Reese goes to an address and Finch tells him that they have a repeat number. Leon comes flying out of a window and greets Reese, and two men come out. Reese asks them to let it slide but the men keep coming, and Leon explains that he's been running online game gold-farming and the Russian mob is involved. After he takes out the mobsters, Reese takes Leon to the library. The accountant realizes that Finch is the boss and they explain that they have another Number to deal with. Since the Mob is still after Leon, they tell him to stay there while they deal with it, and warn him that Bear will kill him if he touches the computer. As they go, Finch tells Reese that they're heading for a hospital.
Reese and Finch arrive at the hospital after Finch donates money for a new wing. The administrator, Sebastian Alta, shows them around and introduces them to Dr. Madeline Enright, their leading cardiologist and trauma surgeon. As they talk, Finch puts a pair of glasses down on a nearby chair. Madeleine greets them and tries to find her glasses, and Finch points out the pair he put down. She puts them down, unaware that Finch has hid a bug in them. Sebastian explains that they're closing off the floor for a sensitive surgery and says that it's for the safety of the patient.
Madeleine takes energy CEO Oliver Veldt and his assistant Leland Rains, to the operating room. She explains how his coronary bypass procedure will go and Leland reminds her that she's signed non-disclosure agreements because they don't want anyone learning that Veldt is undergoing surgery. She gets word of a shooting victim, a member of an Albanian gang, who has been brought into the ER. Madeleine goes to check on him, shouting down the gang members that have come in. As they take the gang member away, Finch admits that they have no idea who might be coming after her.
Later, Madeleine is getting coffee when her wife Amy comes by with coffee. Reese watches her and Finch confirms that Amy is a charity director. Amy and Madeleine talk briefly about Veldt and Amy says that she'll see Madeleine later.
Fusco is called to an execution-style shooting and confirms that the killer took everything from the victim except for Carter's card. He calls Carter and tells her what he's discovered.
Madeleine goes back to her office and finds a man waiting for her. He introduces himself as Alistair Wesley and says that he wants to discuss Oliver Veldt. Alistair takes out a datapad and shows Madeleine that he has a marksman with a bead on Amy. If Madeleine doesn't make sure that Veldt dies, Amy will die. Finch and Reese listen in as Alistair gives Madeleine precise instructions on how to kill Veldt. He assures Madeleine that if anyone else gets involved or she doesn't do what she's dead, Amy will die. Reese figures that they need to get to Madeleine past Veldt's security. Finch volunteers to stay there while Reese tracks down Amy.
Carter arrives at the crime scene and they go over the footage of the shooting. The dead man is Dusan Babic and Carter has never heard of him. There's a number, 6611th, written on the back of Carter's card and Fusco tells her to get out before people start asking questions.
Madeleine checks on Veldt and warns him that no surgery is without risk. He reminds her that he's paying well for her not to make mistakes. As he's taken away, Leland asks about the procedure and Madeleine assures her that she's using the best procedure. Alistair sends her a text message telling tells her to undertake step one: administer the anticoagulant. She goes to the drug cabinet and gets the drug.
Finch goes to Madeleine's office and checks her computer. Meanwhile, Reese finds Amy at the park where she's running a charity event. He tries to spot the sniper while Finch admits that he can't determine Alistair's identity while he's stuck at the hospital. Finch accesses the video feed and sends Reese the image so he can spot the sniper. At the same time, the programmer hacks the hospital's records and feeds in a shortage of Veldt's blood type so they can stall the surgery.
Reese determines the sniper's location and goes in. He attacks the man and after a brief struggle, shoots him with his own rifle. The man is wearing ballistic armor which protects him and has disposed of all clues to his identity. Alistair calls on the sniper's cell phone and Reese takes the call. He offers to buy Reese a drink and warns that Amy will die if he refuses. Reese figures that he's eliminated the threat... until Alistair has his other snipers call off. Alistair gives Reese directions to a pub and signs off, and Reese tells Finch that he's going to have a drink.
At the station, Carter goes over Babic's file to figure out why he would have her card. Babic worked in janitorial and did a lot of work for tech companies. One company is at 66 11th Avenue and she realizes the number on the card refers to that.
Reese calls Fusco in and tells him to keep an eye on Amy. He tells Fusco that he's getting a drink and goes to the pub. Reese warns Finch that they're dealing with a professional team, and Finch calls Leon to find out who would target Veldt and following the money trail. Leon points out that Bear won't let him near the keyboard and Finch talks to Bear on the speakerphone, giving him a command in Dutch to stand down. Leon goes to work and Finch warns him not to test the limits of his system.
Reese enters the pub and joins Alistair at the bar. He draws a gun on the Englishman and points out that it's for the sentry that Alistair has placed at the door. Alistair assures Reese that there's several people close enough to kill Amy and suggests that Reese have a drink. Reese identifies Alistair as former MI-6 and his men as ex-SAS, and Alistair tags Reese as ex-CIA. He doesn't care why Reese is protecting Veldt and tells him to stay out of it. Reese draws a gun on him but discovers that the sentry has come up behind him. The man tries to garrote him but Reese shoots him in the foot. However, by the time he recovers, Alistair has slipped out the door.
