The number comes up for an Internet entrepreneur in the business of eliminating people's privacy, but finds his own being rapidly stripped away. As his life spirals out of control, Reese tries to protect him while Finch calls on Shaw, Carter and Fusco for help finding whoever is after him.

After being freed from her confinement to the psych ward, Root needs Shaw's help with a directive from the machine; Finch and Reese look into a mild-mannered investigator.

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, HR.

Multiple enemies converge on the POI team as they protect a dying man whose number has come up. They struggle to keep their enemies at bay but without Reese, who has left them and their mission behind following the tragic war with HR, being down one man could have catastrophic repercussions for the team.

The Machine assigns Root to seek out a janitor with a mysterious past, but when her very presence puts his life in danger, Finch also receives his number.

Reese and Shaw pose as alumni at a high school reunion in order to keep eyes on the latest POI. Meanwhile, Finch and Fusco travel to Washington, D.C., to investigate the motivations behind Vigilance’s latest attack.

When an unknown entity prevents The Machine from seeing the full picture of an impending catastrophic event, it sends the team five separate numbers to help them piece together the bigger picture. Meanwhile, Root’s team of hackers arrives in New York.

The team takes desperate action in its race to prevent the malevolent AI program 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.