When the social security number of a young prosecutor comes up, Reese and Finch work together to figure out if their person of interest is the victim or perpetrator.

Reese and Finch question the machine's reliability when they are asked to investigate a teenager who was killed years earlier; Finch remembers the origin of the machine.

Reese goes undercover to find the threat surrounding the next person on Finch's list: a young army veteran named Joey Durban.

Reese and Finch get some help from Detective Fusco as they surveil their latest POI, Dr. Megan Tillman, while she’s on call and after hours to unravel the threat surrounding the promising young physician.

Reese and Finch have the added challenge of investigating a Person of Interest who wants nothing to do with their brand of vigilante justice.

Reese becomes romantically involved with the newest Person of Interest: an attractive woman who isn't all that she seems.

The Machine identifies a school teacher who witnessed a mob hit as their next POI and Reese and Finch rush to save his life.

When Reese and Finch discover that their latest POI has connections to Cold War Soviet espionage circles, they quickly learn how covert ops were handled in a world before The Machine.

Reese and Finch’s game of cat and mouse with Detective Carter becomes infinitely more complicated when The Machine declares that she is their newest POI.

As Detective Carter deals with the fallout from her recent encounter with Reese and Finch, The Machine ups the ante for the duo by giving them four Social Security numbers instead of one.

Reese is confined to a wheelchair recovering from his gunshot wound, but Finch sets him up in an apartment where he’s to keep an eye on the Super, who is their latest POI. Also, Finch approaches Carter and gives her a POI to show her what they do.

When Carter finally comes face-to-face with Reese, he urges her to join forces to help with their latest POI, a scrappy young woman from the wrong side of the tracks who turned her life around and became a lawyer.

The Machine gives Reese and Finch the number of a down-and-out man who has been pushed too far, and they're forced to turn to former Person of Interest Zoe Morgan for help.

The Machine identifies Darren, a teenager whose brother was just murdered, as the next POI. Meanwhile, Finch is growing concerned that the son of his former business partner is dangerously close to finding out about the Machine.

Reese discovers there’s more to the story after he infiltrates a smuggling ring to get close to his latest POI.

The Machine leads Reese and Finch to Wall Street when a sharp young trader at a major investment bank becomes embroiled in a multi-million dollar financial scam.

When The Machine spits out the number of a 6-month-old baby, Reese and Finch turn into overly protective parents – with an arsenal at their disposal. Meanwhile, when Elias resurfaces, Detective Carter begins to question her new allegiance with Reese and Finch

The Machine's latest number presents a unique challenge for Reese and Finch since the person has virtually no digital footprint - and appears to be leading a double life.

When The Machine spits out five numbers, naming the Don of each of New York’s crime families, Reese and Finch suspect Elias is planning to eliminate his competition.

Reese goes undercover as an armored car company employee, and faces memories from his past with the CIA.

Finch gives Reese his birthday off so that his partner doesn't have to face a Number that is tied to Reese's past.

The newest POI’s curiosity could spell his doom when he finds himself embroiled in a dark government conspiracy – one that Finch is all too familiar with. Meanwhile, Reese uncovers something revealing about Finch’s past.

As the clock ticks down, Reese winds up trapped with his POI in the most heavily surveilled part of the city, forced to rely on the help of Finch, Carter and Fusco to fend off the FBI, corrupt cops and a slew of old foes.

Reese must protect an investigative journalist through surreptitious means to avoid becoming part of her story.

When the machine names a New York cabdriver as a person of interest, any of his passengers could be a part of the impending crime.

As the FBI pursues "the man in the suit," Reese is even more determined to protect the latest person of interest after learning she is the sister of a soldier who was killed in action.

Finch and Reese head to Atlantic City to protect the latest person of interest, an elderly gambler; Carter tries to clear another detective's name.

When a person of interest is poisoned, Finch and Reese only have 24 hours to identify the toxin and find the person responsible; Detective Fusco's past catches up to him.

The Machine, now completely self-governed with its whereabouts unknown, resumes giving Finch its "irrelevant" numbers for people in danger, which include a U.S. naval officer in town for Fleet Week. However, with so many sailors flooding the streets of New York City, finding the officer in time presents an even bigger challenge for Reese and Shaw.