Madeleine goes to the OR and prepares the syringe with the anticoagulant. Amy calls with a good luck message as Finch comes in. He says that he knows what is happening to her and asks Madeleine to trust him. When she wonders why she should trust him, Finch explains that he set up the delay and assures her that they'll save Amy before Madeleine has to make an incision. The assisting nurse, Liz Picket, comes in and updates Madeleine on the delay, and Madeleine says that Finch is a backup surgeon that she called in. Before she goes, Madeleine begs Finch to help her save Amy. Finch calls Reese, who says that Alistair has his own cameras and has the park monitored. There's no way he can pick Alistair's men out of the crowd in time.
Madeleine goes to work and administers the anticoagulant as Finch looks on. With time running out, he calls to warn Reese. Leon calls to tell Finch that he's hacked Veldt's company servers and found a multi-million dollar proposal for offshore wind farms. Veldt refused to take the proposal and Leon has discovered that someone has been short-selling Veldt stock. If the company fails big then the investor will make a fortune. Leon has found an active server for the sales and tells Finch that he'll keep digging.
Finch goes to the ER and whispers an assurance to Madeleine. She says that she's going to take a short break and tells Liz to monitor Veldt's vitals. Once they're alone, Finch tells Madeleine that Reese is close to saving Amy. Madeleine asks for a minute alone and steps into the hallway, and Alistair calls to ask her why she stopped. He connects her to Amy to provide motivation and they chat about the charity. Madeleine says that she just wanted to hear her voice and everything's fine. She tells Amy that she loves her and signs off.
Finch calls Reese and tells him that Alistair knew that Amy left the OR within a minute. Reese realizes that they have no choice and he's getting Amy out.
Carter goes to Fujima and discovers that there was a shooting in the clean room. As she talks to the security man, Carter sees Agent Snow leave. She follows him as he ducks into a nearby building.
Reese tells Fusco to create a diversion. Fusco approaches a cop and picks a fight, demanding his name and badge. Everyone in the park watches them, including Alistair and Amy, and Reese slips a cell phone into Amy's purse.
Leon calls Finch back and says that he hacked the server and found medical file signed by Veldt. Finch realizes someone on the inside told Alistair about Veldt's surgery and tells Leon to send him everything he's dug up.
Reese calls Amy on the cell phone and tells her that he knows all about her and Madeleine. He warns Amy that she's in danger and tells her to stay on the phone and listen to him as he directs her out of the park. Finch calls Reese and warns that Amy will be nicking Veldt's artery in two minutes.
Carter follows Snow into the access tunnels and orders him to freeze. He tells Carter that there's no signal and the woman running him can't hear him. Carter realizes that Snow killed Babic to get the ID so he could break into Fujima. He tells Carter that something big is going down and "she" won't stop. When she wonders why he killed a man, Snow reveals that he's wearing a bomb vest. Before he can explain further, someone opens fire, shooting out the light. Carter loses track of Snow in the darkness.
Finch sits down next to Leland and tells him not to contact Alistair. He shows the man the records of the short sales and the confidential medical information that Leland shared with Alistair. Leland says that he has no idea what he's talking about and they're going to reexamine the wind farm project once Veldt is out of surgery. Finch realizes that he's telling the truth and wonders who leaked the surgery. He goes back into the OR and Madeleine says that she's calling off the surgery and orders everyone out of the room. Alistair, listening in, looks over and discovers that Amy is gone. Reese gives Amy directions out of the park while Alistair calls his men and tells them to remove the target.
Liz insists on staying with Madeleine to close up Veldt. She asks Finch to get her some anesthesia so they can keep Veldt under.
Alistair's men report in that Amy is off the grid. They spread out and one of them spots Amy, and Reese takes him out and escorts her out. Meanwhile, Fusco leaves the park and tells the other beat cop to apologize on behalf of his partner. The man says that he doesn't have a partner.
Reese and Amy get to the car but the fake cop is waiting for them and draws a gun.
Veldt crashes and Madeleine realizes that his artery is nicked... and Liz is responsible. Liz says that she was the backup plan.
As the fake cop draws his gun, Fusco comes running up and distracts him long enough for Reese to take him out.
Liz tells Madeleine to let Veldt die but the surgeon refuses. As Liz goes for a scalpel, Finch comes back and knocks her out with an overhead light.
Reese tells Fusco to stay with Amy and goes back to the park. He finds Alistair's datapad, shattered and resting on a bench, but no sign of the Englishman.
Madeleine gives Veldt a coagulant and tells Finch that she'll have to open Veldt up and will need Finch's help. A nervous Finch assists as Madeleine starts up Veldt's heart from the inside. As Finch tries to avoid vomiting, Madeleine starts up the heart.
Later, Reese brings Amy to the hospital and the couple is reunited.
Finch and Reese put a hood on Leon and drop him off. Reese gives him a paper showing that Veldt survived. All of the conspirators will take a loss and Leon realizes that they won. Finch tells him to keep that in mind and stay out of trouble. As he takes a taxi away, the sniper's phone rings. Alistair congratulates Reese, who points out that Alistair is no more than a common thief. The Englishman realized that they met before in Istanbul at a market. Reese doesn't remember him but Alistair says that's how he was trained. He suggests they get a drink sometime later, hangs up, and takes a taxi to the airport.
Later, Carter meets with Reese and shows him Snow's security badge. She figures that someone is holding Snow on a string and tells Reese that "she" is planning something. Carter wonders what it's about... and if Reese would tell her if he did. He refuses, saying that he can't stop her from looking into it. Reese points out that she still has her son and suggests that she consider how much she really wants to know.