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.

With Finch missing – kidnapped by his hacker nemesis, Root, Reese enlists Detectives Carter and Fusco to get his friend back, Meanwhile, The Machine never sleeps, disseminating a new number to Reese.

The Machine delivers the number of a cold case that leads Reese ever closer to catching up with Finch and his kidnapper, Root.

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.

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

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

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.

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

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 goes under cover to protect a youth who reminds him of himself; Carter goes on a dangerous mission for the FBI.

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.

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

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.

As Reese and Finch try to save a hotel maid's life, they encounter a litany of suspects; Detective Carter considers a significant offer from the FBI.

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 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.

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.

Finch infiltrates a tech corporation to gather intel on an executive whose number has come up; Carter questions Beecher's integrity.

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.

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

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.