Don and his team are out to protect former radical Benjamin Polk from a determined sniper who wants him dead, and who is leading the FBI on a cat-and-mouse chase as he closes in on his prey.
Two FBI agents are killed during a bank robbery, Don's team is called to investigate. Meanwhile, Charlie and Amita begin to worry when Larry doesn't want to attend a conference in Geneva.
To find the person behind a deadly gambling ring that is running a high-stakes Russian roulette tournament, Don and his team are called in to investigate. Elsewhere, Don and Charlie become concerned over the financial health of Alan.
The team investigates several deaths that turn out to be copies of a soon-to-be-released movie, while Larry goes on his own personal adventure.
The team tries to track down the daughter of a geneticist who they believe was kidnapped by her mother. However, the case becomes complex when they have reason to believe the daughter was a clone. Meanwhile, Charlie and Amita discuss having children, and Liz reveals a secret.
The team investigates a decommissioned air base after a woman is found dead there, but their investigation is interrupted by paranormal happenings.
In order to track down a cyber crime lord, the team puts together an undercover sting, but their operation is stalled by a hacker who is trying to take over the Internet. However, his attempts to take over the Internet may lead to a dangerous online war that could result in murder.
While tracking down a criminal who is running a heroin ring inside of a prison, Agent Ian Edgerton becomes a murder suspect when an informant is killed.
Don and the team are lent a hand by convict John Buckley when robbers break-in to a diamond exchange and take hostages.
When the FBI takes down a gang responsible for a series of armored car robberies, the aftermath reveals something quite interesting, which is that some of the bills in the car were flagged as part of the infamous and unsolved D.B. Cooper hijacking
. The team calls in Agent Roger Bloom, who happened to have worked on the original investigation, for assistance.
The team looks into the theft of a batch of scratch-off lottery tickets, and they find out the culprit may be a former lottery winner.
The team is called when a shipment of high-caliber firearms goes missing, and one of the stolen weapons is used in random killings throughout the city. Meanwhile, Charlie and Amita disagree on a wedding date.
The team hunts down a serial killer who is targeting men who use prostitutes. Meanwhile, Colby and Nikki are involved in a car accident during the investigation.
The team search for jewels worth millions that were stolen during an awards show. Meanwhile, Don looks into an old case that has been haunting him and Larry returns.
The murder of two men takes the team to investigate a group of friends that had been sexually assaulted by a teacher at a younger age. Meanwhile, the perfect job opportunity pops up for Charlie and Amita, that may also put a wrinkle on their wedding plans.
After Charlie and Amita get married and begin preparations for their London adventure, they put a slight hold on their wedded bliss when they assist the team in helping Don track down the whereabouts of his gun after it goes missing.