The episode begins with Holmes having a phone conversation with Moriarty, and Watson recording the conversation. Moriarty thanks Holmes for passing on his messages to Moran. He tells Holmes that people come to him with various jobs, and he gets it done for them. Holmes is not interested in what he does. The only thing Holmes wants to know is whether he (Moriarty) killed Irene Adler. Moriarty tells him that he is aware that this question has been haunting him for years. He tells Holmes that he will answer her only if Holmes helps him with a case. He wants to hire Holmes as an investigator.
He tells Holmes that a man named Wallace Rourke, was killed several months ago and the New York Police Department failed. He wants Holmes to bring Wallace’s killer to justice, and in return he will tell Holmes the truth about Irene Adler. Holmes immediately gets to work and finds out that Wallace was a mechanic, who was stabbed to death in an ally in Brooklyn. He has also figured out the “Moriarty” is a man from Sussex, 40-45 years old, and also has some connection with Wallace. He tells Watson that if he takes up this case, he would learn more about Moriarty. At the precinct, Gregson talks to Watson and tells her that he wants her to be a sober companion for one of his friend’s daughter.
Watson tells him that she is working with Holmes, but she can give him some other names. Watson and Holmes go to meet Eileen Rourke, Wallace’s wife. Holmes asks her if Wallace worked for some British guy. She tells him that she doesn’t know. She says that few weeks before Wallace died, he felt that he was being followed, but the cops did not take him seriously. She says that Wallace saw the same car following him to several places. Watson tells Eileen that they want t o go through Wallace’s things. Watson notices Wallace’s phone, but she also remembers reading in the police report that Wallace phone was stolen.
Eileen tells her that few weeks before Wallace died, a man bumped into him and poured coffee over his phone. So he had to buy a new one; and the new one was stolen. At home, Holmes goes through Wallace’s financial records and learns that they were not doing all that well. He tells Watson that it is possible that Wallace worked for Moriarty, but he did something less risky because of which he wasn’t paid as much as Moran or Gottlieb. Holmes also thinks that it could be possible that Wallace was good at hiding his money. Watson goes through the coroner’s reports and tells Holmes that Wallace was motionless when he was stabbed.
Holmes finds that a little weird because Wallace was a former Army Ranger and his combat skills were great. Holmes looks at the pictures and learns that Wallace was immobilized first, and then stabbed in both his lungs. Watson asks Holmes about Irene. He is all praises for Irene and tells Watson that she was “the” woman for him. She was the only woman he loved. Holmes then finds out that Wallace was right about being followed. He proves that the person who was following Wallace, was the one who supplied Wallace his new phone. Holmes states that the best way of tracking someone down is by following the cell phone though the identification number.
They now need to find out as to who supplied the new phone. The next morning, Holmes and Watson go to Sutter Risk Management firm, and meet Darren and Katie Sutter. Holmes asks Darren as to why was his firm tracking Wallace Rourke. He tells Darren that it was his firm that sent the replacement phone. Darren admits that they were surveilling Wallace for a brief period of time. He says that Wallace had made some threats against a client, but after a brief period they realized that the claims were not founded, and so they stopped. Darren does not reveal the name of the client. On their way out, Holmes tells Watson that the story that Darren told them was made up.
He shows her the book written by Darren Sutter, and tells her that the book literally explains Wallace’s murder. Watson tells him that the book was written five years ago. Holmes tells Watson that Darren’s older sister, Leah, was brutally murdered. The police ruled the murder as a part of a home invasion robbery. Darren came face to face with the fleeing culprit and helped the police generate a sketch. The sister’s killer was Wallace Rourke, but Wallace was never found. Darren wanted to find his sister’s killer, and that is why he got into security. So, Wallace killed Darren’s sister, and Darren killed Wallace. Watson wonders what Moriarty has to do with all this.
Holmes tells her that maybe Moriarty wants to bring down Darren because Darren’s security firm is one of the best. With Darren removed, his clients would become more vulnerable; and maybe Moriarty wants to get rid of one of them. The next morning, Holmes meets Darren and tells him that he knows about the murder. He asks Darren if he knows Moriarty. Darren says no. Holmes tells him that he needs a list of his clients. He explains why he needs the list. He also tells Darren that it is possible that Moriarty has bugged his place. He leaves. At the precinct, Gregson tells Watson that she should stop working for Holmes because it could put her life in danger.
Bell arrives and tells Gregson that Darren has confessed to killing Wallace. Holmes figures out that Darren found Moriarty’s bugs in his house and office. At home, Holmes receives a call from Moriarty. He tells Holmes that his work is not yet over. Moriarty tells him that Darren killed the wrong guy because Wallace wasn’t the one who murdered Leah. Moriarty tells him that Wallace was in Saudi Arabia when the murder took place. He tells Holmes to finish his job. Next, Holmes finds information that “suggests” that Wallace was in Saudi Arabia when the murder took place, but it is not definite. He tells Watson that there were some prints found on the door, which were never identified.
He goes to Darren and explains things to him. Darren refuses to tell him about his enemies. Watson talks to Katie and tries to convince her to give her the names of her clients. Katie tells her that she cannot. At home, Holmes is frustrated that he isn’t able to solve this case. He is also pissed about the fact that he will not find his answers regarding Irene’s death. Watson has a theory. She feels that Katie must have tricked Darren into killing Wallace so that he could finally find some peace in his life. The next morning, Gregson, Bell, Holmes and Watson go to meet Katie. It turns out that Katie knew Darren before his sister’s death.
At that time, she was married to another man, and was having a secret affair with Darren. On the night of the murder, it was Katie who saw the killer, but she couldn’t tell this out because it would have revealed the affair. It was her prints that were found on the door. Katie was the one who described the killer to Darren, and Darren told the cops that he was the one who saw the killer. The killer wasn’t found, and that was hard on Darren. Twenty two years when Katie saw a guy (Wallace), who she could pass off as an older version of the sketch, she pointed Darren towards Wallace. Katie tells them that Leah’s death had shattered Darren and he also tried killing himself because he could not find the killer.
She was left with no choice. Bell arrests Katie. Case Closed. Holmes goes to meet Darren and reveals the news to him. Later, Moriarty calls Holmes and tells him that he did a good job. Holmes wants his answers. Moriarty tells Holmes that he can either decide to walk away from all this and that they would never cross paths again, or he could have his answers. Moriarty messages Holmes the address where he could find his answers. Watson calls Holmes and asks him if he heard from Moriarty. Holmes lies, he says no. Holmes goes to the address. Watson also arrives at the address.
She knows that Holmes lied to her to protect her. She told Holmes that she knew he would do something like this, and hence she tracked his phone. She tells him that she has been with him all this while, and she too deserves to know the answers. They go into the house. Holmes is shocked to see Irene Adler in the house. The episode ends.