Season 1 of Nikita premiered on September 9, 2010.

When she was a deeply troubled teenager, Nikita was rescued from death row by a secret U.S. agency known only as Division, who faked her execution and told her she was being given a second chance to start a new life and serve her country. What they didn't tell her was that she was being trained as a spy and assassin. Ultimately, Nikita was betrayed and her dreams shattered 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 bosses that she will stop at nothing to expose and destroy their covert operation. For the time being, however, Division continues to recruit and train other young people, erasing all evidence of their former lives and turning them into cold and efficient killers. One of these new recruits, Alex, is just beginning to understand what lies ahead for her and why the legendary Nikita made the desperate decision to run.

Season 2 of Nikita premiered on September 23, 2011.

Nikita waged a war against Division. In the process, her relationship with Alex, the girl she trained to infiltrate the secret agency was destroyed, and her relationship with Michael, the man who trained her, was restored. Now, Nikita and Michael are on the run with a hard drive containing the government's darkest secrets and conspiracies. Together, they are going to right the wrongs that Division has committed over the years, one mission at a time. But leading the hunt for them this time is Alex...and she knows all of Nikita's tricks.

Season 3 of Nikita premiered on October 19, 2012.

Nikita and Michael set out to correct the wrongs of Division... only to discover that Alex, Nikita's protégé, has joined Division in order to avenge her father's death. When Nikita helps her achieve her vendetta, the trio is once again united, and a new, powerful team of heroes is formed. These include punk rock hacker Seymour Birkhoff, brilliant CIA analyst Ryan Fletcher, and ex-Navy SEAL Sean Pierce. Nikita began her journey by searching for a home she never had, only to find a home she never expected: Division itself.

Season 4 of Nikita premiered on November 21, 2013.

Nikita took over Division, and working alongside her fiancé Michael, her protégé Alex and a team of covert operatives, she vowed to capture all rogue Division agents and shut the place down. But she got more than she bargained for as Division's corrupting influence began to tear her family apart. Even worse, Nikita's nemesis, Amanda, set out to destroy her by teaming with the shadowy global organization known as The Group. Together, they pulled off a shocking assassination that promises to disrupt the balance of world power forever. And with the blame for the murder falling on Nikita, she is forced to come full circle and go on the run as a hunted rogue as she attempts to clear her name as well as spare the people she loves.