The FBI are getting closer to the head of HR. Mr. Reese tries to prevent a young journalist that likes taking risks from being killed. To avoid getting media attention, Mr. Reese starts dating her. Fusco is playing double.
Reese and Finch's latest number is twenty-six year old Abby Monroe, who they expect will be the target based on basic information they have about her. She is a past honor student having received a degree in engineering. She worked the past year for Homes for Our Returning Heroes, a military charity that supports returning veterans financially, that job Reese and Finch surmise in honor of her brother who was killed in Afghanistan. She, however, left that job to work instead for the city planning department. Their belief that she will be the target does not diminish ...
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?