In Serbia, Charles Harris speaks with a woman Sanja, who tells him that the girl saw everything. Harris promises Sanja that he can keep the girl safe.
Two weeks later, Reese and Finch go to a hotel and check in as new employees. As they dress for work, they discuss their new number, Mira Dobrica, who works as a maid at the hotel. She immigrated to the U.S. in 1999 when computer records were les than thorough, and Finch has contacted Immigration for more info. Reese is working as a bellhop while Finch works a concierge, and they realize that they have their work cut out for them spotting a potential killer among 700 guess.
Derek Fowler, the floor manager, comes over and thanks Finch for filling in on short notice. With him is Bud Garrison, the head doorman. After briefing Finch on an upcoming aviation technology event, Derek orders Reese to get to work. Reese goes up to check on Mira and meets Zoe in the elevator. She compliments him on his new suit and refuses to say why she's there except that she's working a fixer job. Once she gets off, Reese plants a hidden camera on Mira's cart and overhears her nearby arguing with a guest, Tug Brantley. Tug is trying to pay her for sex and Reese uses his key to unlock the door and interrupt him. When Tug threatens to report him to management, Reese threatens to go to the police and Tug, the CEO of an energy drink company, backs down. Mira leaves and Reese goes after her, and she insists that she doesn't need her help. Impressed, Reese tells Finch that he likes her and then clones her phone. Finch gets the report back from Immigration and informs his partner that Mira entered the U.S. as a political refugee from the Kosovo War at the age of 16. Her family was killed in the war and she's been on her own ever since.
As Finch helps the guests at the front desk, he uses his computer to hack into the hotel's surveillance cameras. He spots Derek and Bud meeting with Mira and listens in as Derek warns the maid that the police are asking around about his side operation. Mira insists that she didn't say anything to them and Derek figures that she's telling the truth.
In Washington, the Special Counsel calls Hersh, who admits that it took him awhile to get out of Rikers. The killer assures his superior that he now knows who he's looking for, but the Special Counsel warns him that their source has been compromised since Reese's break-in at the DoD. Hersh explains that he plans to keep an eye on crimes in New York and look for the ones that signify Reese's presence. Once he signs off, Hersh steals a police car, turns on the scanner, and drives off.
Carter is working at the station when Cal Beecher comes to see her. He warns Carter that his mother set him up with a woman she knows from church, but he told her that he's seeing someone else. Cal asks if Carter has told her son Taylor about him and Carter admits that she had. The detective suggests that he and Taylor get together sometime just as SAIC Moss with the FBI comes in. Carter says that they'll talk later and then meets with Moss, who explains that he wants to follow up on Donnelly's recommendation to recruit Carter as a FBI agent. She agrees and Moss says that he'll have to run a polygraph test on her. He offers to do it that night at the station. As they talk, Fusco listens in. Once Moss leaves, Fusco asks his partner if she's going through with it and Carter says that she is.
At the hotel, Reese goes to the concierge's desk and worries that they haven't spotted anything. They do a spot a woman who has been with several different male guests and they figure that Derek is running an escort ring. While Finch calls to have Carter do some research, Derek comes over and complains that Reese is lounging around. As Reese leaves, Carter informs Finch that the vice squad picked up a girl at the hotel on prostitution charges. Bud the doorman posted her bail and the girl refused to testify against her boss. Carter asks Finch about the polygraph test, since he's been listening in on all her conversations, and Finch advises her to try and lie on one of the baseline questions, ruining the rest of the test. He also suggests that she avoid Finch and Reese for the time being.
Mira is in the hallway when Harris comes out of his room and tells her that they need to talk. When Finch spots them together, he checks Harris' room service bill and confirms that he's spent most of his time drinking. Meanwhile, Reese is taking a woman, Betty, to her room. She flirts with him and suggests that he come up later as part of "room service," and Reese quickly leaves. He checks on Mira and hears her arguing with Harris, who wants her to listen to reason. Reese uses his key to enter and finds Harris showing Mira some photos. He quickly puts them away and Reese claims that he came in to check the mini-bar. Harris calls Mira "Miss Brozi" and asks her to think about his offer, but she walks out past Reese. When Reese goes after her, Mira accuses him of keeping an eye on her for Derek. Reese tells the maid that he knows she tipped off the police and that he knows about the floor manager's escort service. Mira tells him to stay out of it, insisting she can do fine on her own.
Reese goes back to the concierge desk to check with Finch, who has run an ID check on Harris. The man is a freelance reporter who writes stories speaking out against dictators. As they talk, Reese spots a man in a turtleneck sweater who has been sitting in the lobby since they arrived. Rees realizes that he has a clear line of sight to the doors and calls Zoe to help them. She comes down, sits next to the man, and spills a drink on him. As soon as he leaves, another man sits down in the same chair, while Finch confirms that two other men have shifted positions. Reese realizes that they're a military recon team using standard tactics and wonders who would send a hit squad to kill a hotel maid.
Once the first man cleans up in his room and goes back downstairs, Reese enters his room, which Finch confirms is registered to a Peter Krief out of Germany. While Reese searches the room and finds files on Harris, Finch hacks the reporter's computer via the hotel wifi and discovers that his current story is about Colonel Rudko Petrovic, a Serbian officer running for prime minister. He's accused of war crimes and Harris was preparing a story confirming Petrovic was guilty. Mira witnessed Petrovic kill her family and they figure that Petrovic sent the hit squad to kill her as soon as they identify her as Harris' witness.
Finch has Fusco come in, sending him a photo of the killers. Meanwhile, the assault team moves back to their original positions and Reese goes to find Mira in the basement. As she leaves for the day, one of the killers comes at her and Reese takes him out. Once he's hidden the unconscious man, Reese tells Mira that he knows who she is and why the killers want her dead. Finch calls to tell Reese that someone has blacked out the cameras near Harris' room and shut off his computer. Reese takes Mira with him to investigate.
