasher, then Maura announces that cousin Carlos is coming. Jane doesn't want him there. Carlo constantly sues people when he falls.
Angela comes in and plans to get rubber mats for the floors. Maura doesn't think he will scam his own family, but Angela does. Jane and Maura are interrupted by a phone call from the cops.
Maura and Jane agree that Maura does not have a dilapidated home. At the crime scene, the victim is named as Helen Barnes, 53. However, she died of being stabbed.
Frankie wonders why someone would stab this lady--was there a sale emergency? Frankie and Nina look at security footage and see a guy who is looking at the woman. They run facial recognition software.
The daughter says that her mother was very good at deals and that there was no animosity in the bargain hunting community. She does not recognize the photo of the suspect.
Frankie ID'd the guy as Elliot Dutton. Nothing helpful in his background. Jane thinks maybe he isn't the killer, but Nina finds out that he is taking a bus out of town.
Frankie approaches and the guy runs off. The guy says his boss wanted to kill him--he mistook Frankie for his boss.
Dutton says he did nothing, but thought his boss was chasing him. He denies killing anybody. His boss attacked him. He starts moving his hand to try to recognize the woman's face.
Jane does not believe that facial recognition blindness is not a real thing. Maura says it is--there's a problem in the brain. Maura says people with the condition find ways to cope. Jane still thinks he's lying. Maura says there are research centers elsewhere, but none are close enough.
Dutton doesn't recognize himself in the photo from the crime scene. He insists he didn't kill the woman.
Jane comes back in wearing a lab coat and is introduced as a doctor. Dutton is given a series of mug shots and recognizes nobody, even though one of them is Vince.
No blood on Dutton's clothes.
Vince says that Dutton's boss was not in the crowd but Jane theorizes that Dutton thought he was stabbing his boss in self-defense when he killed Helen.
They go to Dutton's workplace and find blood on the floor. Coming in with their guns, Jane and Vince find a trail of blood and the place is ransacked. The boss is dead on the floor behind his desk.
Maura says the guy died of five stabbing wounds similar to Helen's. So maybe Dutton thought the killer was his boss, but it was a different person.
Frankie meets a detective Fordham who just transferred here. His phone is buzzing. It's his mother. Angela wants Frankie to go to the house to watch Carlos. He misses his chance with the new detective as a result of the conversation.
Dutton is housed in an assisted living facility to keep him safe for the next 48 hours. The officer puts on his hat so Dutton can recognize him. Dutton fears his boss will attack him again. He is told that someone killed his boss. He asks for a minute before answering questions.
Carlo is talking about how much he loves jazz. He and Maura drink wine together and talk. He tells her he is a trumpeter and music teacher. He had to give up his musical dreams to make a living.
Maura tries to leave, but Carlo needs to use the bathroom and Angela tries to stop him from going anywhere. Maura thinks Angela is overreacting and that maybe Carlo has changed.
Dutton recognizes Jane because one leg is longer than the other. He doesn't think he can help because he doesn't know why someone wanted to kill him or recognize him. He tells her how he often didn't recognize his own mother. He wants to go to Norway but he knows he can't leave his neighborhood because of his condition. He feels guilty about what happened to Helen. He doesn't think anyone would miss him if something happened to him.
Frankie and Nina find records of cash dividends for the company that Elliot works for that have no paper trail. Jane asks him about it. He admits that there were too many cash payouts to the cleaners. He didn't ask about it because he didn't want attention drawn to his condition. He realizes his boss didn't just hire him to be nice--he was using him.
There are now six locations of the store but way too much cash. So perhaps the company is a front for money laundering. One location was burned down right after Helen's murder. It is arson.
Vince and Frankie look at the burned building and find a fried hard drive. Vince finds some embers that might tell them something.
Jane tries to walk evenly and Maura tells her she should get her uneven legs fixed. Maura says everything went fine with Carlo.
Angela gives Maura gelato to thank her for letting her put mats down everywhere. Carlo comes by with his trumpet. He plays taps. Angela puts a mat back.
Carlo plays his trumpet. Jane comes in and rolls her eyes while Angela and Maura are listening. Jane is suspicious. He hugs her. He made Zeppilis for her. Angela says he must be on medication. He brings over the desserts. He goes to get powdered sugar. He slips and falls.
In the lab, Maura tells Jane that Carlo did not call. Anyway, she was able to take photos of the burnt paper to see what is underneath it. It is mainly receipts and pay stubs. Jane notices one is from the IRS. Maura takes the photo and finds that the IRS was auditing the company's financial records.
Vince asks Frankie and Nina for an update. They are investigating a shell company --the owner is connected to a big drug dealer named Spencer Romero, who is likely the killer.
Jane shows a photo of Romero to Elliot but he doesn't recognize it. She plays the video and nothing about his mannerisms is familiar to Elliot. He is putting pressure on himself. Jane encourages him to relax and do what he usually does to recognize people. They play the video again. He recognizes the guy. He has questions about who the guy is. Jane tells him his name but can't tell him anything else. She tells him he's safe but he's not sure because he has to leave after 48 hours.
Vince says Elliot is a poor witness because of his facial recognition problem. Jane thinks maybe they can get Romero on tax evasion and keep Elliot in witness protection while they do it.
Jane goes to see Elliot but he's been in the bathroom a while. She sees a newspaper flapping and grows suspicious. She finds Elliot went out a window in the bathroom. She wants to know what happened. He saw a news article on the guard's phone and ran away.
Nina finds that Elliot has not used any credit cards or ATM machines. Vince says they will keep him in a safe house if they can find him. Jane realizes Elliot still has the bus ticket from earlier.
They rush to the bus station to try to find Elliot. Jane sees a bag with a Norway sticker. She sees Elliot hiding behind a trash can. She tells him they have to get him out but he says he has to leave Boston because he could be anywhere. Elliot is scared but Jane says she can protect him. In the street Elliot recognizes the killer's smell. The killer tries to stab Elliot but Jane stops him. They fight and the guy tries to choke Jane. Elliot screams POLICE STOP and that gives the guy enough of a shock for Jane to punch him.
Carlo comes to the Dirty Robber wearing a neck brace. Jane confronts him about his lawsuits. Carlo insists his neck genuinely hurts and that Maura's insurance will be enough to cover the lawsuit. Maura shows up with a video of Carlo faking his injury. He takes off the neck brace and says he'll see them at Christmas. Maura thinks Carlo is a very talented scam artist. They eat Zeppilis that Maura is carrying around in her purse.