Bell is back at the precinct, but he's using his left hand. Watson brings him dinner. He says therapy is helping but no one can tell him if the damage is permanent. Watson asks if he needs to talk to someone, he says he needs to talk less.
Sherlock is breaking into a car with Alfredo, but he sets it off, then gets angry and kicks it. Alfredo reveals he was able to break into it and knows Sherlock is distracted by what happened to Bell. Sherlock knows that he did everything right, but still can't move on. NAME suggests they go to a meeting, Sherlock refuses and Alfredo insists they will go the next day.
Hauser is a man accused of running a pyramid scheme, thanks to a journalist named Nunez. Hauser watches the news report about himself and attempts to take his own life, but is stopped by someone shooting him in both knees. The shooter says he wants to talk, but his personal chef comes home to find him dead and the word "Thief" written in blood on the wall.
At the crime scene, Watson seems to know the chef. Sherlock examines the body and deduces exactly what happened using bourbon and gun oil as clues. Watson and Sherlock head home and Sherlock announces he wants to start their investigation with the chef. Sherlock asks how Bell is doing.
Watson gets a text from someone and it turns out to be the chef, Chloe, who is a former client of hers. Watson asks for permission to tell her partner because he has listed her as a suspect. Back at the precinct, Watson tells Sherlock who Chloe is and that she was with her sponsor at the time of the murder. Sherlock is mildly surprised that he didn't notice another addict or that Watson was hiding something from him.
Chloe leads them to a Jacob Weiss, who had dinner with Hauser before he died. Weiss says he has an alibi and that Hauser was his friend. While there Sherlock gets a call from the journalist, Nunez' phone, but it is a detective on the line. Nunez has been found murdered.
At the new crime scene, Gregson reveals Nunez was killed with the same weapon and just hours after Hauser. Sherlock discovers sap on the door the killer kicked in and traces it to a specific park. Alfredo calls Sherlock to remind him to go to the meeting, but he ignores the call. Watson volunteers to talk to the kids in the park and sends him off to meet Alfredo.
At Alfredo's, Sherlock meets Randy. Alfredo says Randy is looking for a sponsor and thinks Sherlock is the man for the job. Alfredo hypothesizes that Sherlock is starting to feel empathy after what happened to Bell and since Sherlock can't help Bell, Alfredo suggests he helps someone else. Sherlock argues his work is all-consuming and runs off back to the case.
Back home Watson is watching videos the skate boarders took in the park. He shares Alfredo's suggestion and she agrees. Watson spots a man in one of the videos that she knows, he is connected to Chloe. She meets with Chloe and the man, Maddox, was a man she was seeing when she was using. She dumped him after she got out of rehab, but he was a friend of Hauser's. Chloe tells Watson she can't tell anyone because she's in a custody battle for her son and no one knows she was an addict. Since Watson signed a confidentiality agreement, she is bound to secrecy and must find another connection between Maddox and Hauser.
Sherlock isn't happy they have to hide Chloe's connection, but Watson is adamant. He suggests they tell Gregson anyway and lie to Chloe, but Watson points out it was exactly that sort of thinking that got Bell shot. Later, Alfredo is asleep when he finds Sherlock has broken into his home, and into the car. Sherlock starts talking and admits he's always had compassion for victims and it's never been a detriment to his work, but lately it has been. Sherlock is nervous at the idea of being a sponsor and Alfredo reminds him he's gotten a lot out of the program and it might be time to give some back.
At home, Watson and Sherlock find out that someone recognized Maddox in the video and show a picture to Weiss, who thinks the man was someone who donated paintings for a charity auction. Watson traces that back to an art gallery, but the manager doesn't recognize Maddox. They realize the woman was lying and take a peek around the gallery. Sherlock finds evidence that someone was dragged across the floor. They follow the marks to a dumpster and find Maddox's body.
Gregson follows the evidence and finds out Maddox had money in the gallery, which was a client of Hauser's. They know why Maddox killed Hauser, but not who killed Maddox and why Maddox killed Nunez. Sherlock notices that the gallery is a money-laundering front. Sherlock and Watson bring Gregson to see Weiss, who they have discovered has been claiming money for holocaust victims, but keeping it for himself. They also know that Hauser was planning to reveal what happened, which is why he killed Hauser.
At the precinct, Bell meets the Deputy Commissioner, who offers Bell a job.
Back home, Sherlock nervously awaits Randy. After a long silence, Sherlock admits he does want to be Randy's sponsor. He admits he chose Alfredo on a whim and had very low expectations, but was wrong. Sherlock admits that Alfredo taught him to get the most out of the program and never coddled him, and therefore will never coddle Randy. Sherlock asks if his terms are acceptable and Randy agrees.