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 despondent over Carter's death, boards a flight to Europe and gets a cryptic message on a cellphone about a passenger who is supposed to be just a low level programmer, but is the target of a drug cartel and the Mossad.
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 involved in.
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.
News of Northern Lights has hit the media, meaning that the team's work has become more difficult if only because of the public eye on what is happening. While Shaw heads off with Root on her next assignment, Reese heads to Washington DC to reunite with Finch for their next number, that belonging to Illinois Congressman Roger McCourt. Finch's initial guess is that they are heading into uncharted territory as he believes that McCourt is not only the target or the perpetrator of an individual crime, but also that his number is related to terrorism or national security ...
Decima has completed its beta test of Samaritan and has now shut it down temporarily as Greer has to get the politicos, namely Garrison, to buy into the need to purchase it in the name of national security. Greer needs this to happen as they require the government feeds for Samaritan to operate properly. With Finch now being held by Greer and Decima, Reese believes that their first priority should be to retrieve him. However, Root, in her continuing contact with the Machine, convinces Reese and Shaw that the Machine is telling her that Finch, for the time being, is ...
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.
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.
The next numbers the Machine provides are for fourteen-year-old Malcolm Booker, and his eight-year-old sister, Tracie Booker, who are in foster care as their mother is incarcerated on a conviction for illegal firearms possession. Reese, who is tasked with finding them, quickly learns that they are the intended targets, as they stole $500,000 in drug money from the Brotherhood, a gang led by the unknown Dominic. Reese knows of the Brotherhood because he helped put in jail one of the gang's higher ups, Link, who is now out. The DEA is interested in the case, their head ...
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.
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.