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.

Reese poses as a Secret Service agent to get close to the latest POI, a U.S. congressman who may hold the key to derailing Decima’s plans to bring a second Machine online.

As Decima uses Samaritan’s feeds to hunt Reese and Shaw, Greer exploits Finch’s greatest weakness in an attempt to lure him out of hiding: his love for his former fiancée, Grace Hendricks.

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.

Forced to take on new identities provided by Root, the team members try to adapt to their new lives. However, some find it hard to ignore The Machine's numbers, which puts them all at risk of being detected by Samaritan.

Control, who oversees the handling of relevant numbers for the government, begins to question the methods and intentions of the Samaritan program. Also, alarming news reports of a pair of vigilantes rampaging through the Northeast begin to surface.

Finch and Root race to save The Machine, which has been located by the rival AI, Samaritan. Also, Reese is caught in the middle of the final showdown between rival crime bosses Elias and Dominic.

As Reese and Shaw race to catch up with Finch, he infiltrates a maximum-security government facility in a desperate mission which could mean the end for not only Samaritan, but for himself and The Machine as well.

Finch, Reese, Fusco and Shaw embark on one last mission to prevent Samaritan from destroying The Machine and cementing its hold over mankind.