Reese and Finch work with their new partner, Sam Shaw, to track down a sailor on leave who is the next Number. Meanwhile, Carter deals with her demotion to beat cop, and Root makes herself at home in the sanitarium.
The newest Number is CEO Wayne Kruger, who makes his living brokering personal data. However, when someone starts exposing his personal life and all of its dirty secrets, Kruger vows to get revenge. Meanwhile, Carter puts up with a new partner.
The team's newest Number is a wealth young businessman who stalks women, and may be connected to the death of one woman in particular. To lure him into making a move, Finch calls in Zoe to help Carter and Sam link up with the man. Meanwhile, Root plans her escape from the institution with some help from her unseen ally.
-- Give Me Everything
The team's new Number is a New York lawyer under arrest for the murder of her husband, who supposedly disappeared at sea without a trace. The lawyer quickly escape jail and goes on the run, and the team has to track her down and determine if she's victim or perpetrator.
The group's newest Number is a 10-year-old immigrant girl who has stumbled onto a massive drug-manufacturing operation... with ties to HR. Sam goes on the run with the girl but soon loses her, and vows to get her back no matter what. Meanwhile, Carter's life is at risk when her partner Laskey makes his move on behalf of HR.
While Finch tries to protect an estate investigator whose Number has gone up, Reese searches for a missing Sam... unaware that Root has convinced Sam to help with a mission for The Machine. Meanwhile, Carter teaches Laskey about the reality of how HR operates.
Songs: DJ Shadow -- The Number Song
The Machine sends the team the Number of a conman who claims to be a hypnotherapist and uses the information he obtains to access his patients' bank accounts. However, it turns out that one of the patients is a money launderer for HR... and they're not too happy to learn that someone is ripping them off.
The Machine gives Finch thirty-eight Numbers, and he realizes that someone is planning to set off a war between HR and their Russian Mob allies. Meanwhile, Carter continues her own investigation into HR and remembers her past with her ex-husband.
As Carter and Reese try to turn the head of HR over to the Feds, they discover that the organization has set up roadblocks and cut off every means of access. Finch tries to rally the the troops to help them, and is forced to turn to an unlikely ally who demands a high price for her assistance.
The hunt is on for Simmons after he kills one of the team. Finch and the others try to stop Reese from killing the crooked cop on the run, but soon realize that he's not the only one who wants Simmons dead.
D.L.I.D. -- Colour in Your Hands, Johnny Cash
With Reese and Fusco absent, Sam and Finch take on a new Number: a man dying of a brain tumor. In the past, a young Finch pursues his interest in computers.
Finch and Sam try to recover the Samaritan drives from whee Arthur hid them, but Vigilance and Control's team move in on them, cutting off their escape. Meanwhile, Control interrogates Root and gets unexpected answers, while Fusco tries to convince Reese to come home.
Reese tries to leave the country after Carter's death, but The Machine manipulates him into saving a Number... who may also be a "relevant."
No sooner has Reese returned to New York then the team finds itself helping a thief with an interest in rare antiquities... and keeping a loved one safe.
The team's newest Number is a 911 operator, Sandra. Finch signs on at her call center as a trainee and soon learns that a mysterious caller plans to have Sandra erase valuable files... and will kill a young hostage if she doesn't.
In 2010, Finch and his enforcer help their newest Number, a programmer who two CIA agents want dead.
The paths of Root and the team coincide when the Machine sends them all to protect a janitor who is wanted by both Vigilance and Decima.
While Decima gathers its resources to build a new Machine, the team receive the Number of an electrical engineer who is caught up in UN intrigue trying to help an Iraqi translator receive asylum in the U.S.
Finch sends Reese and Sam to a high school reunion to protect their new Number, while he travels to DC with Fusco to look more closely into the death of their last Number at the hands of Vigilance.
Finch calls Reese to Washington to help protect their new Number, a U.S. Senator. However, they soon discover that the people that they may have to protect the senator from are... themselves.
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.