When she was a deeply troubled teenager, Nikita was rescued from death row by a secret U.S. agency known only as Division, who trained her as a spy and assassin. Nikita was eventually betrayed by the only people she thought she could trust. Now, after three years in hiding, Nikita is seeking retribution and making it clear to her former boss, Percy and her former friends Michael and Birkhoff that she will stop at nothing to expose and destroy their covert operation. Division continues to recruit and train other young people, among them Jaden and Thom, erasing all evidence of their former lives and turning them into cold and efficient killers. One of these new recruits, Alex is a beautiful girl with a violent past and a story not so different from Nikita's. The recruits all spend part of their training with Amanda, a master manipulator who can turn any ugly duckling into a swan and any bleeding heart into a killer.

Percy and Michael take their latest assignment, a Slavic leader wanted for war crimes, into protective custody. Nikita learns of their hideout and attempts to thwart their plan, but a mysterious group of mercenaries in search of nuclear material beats her to the task. Alex is activated earlier than expected for a special assignment that throws her into the crossfire of bullets. A flashback reveals a pivotal moment in Nikita's life.

Nikita rescues Jill, a journalist who is trying to expose a conspiracy involving Division and a major plane crash. Michael and Percy suspect Birkhoff of being Nikita’s inside mole and send Amanda in to interrogate him. Meanwhile, Michael enlists the help of the recruits, Alex, Jaden and Thom, to help them locate their latest target.

Nikita delves into her past when she posed as a nanny for an influential government official and decides to right the wrong of his death. During the mission, Michael comes to Nikita’s rescue and begins to doubt Percy’s motives. Back at Division, while undergoing basic training, Alex suffers from a panic attack which prompts Amanda to break her of claustrophobia.

Divison’s secrets are at risk of being revealed to the world when Owen, a Division operative, escapes from a bank robbery and becomes a fugitive. Percy decides to search for Owen himself, which makes Michael suspicious of his motives. Meanwhile, Alex sneaks into Percy’s office to warn Nikita, but she is busted by Thom. In the end, Nikita and Owen go head-to-head until Percy joins them for a tense standoff.