While the bugs continue to spread through Washington, Laurel and Gareth find themselves unexpectedly thrown back together. Meanwhile, Luke tries to defeat Red's scheming and refund the CDC.
The mystery surrounding Lee Harvey Oswald deepens as George suggests that the ex-Marine meet with his "friends". Meanwhile, Bill and Marina grow closer, and Sadie confesses her secret shame to Jake.
Jake remains in 1960 to determine if he can change history by saving his friend Harry's family from their vicious father. However, he soon experiences what Al warned him about: that time doesn't like to be changed.moreless
Avery's ex-husband returns from a trip to Tokyo. When he presents his Passport to US Customs, he is shocked to learn he is dead. A Black Hat Hacker has somehow hacked into the US Government's Official Death Record and created a false death certificate for him. Avery's team quickly arrest the hacker. As the team congratulates themselves on another solved case, it is discovered that another hacker, who is apparently a member of a collective who specialize in killing people online, aka "Cyber Murder", has declared three witnesses against a powerful Drug Lord dead online. Two of the witnesses are immediately murdered. Avery is forced to seek assistance from the Black Hat who targeted her ex-husband in order to find the third witness before the Drug Lord does.moreless
The team investigates the murder of an immigrant petty officer that was staged as a suicide. Also, the agents secretly create an online dating profile for Pride.
The Machine sends the team two new Numbers: Elias and Dominic. Meanwhile, Finch and Root get a clue to Sam's whereabouts, and Control tries to learn the truth about Samaritan.
The race is on to rescue Beth, who is fighting for her life against Ray, who has sinister plans for her.
Reese and Finch protect a street-savvy grifter who makes the mistake of stealing laundered money from Dominic. Meanwhile, Root infiltrates a software app company on the Machine's behalf.
The team investigates the harassment of a former skinhead that may be caused by one of his former followers.
The team's new number is a professional wingman, and Fusco has to go undercover as a needy client while Reese deals with a demanding police captain. Meanwhile, Root takes Finch on a scavenger hunt for the Machine.moreless
Now that they have Samaritan up, Decima begins the hunt for Reese, Sam, and Finch... and plans to use Grace Hendricks to lure Finch out of hiding.
Monroe makes a jolting attack on the Patriots while Gene and Miles look for potential allies in Willoughby. Neville and Jason find themselves in deep water when Doyle finds out about the poison. Aaron and Priscilla press onward.moreless
Det. Kennex and Dorian track down the murderer of a "chrome" who, in his quest for perfection, is tapping into the DNA of his victims via a pinprick on the back of their necks.moreless
The Machine gives Finch Reese's Number as HR puts out a contract on the "Man in the Suit."
Texas Ranger John Fry comes to town who may be the only man capable of taking down The Patriots.
While Reese tries to protect the newest Number, an Internet entrepreneur with a stalker, Finch sends Carter, Fusco, and Sam to find the stalker. Meanwhile, Carter learns to live with her new partner now that she's been demoted to street cop.moreless
When the rebels discover a way into the tower, a deadly battle between Miles and Monroe occurs and the Nevilles are excluded.
Reese and Finch attempt to protect Mira, a hotel maid with a long list of enemies. Meanwhile, Carter gets a job offer due to her help in the "man in the suit" case.moreless
Rizzo blindsides Jack and grills him about Mia. Dixon learns the girl he saved from drowning was poisoned. Savino and his crew are stuck overnight in the desert.
In the mid-season finale, Miles and Monroe finally come face-to-face and Charlie encounters someone unexpected.
Reese and Finch set out to protect a surgeon who has come up as their newest Person of Interest. However, when they discover that someone from Reese's past is involved, they turn to a former Number for help.moreless
Lockhart Gardner must help to cover up Mr. Bishop's illegal business. Meanwhile, Eli struggles to deal with a blog that posted a story about Peter.
Steve goes to Cat for help finding his mother. When an art heist turns deadly, Five-0 turns to August March.
The detectives investigate the murder of two psychiatrists who were also husband and wife. A medical examiner attending a seminar offers to help Jane and Maura. A pregnant stranger may have something in common with the Rizzoli family.moreless
Finch gives Reese his birthday off so that his partner doesn't have to face a Number reminiscent of a case from Reese's past.
The team investigates a case involving a bizarre mutation that Peter solved in his original timeline four years ago.
McGarrett tracks down August March, a former diamond smuggler, to help clear his sister when she's arrested for smuggling conflict diamonds.
Reese and Finch help a schoolteacher targeted by the mob after he witnesses a hit.