Sam Shaw and her associate Michael Cole receive the Relevant numbers from the Machine.

Finch goes undercover at a tech company to watch a rising VP. The company appears to be riddled with agents who are a front for something more sinister. Shaw reappears and takes an interest in Root. HR decides to rub out an informant.

They wait ten days for a new number due to a system virus, suspecting Root is the problem. It's for Ernest Thornhill, who isn't who, or what, he is supposed to be. At stake is The Machine - will it remain with Finch or end up with Decima?

Reese and Finch team up with surprising allies in a race to save The Machine from Root and the mysterious international organization, Decima, who have both re-emerged with dangerous agendas.

It's Fleet Week in New York City, making the hunt for one Naval Officer among a sea of sailors even more difficult for Reese, Finch and Shaw.

The head of an Internet company ostensibly for finding lost loved ones is really a front for selling personal info. Carter has to train a new cop while she looks for Beecher's killer and a new vigilante named Collier makes his appearance.

The team suspects the latest number to be a potential stalker/ killer until he's nearly shot on the street. Root plots her escape from the institution and gives her psychiatrist a big surprise.

The next number the machine dispenses is for Vanessa Watkins, a hard-nosed prosecuting attorney who, when Finch and Reese first meet her, has just reported her husband, Jeremy Watkins, missing from their yacht. While Vanessa has put away many a criminal over her storied career, Jeremy has let many go as a flashy and high-priced defense attorney. As her number came in after the report of him missing, they know Jeremy's presumed death is not the reason for the number, yet they don't know if Vanessa is the target or the perpetrator. They learn that the lead investigator on the case of Jeremy's death, Detective Cameron, is looking at her for her husband's murder as all evidence found thus far implicates her. Cameron's main problem?: he doesn't have a body, and thus needs Vanessa to confess to make a conviction stick, which she may or may not know. They will also learn that Cameron has a personal vendetta against her, which places a major obstacle in tracking her as she tries to elude Cameron. As Finch and the team wade through the story of the complicated lives of Jeremy and Vanessa - including their unlikely personal coupling - they find that Vanessa knows her law and is resourceful and strategic in her every surprising move. They may not learn if she is the target or the perpetrator without getting the story directly from her. Even then, as she is a lawyer who knows how to spin, they have to act the judge and jury in their own court of opinion in evaluating her story. Meanwhile, as Carter assists them on this case, she finds that she has to be careful around her new rookie partner, Laskey. She doesn't yet know how careful she truly has to be.

Shaw is tasked with staying close to a 10-year-old girl identified by The Machine. Meanwhile, Carter's continues her mission to take down HR.

Root reappears and kidnaps Shaw. Finch helps an estate investigator who looking into the death of his step brother. A new vigilante group (Vigilance) makes it presence known. Carter's young partner has his loyalty to HR tested.

A hypnotherapist, who's really a con man, pumps his patients for personal information while they are hypnotized. One of his patients is an antique dealer who launders money for HR.

Finch receives 38 numbers at once from the Machine. He discovers they are connected to an unknown player who is inciting an all-out war between HR and the Russian mob.

Danger closes in when the epic battle to bring the criminal organization HR to justice reaches new heights. And when the Machine suddenly gives out Reese's number, the POI team faces their greatest threat yet.

The team seeks justice for Carter's murder, but Finch realizes that one person may go too far in the battle against HR. Meanwhile, NYPD officer Patrick Simmons' number comes up.

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.

Sameen, Harold, and Arthur make their escape. Root is captured and tortured. The others go to recover Arthur's back up hard drives but are caught in the crossfire when Vigilance arrives to claim them for themselves to expose Samaritan.

Reese, still angry and racked with guilt over Carter's death, is sent on a flight to Europe, following cryptic instructions that lead him to a POI and fight for survival while trapped on an 8hr flight.

Reese rejoins Finch and Shaw for a case involving a Olympic gymnast turned event planner.

Finch goes undercover in an emergency call center to protect a 911 operator, who's being forced to cooperate with the kidnapper of a young boy. Before long they find out they connected to a murder Fusco is investigating.

A flashback to the early days of Finch's operations reveals secrets and connections with far-reaching implications.

The Machine tasks Root to find a janitor who has a mysterious past. However, when her presence endangers him, the Machine sends his number to Finch as well.

The team gets involved in a case of international politics when a former government contractor stalks a U.N. diplomat. Meanwhile, an adversary tries to take advantage of Root.

