Special Agent Donnelly has Reese, along with three other men, in seventy-two hour custody on Riker's Island. With Finch's help, Carter is in unofficial charge of helping Reese get out of custody without disclosing to Donnelly that Reese is indeed the "man in the suit" that Donnelly considers the most dangerous man on the loose. Although Carter has a plan to do so, she may find that tenacious Donnelly may not let Reese and the other three go so easily if he has not yet found out which one is the man in the suit. Meanwhile, Finch, largely with Fusco's help, is handling ...
Reese finds being saved by Stanton means having a bomb strapped to his chest while he and Snow infiltrate a DoD lab. A flashback shows how she survived the missile attack and Greer makes his first appearance.
A tech billionaire's erratic behavior threatens to destroy his business empire, which may mean one of his subordinates wants to put an end to him, if one of the many competitors he's crushed doesn't do it first.
Finch and Reese go undercover in a hotel to protect a cleaning woman who is the apparent target of Serbian killers. Meanwhile, Carter begins the process of joining the FBI and someone from their past unexpectedly returns.
The Machine suddenly provides six numbers, one of whom has a place on remote Owen Island. Because of a tropical storm Finch and Reese are trapped there with eight others, and one is them is methodically killing the others, one by one.
After saving Leon Tao yet again, Reese goes to Atlantic City to watch over a retiree who's losing a fortune in the casino. HR smears Szymanski so that he can't testify at a Russian mob trial and Carter risks her life trying to clear him.
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.
A respected doctor is poisoned with Polonium and has just 24 hours to help Reese find his killer. Carter, grieving over the death of Cal Beecher, helps Fusco when HR turns Internal Affairs against him.
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?
Nobody knows where the Machine has now relocated itself, but it is still in contact with both Finch and, by association, Reese and their new partner Shaw, as well as Root. Still institutionalized, Root may have a short term problem in dealing with her psychiatrist, whom she sees as being stupid, and from whom she has not been provided access to any electronic devices including telephones. Carter, now demoted to patrol following her HR-initiated wrongful shooting incident, has her own new primary agenda. She has also not told Finch or Reese of her association with a ...
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 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 ...
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.
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.
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.