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 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.

Finch, Reese, Fusco and Shaw embark on one last mission to prevent Samaritan from destroying The Machine and cementing its hold over mankind.

Samaritan launches a cyber-attack on the stock exchange, forcing the team to risk their lives in a desperate mission to stop a global economic catastrophe.

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

Finch and Reese team up with unexpected allies as they race to fix the machine; as Detective Carter tries to apprehend Cal Beecher's murderer, she finds herself up against HR -- a criminal organization.

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.

Finch and Root race to save The Machine, which has been located by the rival AI, Samaritan. Also, Reese is caught in the middle of the final showdown between rival crime bosses Elias and Dominic.

When a virus causes the machine to malfunction, numbers are issued irregularly; the team searches for an extremely elusive tech millionaire.

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

Finch’s number comes up when a fatal error blows his cover identity and sets off a deadly series of escalating encounters with Samaritan’s operatives.

A lethal government operative who tracks and stops terrorist threats before they occur finds herself on the run – and the new focus of Reese and Finch's attention. However, their pursuit proves to be their most formidable when they discover that her remarkable skill set equals their own.

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.

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

Carter tries to help Reese by engaging in mental warfare with the FBI; Reese has encounters with old and new enemies; Detective Fusco must protect supermodel Karolina Kurkova, the latest person of interest.

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.

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.

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 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.

Reese must save Elias from the Brotherhood. He can't get any help from Root or Shaw since Shaw's cover is blown and Root is escorting her to underground.

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.

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 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.

Reese and Fusco get caught in the war between the two newest POIs, rival crime bosses Elias and Dominic. Also, a tantalizing clue to Shaw’s whereabouts leads Finch and Root into a possible trap, and Control goes rogue to uncover the true intentions of the Samaritan program.

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.

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 abducted by a former acquaintance planning a massive and potentially deadly act of cyber-warfare.

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.

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.

While Reese is forced to go to counseling for his violent tendencies, Root, Shaw and Finch try to help a new POI.

Reese finds himself on a dangerous personal journey when he takes on a homicide case Detective Carter was never able to close.

Reese and Finch try to protect a psychologist whose unorthodox methods for helping his patients find closure could cost him dearly. Meanwhile, flashbacks reveal Finch’s fragile state in the days following the bombing that killed his best friend, Nathan Ingram.

Reese and Finch must protect Harper, a street-smart grifter, when her plan to steal cash from a medical marijuana dispensary goes up in smoke.

When the Machine arranges for Finch to sit on the jury of a murder trial, he begins to suspect that a fellow juror is set to rig the proceedings. Meanwhile, Reese begins to open up to the department’s therapist.

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

Reese’s cover could be blown when he realizes the latest POI has ties to his old CIA colleague, Kara Stanton.

Reese must protect a bounty hunter who refuses to allow the potential threat to her life sway her from the relentless pursuit of her target. Also, Finch tries to set the plan he began in Shanghai in motion.

The Machine sends Reese and Finch to a wedding to protect a pair of POIs before their nuptials. Also, Fusco becomes angry at being kept in the dark by the team and takes it upon himself to investigate a string of missing person reports.

When The Machine gives them the number of a mob enforcer whose life becomes endangered, Reese and Finch must decide whether to intervene or allow karma to balance the scales of justice. Meanwhile, Finch seeks aid from an unlikely source.

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.

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.

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.

Reese tries to protect a software programmer with a mysterious second life, but it’s unclear which side of her life the threat is coming from. Meanwhile, Claire, a young hacker whom Finch tried to protect from Samaritan, reaches out to him for aid.

Reese and Finch scramble to protect a software CEO when his behavior becomes increasingly erratic following a hacker attack that reveals all his secrets and unravels 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.

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 goes undercover in an idyllic neighborhood when The Machine’s latest number sends him to the suburbs.

Reese protects an NYPD analyst whose investigation into a software glitch has drawn the attention of Samaritan. Also, Reese and Fusco are threatened by an ally of Elias’s, who is looking to avenge his friend’s death.

Root and Reese investigate a small town in upstate New York that holds the key to Shaw's location... and whether she's dead or alive.

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.

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.

The team is spread thin when a husband and wife’s numbers both come up

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.

Root goes undercover at a radio station to protect the host of a conspiracy theory show who stumbles upon information that could get him killed. Also, Samaritan’s agents try to convince a member of the team that their goals are noble.

As Finch and Reese try to protect six people simultaneously, clues lead them to a coastal town; when a storm forces Finch and Reese to seek shelter in a police station with a group of locals, they realize a killer may be in their midst.

The Machine gives Finch and Reese the number of a brilliant surgeon, but they soon discover that a resourceful third party has raised the stakes for this POI, forcing them to turn to an unlikely source for help.

With Finch back in the Library, Reese returns to field work, only to face his toughest case yet – protecting the privileged daughter of a Brazilian diplomat.

Finch and Reese meet their match: a tech billionaire whose curiosity and endless resources could expose their identities and ruin their efforts to save his life.

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.

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

The Machine experiences a glitch during rebooting, supplying Reese and Fusco with the numbers of dozens of people not actually involved in crimes, while also locking Finch and Root out after identifying them as threats based on past violent behavior.