The number comes up for an Internet entrepreneur in the business of eliminating people's privacy, but finds his own being rapidly stripped away. As his life spirals out of control, Reese tries to protect him while Finch calls on Shaw, Carter and Fusco for help finding whoever is after him.

When the Machine gives the number of Ian Murphy, a man suspected of being a stalker, Reese along with Shaw recruits Carter, Fusco and Zoe to investigate further into his background. But when they discover that Murphy has a son from a former lover who is now dead, they work to reunite the boy with his father and right the wrong set in motion by the boy's grandfather, who wanted Murphy dead after he didn't approve of him and saw him at his daughter's funeral. Meanwhile Root sets her escape plan in motion with the help of the Machine when government operative Hersh tracks her down. Finch arrives at the hospital and finds to his horror the hospital staff incapacitated and Root gone.

The team must figure out if a prominent lawyer orchestrated the murder of her husband or if she is being framed; Carter is spotted with Reese by her new partner.

Shaw must stay close to a 10-year-old girl with highly developed surveillance skills when she is identified by the machine; Carter's mission could be exposed.

After being freed from her confinement to the psych ward, Root needs Shaw's help with a directive from the machine; Finch and Reese look into a mild-mannered investigator.

The team is met with surprises during an investigation into a hypnotherapist; an antiquities dealer has ties to a crime organization.

The machine gives Finch 38 numbers at once; information about Carter's past is revealed.

The battle to bring a crime organization to justice reaches a new level; Reese's number comes up in the machine.

As the POI team seeks justice for Carter’s murder, Finch realizes one of his team members may go one step too far in order to end the war with HR. Also, The Machine gives out the number for NYPD Officer Patrick Simmons, one of the crime organization’s key players.

Flashbacks to Finch’s adolescence provide insight into his creation of The Machine. Also, the team receives the number of an already dying man, and Reese leaves the POI team behind in the aftermath of the war with the crime organization, HR.

Multiple enemies converge on the POI team as they protect a dying man whose number has come up. They struggle to keep their enemies at bay but without Reese, who has left them and their mission behind following the tragic war with HR, being down one man could have catastrophic repercussions for the team.

Reese boards an international flight in an attempt to put the team and the past behind him, but is angered when he realizes his travel plans have been manipulated.

Reese rejoins Finch in New York, but when the team receives the number of a highly skilled antiquities thief, a surprising turn of events finds them planning a heist which could land them all in jail.

Finch goes undercover in an emergency call center to protect a 911 operator, but it soon becomes clear that the threat reaches further than the team could have anticipated.

The secrets of Finch’s operation before he enlisted Reese are revealed, including shocking ties to present-day events.

The Machine assigns Root to seek out a janitor with a mysterious past, but when her very presence puts his life in danger, Finch also receives his number.

Finch and Reese must delve into the murky waters of international politics when they are given the number of a former government contractor who is stalking a UN diplomat. Also, an enemy attempts to gain an upper hand on Root.

Reese and Shaw pose as alumni at a high school reunion in order to keep eyes on the latest POI. Meanwhile, Finch and Fusco travel to Washington, D.C., to investigate the motivations behind Vigilance’s latest attack.

Reese poses as a Secret Service agent to get close to the latest POI, a U.S. congressman who may hold the key to derailing Decima’s plans to bring a second Machine online.

As Decima uses Samaritan’s feeds to hunt Reese and Shaw, Greer exploits Finch’s greatest weakness in an attempt to lure him out of hiding: his love for his former fiancée, Grace Hendricks.

When an unknown entity prevents The Machine from seeing the full picture of an impending catastrophic event, it sends the team five separate numbers to help them piece together the bigger picture. Meanwhile, Root’s team of hackers arrives in New York.

The team takes desperate action in its race to prevent the malevolent AI program Samaritan from coming online and making them its first targets. Meanwhile, the months-long battle with the anti-surveillance terrorist group Vigilance comes to a shocking conclusion.

As Reese and Shaw race to catch up with Finch, he infiltrates a maximum-security government facility in a desperate mission which could mean the end for not only Samaritan, but for himself and The Machine as well.