Reese and Shaw go to a H.S. reunion to shadow a prosecutor who may have been involved in a killing 20 years ago. Finch and Fusco compete with the FBI to find out why a government employee was killed. And not far behind is Vigilance.

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.

Decima hunts down Reese and Shaw using Samaritan's feeds. Meanwhile, Greer sets a trap for Finch by targeting his former fiancée, Grace.

While Reese and Shaw search for Finch and a way to stop Decima, The Machine gives them 5 new numbers.

The team takes desperate action in its race to prevent 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.

Required to assume new identities created by Root, the team tries to adapt to their new lives, but a new number complicates things.

Harold reluctantly agrees to help John protect a young woman who is participating in a dangerous game, meanwhile Shaw continues her extra curricular activities.

Finch recruits Fusco to stick close to the latest POI, a professional "wingman", but learning how to approach women soon becomes the least of his worries. Meanwhile, Reese must find a way to play by the rules at his new day job as the Machine sends Finch and Root on a mysterious errand.

Reese's cover job as an NYPD detective becomes complicated when the young brother and sister he's protecting become targets of a gang investigation.

On Election Day Reese shoots a potential jumper and is forced to go into counseling. The new number is for a pollster who suspects the election for Governor of New York was rigged. It was - by Samaritan, and his life is now in danger.

John and others try to prevent a fake detective from getting himself killed, while Harold attends a conference in Hong Kong.

Shaw joins a team of international thieves in order to keep tabs on the latest POI, but an unexpected turn of events puts her in danger of being detected by Samaritan. Also, Finch and Root undertake a dangerous sabotage mission.

Reese volunteers as an NYPD police academy instructor in order to keep an eye on a talented young officer whose suspicious actions make him question her motives. Meanwhile, Martine, armed with information from Samaritan, hunts a member of the team.

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.

Samaritan demonstrates its true power by taking control of New York for 48 hours and erasing crime from the city in an attempt to lure The Machine out of hiding.

Samaritan launches a cyber-attack on the stock exchange, leaving the team with no choice but to embark on a possible suicide mission in a desperate attempt to stop a global economic catastrophe.

The hunt for Shaw takes Root and Reese to a small town in upstate New York where not everything is as idyllic as it seems; Fusco and a former person of interest team up.

Reese and Fusco get caught in the war between Elias and Dominic while Finch and Root follow a clue to Shaw's whereabouts.

Root and Finch work on bringing Northern Lights back online. They are successful and thus they start receiving numbers from the irrelevant list. However, the Machine is not as productive as before.

Shaw escapes her captors, but the team is unsure of her mental state when she begins to act paranoid and reckless.

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.

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.

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.

Reese and Finch become trapped in a hospital that becomes ground zero for a deadly viral outbreak. Also, Samaritan's newest recruit has second thoughts and Shaw continues to struggle with reality.

The mysterious criminal mastermind known as "The Voice" returns and traps Reese and Fusco in their own precinct with several armed gang members and the latest POI. Also, Root makes a shocking discovery.

Finch's number comes up when his cover identity is blown and sets off a deadly series of encounters with Samaritan's operatives.

Harold goes on a road trip with the Machine, while the rest of the team receive a new number; the president of the United States.

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 of the war with Samaritan.

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, leaving the team with no choice but to embark on a possible suicide mission in a desperate attempt to stop a global economic catastrophe.

Shaw escapes her captors, but the team is unsure of her mental state when she begins to act paranoid and reckless.

Sam Shaw and her associate Michael Cole receive the Relevant numbers from the Machine.

Shaw joins a team of international thieves in order to keep tabs on the latest POI, but an unexpected turn of events puts her in danger of being detected by Samaritan. Also, Finch and Root undertake a dangerous sabotage mission.

Reese rejoins Finch and Shaw for a case involving a Olympic gymnast turned event planner.

Shaw is tasked with staying close to a 10-year-old girl identified by The Machine. Meanwhile, Carter's continues her mission to take down HR.

Reese and Finch become trapped in a hospital that becomes ground zero for a deadly viral outbreak. Also, Samaritan's newest recruit has second thoughts and Shaw continues to struggle with reality.

Reese and Shaw go to a H.S. reunion to shadow a prosecutor who may have been involved in a killing 20 years ago. Finch and Fusco compete with the FBI to find out why a government employee was killed. And not far behind is Vigilance.

The team gets involved in a case of international politics when a former government contractor stalks a U.N. diplomat. Meanwhile, an adversary tries to take advantage of Root.

While Reese and Shaw search for Finch and a way to stop Decima, The Machine gives them 5 new numbers.