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.
When a virus causes the machine to malfunction, numbers are issued irregularly; the team searches for an extremely elusive tech millionaire.
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.
Finch infiltrates a tech corporation to gather intel on an executive whose number has come up; Carter questions Beecher's integrity.
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.
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 latest POI - a deadly government operative who tackles terrorist threats - proves difficult for Reese and Finch to protect.
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.
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.
Reese is captured by a former acquaintance planning a massive and potentially deadly act of cyber-warfare.
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.
Finch goes under cover to protect a youth who reminds him of himself; Carter goes on a dangerous mission for the FBI.
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.
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 faces a challenge when the numbers of both a man and his wife come up in the machine.
A resourceful third party raises the stakes as Finch and Reese try to protect their latest person of interest, a brilliant surgeon.
The Machine’s latest number sends Reese to the suburbs.
Reese must surreptitiously protect an investigative reporter without becoming a part of her story.
Reese and Finch wonder if they should intervene when they learn that a mob enforcer's life is in danger; Finch turns to an unexpected source for help.
Reese protects the spoiled daughter of a Brazilian diplomat.
As Reese investigates a cold case, he gets closer to Finch and his kidnapper, Root.
Reese asks Detectives Carter and Fusco for help finding Finch, who was kidnapped by his nemesis.
