The team is fractured after Dr. Rosen is incarcerated in a psychiatric facility for revealing the existence of Alphas to the world. An incident inside Building 7 leads to a hostage crisis of super-powered proportions.
As the newly reunited team threatens to unravel, a man with super speed begins abducting doctors who he hopes can help him with his degenerative condition. Meanwhile, Danielle is forced to reconsider her relationship with Cameron.
When Bill and Hicks discover a fight club for Alphas, Bill lets a young woman train him as contender in order to find a killer. Meanwhile, Gary helps Dr. Rosen trace Stanton Parish's long history.
Bill, Gary, and Hicks have a series of strange encounters while searching for Rachel and a missing patient inside a hospital. Meanwhile, Dr. Rosen asks Nina for help in subtly interrogating a Senator for information on Parish.
The team travels to a remote commune of Alphas to get help from Skylar, an tech wiz who is hiding out from the law. But some of the locals hold a personal grudge against Rosen, while others plot to acquire the experimental new technology the team has brought.
After a gifted high school boy creates a hive mind to make his entire class do his bidding, Stanton Parish approaches Rosen to work together and defuse the situation.
Kat goes undercover to investigate a street drug that makes users invulnerable, which is being peddled by her old boyfriend. Hicks' son visits, and Dr. Rosen wrestles with what to do about the mole.
Rosen's actions prompt Hicks to join up with Stanton Parish's team, where an interrogator rips open his mind to test his loyalties. Meanwhile, the team tracks a stolen device capable of causing a massive power disruption.
While the team cares for an Alpha baby, Gary becomes suspicious of the child's parents who show up to claim him. Rachel and John accelerate their relationship, and Lee struggles with his recent loss.
As the team rounds up Parish's known accomplices, Cameron and Kat find a man gifted in memory recall sequestered in a remote area -- only to wind up hunted by his guardian. Meanwhile, Senator Burton's arrival threatens to expose Nina's actions and derail Rosen's plans.
As Parish's attacks escalate, Dr. Rosen goes behind the government's back to catch and interrogate one of his men. Meanwhile, Gary discovers a way to track down Skylar and her daughter.
Critically-wounded and increasingly delusional, Dr. Rosen scours the city to find Stanton Parish and avenge his daughter, while the team races to stop the madman from enacting his catastrophic plan.