Division sends Thom to eliminate Anna, a woman who was having a secret affair with a U.S. Senator. Division agrees to cover up any trace of the affair as long as the Senator agrees to help pass a bill that will continue to fund the agency. Nikita, with Alex's help, attempts to reach out to Anna's parents, but the conversation doesn't go as she expected.

Ryan intercepts information about a dangerous new weapon coming into the U.S. and asks Nikita to help him prevent its delivery. Nikita learns that the man bringing the weapon into the country is Voss, a man Division forced her to have a relationship with while working undercover. She reluctantly resumes her alter ego to prevent the weapon from being delivered. Meanwhile, Michael interferes with Alex's relationship with Nathan.

Michael confronts Nikita in her lair and reveals that he knows Alex is the mole. He tells Nikita that she has 24 hours to find Kasim, the man who killed Michael’s family, or he will tell Percy about Alex.

While investigating an old corrupt Division program, P9, that seems to have resurfaced, Nikita and Michael run into Owen. He tells them he is searching for Dr. Joseph Mars, who is not only the mastermind behind P9, but also invented the Regimen and could help Owen wean himself off the dangerous drug. Michael is hesitant to trust Owen again but Nikita decides the three should join forces. Percy demands to see Alex.

Nikita is stunned when she hears that her old Division partner Kelly escaped from a Turkish prison. Nikita thought Kelly died years ago and always felt responsible because it happened on the mission where Nikita escaped from Division. Knowing Amanda will go after Kelly, Nikita tells Michael they have to go to Turkey to help her. Amanda sends Alex and Roan to Europe to stop the former partners from reuniting.

With Michael out of town, Nikita turns to Owen to help her track down and steal another black box from a Guardian. Unfortunately, she discovers that Owen is working for an unlikely employer that could jeopardize Nikita's whole operation. Amanda realizes Alex received privileged information about Semak and that information could only have come from Percy. Furious that Percy undermined her, Amanda strips him of all his amenities. Back home in Russia, Alex finally makes her move on Semak.

Alex’s mission to take down Gogol comes to a head as she infiltrates her childhood home and faces ghosts from her past. On a completely separate mission, Nikita also ends up at the mansion to steal Semak’s black box. Nikita and Alex run into each other and decide to join forces, but they run into a major roadblock. Meanwhile, Michael and Owen work together to figure out Percy’s secret plan with the Guardians.

Sean attacks Nikita and Michael in an effort to protect his mother. Meanwhile, Percy gets the upper hand on Amanda and threatens to level Division unless she releases him.

Percy has his Guardians hold the members of Oversight hostage until Amanda agrees to his demands. If she doesn't, the Guardians will shoot all the members of Oversight and release a deadly gas inside Division that will instantly kill everyone, including Amanda. Nikita is torn between letting the enemy fall and saving the innocent lives inside Division. Meanwhile, Sean is frantic to save his mother from Percy's clutches and turns to Nikita, Michael and Alex for help.

Nikita and Michael try to help Carla remember her past, which holds the key to taking down Division. Carla recounts the night Nikita was arrested and Nikita is stunned at what she learns. Meanwhile, Alex shows up at a Zetrov press conference where Semak is speaking and announces that she’s Alexandra Udinov.. Alex demands a trade – her mother for the empire.

Division is in an uproar when their agents are being assassinated one by one. Amanda realizes Percy is behind the murders and is trying to undermine her authority with the other Division agents. She reluctantly calls Nikita with an offer that is hard to resist – stop Percy and she’ll give Nikita Ryan.

Michael is furious when he discovers a secret that Cassandra kept from him, so he and Nikita fly to Moscow to confront her. Meanwhile, Alex makes a last ditch effort to find her mother by sending out a coded message through a televised interview.

Amanda and Ari set up a board meeting with Zetrov and prepare to take over the company. After a heated face-to-face confrontation between Nikita and Amanda, Nikita recalls what Amanda was like when she was first brought to Division. Meanwhile, Alex surprises Ari by showing up at the board meeting with an old and powerful friend.

Amanda sends a rogue Division agent, Anne to spring Owen from a Russian prison, but Owen manages to escape her clutches and sends a message to Nikita that he’s free. When Nikita tracks him down, Owen is shocked to learn that Nikita is with Division now but returns to base with her. Michael and Ryan aren’t sure they can trust Owen but Nikita stands by her friend.

Nikita and Michael capture Cyrus, an arms dealer, who is purchasing a weapon-jamming device for Ari. Nikita convinces Ryan to let them use Cyrus as bait to capture Amanda but Cyrus manages to escape the trap. However, when Amanda double crosses Cyrus, his only hope for survival is Nikita. Meanwhile, Birkhoff is hot on the trail of Amanda’s mole and Alex starts to unravel.

After Birkhoff gets a tip from Shadowbot that Ari is in NY, Nikita and Owen swoop in to pick him up before the FBI does. However, Ari reveals he planned everything for a chance to talk to Nikita. He tells her that Amanda has gone too far and is working with a terrorist who plans an attack on American soil. Ari wants fifty million dollars for the information that could lead to the terrorist’s capture. Nikita and Michael are stunned when Ryan considers paying the bribe. Meanwhile, Sean is jealous of Alex and Owen’s relationship.

In order to gain control of the black box, Amanda makes plans to kidnap Ari's son Stefan (Dylan Minnette) to use him as leverage. Still in Division’s protective custody, Ari begs Nikita for help. However, Stefan’s bodyguard Krieg (Andrew Divoff) manages to capture both Nikita and Amanda and the two must work together to escape. Owen is furious with Michael after Michael assigns Alex to be Nikita’s back-up instead of him.

Amanda holds Alex hostage and tells Nikita she will release Alex in exchange for Ari. Michael assigns Nikita and Sean to handle the exchange of prisoners, but Ryan adds Owen to the team at the last minute, which makes Michael suspicious. While in captivity, Alex befriends a fellow prisoner named Larissa and vows to break them both out of the jail, which ultimately conflicts with Nikita’s plan, forcing Alex to choose between Nikita and her promise to Larissa.