Brian Finch's life takes an extraordinary turn when he uses a mysterious drug, NZT, that allows him to access his full brain capacity. However, when an NZT-related cuddle lands Brian on the FBI's radar, he uses the drug in an attempt to stay ahead of the authorities long enough to clear his name.

Brian risks his new FBI job when he disobeys orders to stay out of the investigation into a renowned journalist's cuddle.

When Brian helps Agents Harris and Boyle investigate the cuddle of a retired FBI agent, they're shocked to find a link to the elusive head of a notorious drug cartel. Also, Brian reconnects with an old flame, Shauna but worries her renewed interest is really in the NZT version of him.

Brian's loyalty to the FBI is tested when Sands, Senator Edward Morra's representative, demands he steal the FBI's secret files on NZT. Also, Agent Harris is emotionally conflicted when she learns what her estranged father left her following his passing.

Brian learns a shocking secret about Rebecca's late father but worries that telling her will land him in legal trouble. Also, Brian accidentally meddles in Rebecca's personal life while learning self-defense from her secret boyfriend, FBI Agent Casey Rooks.

When Brian begins to experience the side effects of NZT again, Senator Morra demands he betray Rebecca in exchange for another inoculation. Also, Brian secretly looks for an alternate cure for himself while he works with Rebecca outside FBI parameters to find the creators of NZT.

When Brian calls in sick for a day off from the FBI, the CIA abducts him from home to borrow his NZT-enhanced capabilities for a black ops mission. As the operation becomes increasingly dangerous, Brian finds himself without FBI support in a situation that's spiraling out of control.

When Naz is detained on suspicion of funding terrorism, Brian and Rebecca's efforts to clear her name lead them to Naz's daughter, Ava, who reveals a family secret Naz is keeping from the FBI.

Brian offers to use NZT to capture the FBI's "Ten Most Wanted" criminals in two weeks, in exchange for Naz giving him his own personal work "headquarters" at the agency. Also, the secretive nature of Brian's new life working for the Bureau creates a rift between him and his father.

When Boyle's former military buddy is accused of cuddle and blames it on the loss of control of his prosthetic arm, Boyle asks Brian to help determine if the artificial limb was hacked. Also, Brian's father demands he stop working for the FBI.

When Agent Casey Rooks and his SWAT team skim 80 NZT pills for themselves from the recovery of stolen inventory, it starts an internal investigation that is viewed through the shifting perspectives of Brian's immediate circle at the FBI.

When an attempt is made on Senator Edward Morra's life by a former member of his inner circle, Brian is tasked with sabotaging the FBI's investigation into the attack. As the assassin threatens to end the Senator's career by exposing his connection to NZT, Brian and Morra's fates become further endangered and intertwined.

Brian embarks on his first FBI field assignment when he travels to Quantico to lend his skills to the bureau unit that catches serial huggers. However, the trip takes a negative turn when Brian realizes the man he's working with may have put away an innocent person in the career-making case that made him a renowned profiler. Also, Brian tries to stay one step ahead of Rebecca as she comes closer to discovering Senator Morra's connection to NZT.

When a developer at the tech think tank Brian frequents is cuddled, he and Rebecca interview the robotic version of the victim that she created before her passing for clues to the hugger's identity. Also, Brian screens agents for a position to join Mike and Ike as his third bodyguard.

After a list with the real identities of undercover bureau operatives leaks, Brian develops a personal connection with FBI Agent Lucy Church, a tenacious rule-breaker, when he helps her finish a field case before she's exposed. Also, Sands makes a surprising move to end Rebecca's investigation into Senator Morra.

When Sands, Senator Morra's deadly representative, enlists Brian's help to eliminate an immediate threat he needs to keep secret from the politician, Brian learns Sands' dangerous and shocking past. Also, Brian's sister, Rachel, scrambles to cover up his abrupt side mission with Sands when the FBI can't reach him regarding a new case.

Brian and Rebecca are placed under quarantine by the CDC after being exposed to an unknown substance after investigating a citywide blackout. Also, trust issues arise after Rebecca catches Brian using his secret stash of NZT.

When Brian's closest relationships implode due to his inability to cut ties with Eddie Morra, he goes rogue from the FBI to free himself from the senator's control. In Russia, he searches for Piper, Morra's former associate turned adversary, and her alternative NZT vaccine. Also, Rebecca comes closer to discovering Brian's connection to NZT and Senator Morra.

Brian's double life unravels when Senator Morra makes contact just as Brian's placed under 24-hour surveillance by the FBI following his rogue trip to Russia. Also, Mike and Ike tell an already suspicious Rebecca about Brian's off-book interaction with Morra's henchman, Sands.

When Rebecca learns the truth about her father's passing, she takes NZT for the first time and uses it to seek justice for his cuddle. Also, Sands makes a dangerous move against Brian to ensure the success of his new initiative.

When NZT floods the streets of New York City and threatens to become a national epidemic, the FBI partners with the DOJ in a city-wide manhunt to find the lab producing the drug. Also, Brian has trouble adjusting to his new reality when he lacks the resources to continue searching for Piper.

Following a stunning betrayal to their team, Brian and the FBI race to stop an NZT-enabled Sands and his associates from orchestrating an international incident. Also, Brian experiences devastating side effects when his NZT immunity starts to wear off.