At the station, Moss begins questioning Carter, starting with baseline questions. He asks her if she's used marijuana and is surprised when she admits that she did. He admits that nobody ever answers honestly, assuming she's telling the truth, and continues.
Finch tells Reese that Harris has checked out of his room by remote, and Reese enters the room. The reporter is gone but Mira notices that a chair has been moved. Reese moves it and finds bloodstains behind it, and realizes that the hit squad killed the reporter and hastily cleaned up. Mira explains that she managed to escape Kosovo with the help of a neighbor woman, Sanja. Harris got Sanja on the record saying that Mira had seen Petrovic's execution of her family when she was at Sanja's home. Petrovic had Sanja killed two weeks later and is now after Mira. Harris had told Mira to go public and testify to assure her safety, but she refused and now the reporter is dead. Reese tires to work out how the hit squad discovered that Mira was the witness and uses his cell phone to confirm there's a strong electromagnetic presence in the room. Following the static from the phone, Reese finds a bug in the air vent and a cable leading to the neighboring room.
Reese breaks into the room and takes out the killer on duty, and Mira panics and runs for the elevator. She gets in and closes the door just as Reese arrives, and the man in the elevator, another of the killers, blocks the camera and draws a gun on her. He orders her to use her key card to take the elevator cab to the basement. Finch stalls the cab and Reese grabs a fire ax to pry open the door. Fusco arrives in the lobby as Finch confirms that the two killers in the lobby are moving off. One of them takes a large trunk out and Finch tells Fusco to stop them from taking Harris' body outside.
While the killer in the elevator orders Mira to give him the recording Harris made of Sanja's testimony, Reese slides down the cable and opens fire. The killer uses Mira as a shield but Reese shoots past her, wounding the man in the shoulder, and then knocks him out. Mira tells Reese about the disk Harris gave her and explains that she put it in her locker. Reese talks to Finch via the camera and Finch calls Mira on the elevator phone to assure him that he's a friend.
Fusco follows the killers and bumps into another man, who claims that he's looking for the bathroom. After giving him directions, Fusco catches up to the two killers outside and gets the drop on them. As he confirms Harris' corpse is in the trunk, Reese calls to tell him to meet him in the hotel. Fusco says that he'll be there as soon as he calls in the incident.
When Hersh hears Fusco's report on the police scanner, he calls the Special Counsel and tells him that he's closing in on the rogue operative.
Reese tells Mira that a friend will take her to the station house, and the maid admits that she hasn't felt safe for years. When she worries that she fled, leaving her family to die, Reese assures her that she's braver than she thinks. Mira decides to testify against Petrovic and put him away for good, avenging her family. Fusco arrives and Mira thanks Reese for her help. As they leave, Reese tells Finch that it's time to go.
At the station, Carter passes Moss' questions thanks to her earlier lie on the baseline. However, another FBI agent comes in and whispers something to Moss. He then asks Carter if she has a relationship with Cal. When Carter wonders why he's asking, Moss refuses to answer and repeats the question. Carter admits that she's seeing Cal socially and Moss if she knows if he's under any current investigations.
As Reese gets the disk from Mira's locker, Derek comes in and demands to know why he's going through an employee's locker. Reese punches him unconscious and tells Finch that he's heading back to headquarters. However, Hersh gets the drop on Reese and takes his gun and phone.
Out in the squad room, Moss informs Carter that he's rescinding the invitation to join the FBI, but refuses to say why. When Carter refuses to back down, Moss tells her to choose her company more wisely in the future. Meanwhile, Fusco brings Mira in and leaves her in an interrogation room... unaware that the man from the hotel basement who asked for directions has come in, claiming that he was mugged.
Hersh takes Reese to the kitchen and orders the cooks out. Once they leave, he asks Reese who he's working for, shoving him to the floor. Reese grabs a glass pitcher and hits Hersh's gun hand. The two men fight, grabbing knives from the counter. After a few exchanged slices, Reese drives the knife into Hersh and tells him that he has twenty minutes until he bleeds to death. He tells the killer that he can either come after him or get to a hospital. As Reese walks out, he asks Hersh if his employer would show him the same mercy.
Cal talks with Carter with an idea for his meeting with Taylor. Fusco leaves to give them some time alone and Carter tells Cal that it might be too son for him to meet her family. When Cal tries to get an explanation, Carter just says that she needs time and goes to the restroom to freshen up. The killer goes into the interrogation room with a garrote and tries to strangle Mira, but Fusco and Carter return in time for Carter to shoot him.
Later, Finch and Rese go to the hotel bar to watch the news. As Petrovic's arrest is broadcast, Zoe comes in and tells them that her job is finished. She's happy to hear that Derek confessed to his escort ring, since her clients want her to make sure that their names don't come out. Reese tells Zoe that Finch has bought the hotel and appointed a new floor manager to make sure everything runs smoothly. Mira, the floor manager, comes in to greet them and says that the drinks are on the house. She leaves with Finch and Reese suggests that Zoe might stay around and take a job. She admits that she's a freelancer like him and Reese admits that he's going to stick around for one more night. When Zoe suggests that they get a room, Reese tells her that he knows the owner and he already has a penthouse suite.
Hersh calls the Special Counsel in Washington and tells him that he's on the way. He then unplugs his IV line and walks out of the hospital. Meanwhile, the Special Counsel calls in his secretary, Ms. May, to have her draft a letter. Ms. May comes in... it's Root, who has his suit for a party. The Special Counsel admits that in the two months since she started working for him, she's made herself indispensable.