Michael is captured and interrogated by terrorists, then loses his memory and does not know who he is.

While on a mission to tag a stockpile of Stinger missiles, the Section van is breached, and Birkoff is forced to defend himself for the very first time. Now, his fear of being killed on future missions is interfering with his ability to protect Section operatives, unless Nikita can help him overcome this fear, Birkoff is in danger of being cancelled.

Section believes that terrorists are after the nuclear power source of a downed satellite. They later discover the terrorists are actually after it because it is a military satellite and it will give them access to the Pentagon if they are able to salvage it and crack the codes. Nikita grows closer to Jurgen and Section uses it to their advantage.

The situation is dire as The Collective, still led by Graff and Haled, is cleaning Section's clock. But, just in time, Michael asks Nikita to help him return to Section, where his re-emergence is viewed with suspicion by both Mr. Jones and Operations. While new missions continue against The Collective with Michael's return, Nikita admits that she lied to him in "Four Light Years Further," and that she does indeed love him. Operations discovers that The Collective has infiltrated Section's mainframe to try to locate and kidnap Michael's son Adam, in attempt to re-assert control over him. Can Operations foil The Collective's plans?

When an international arms smuggler steals a canister of deadly nerve gas, Nikita and Michael pose as a married mercenary couple in order to infiltrate his compound. However, when the gas is discovered wired to a bomb in a crowded train station, Nikita must put her life on the line to defuse it.

While working undercover near a Central European Consulate, Nikita is confronted by a known serial rapist. Nikita easily subdues the man, leaving him battered and bruised. O'Brien, the police detective on the case, has been pursuing the man for years, and realizes that the rapist's victim was no ordinary woman. With the help of a witness he manages to break through Nikita's cover story and track her down. O'Brien now knows the truth about Nikita, he will have to be cancelled, unless Nikita can turn the situation around to her advantage.

Operations believes Nikita is a threat to Section, and wants to kill her during a mission. She survives his plot, and when she returns to Section, she looks into the disappearance of Michael, and finds what she didn't expect.

Nikita and Michael are sent on a mission to take out someone in a Balkan nation, but Nikita must force Michael into protecting two displaced children, however that protection prevents Nikita from hitting their target, and they must risk their lives in order to get him down.

When the founder of Section One comes back to destroy her own creation, Nikita must make a choice between the life of Michael or the existence of Section.

One of the members of a criminal organization that steals classified information to sell to the highest bidder is Operations' long-lost son, Steven. Section One's mission is to eradicate this group along with a dangerous terrorist that plans to buy a smart missile chip from them, but Operations asks Nikita to keep Steven alive at all costs. Nikita agrees, only if Operations will let her finally leave the Section for good. He agrees, but Nikita threatens to kill Steven if Operations doesn't keep his word. Unfortunately for Nikita, she is unaware of Michael's true role in the mission.

Nikita is promoted to team leader early and is sent on a much more dangerous than expected mission with a disobedient operative.

Nikita finds clues about why she was recruited into Section. Is it possible her father was an operative, codenamed Flavius, and that she has a sibling with the initial "M" who is somewhere in the covert world she lives in? Quinn redesigns Birkoff's Artificial Intelligence program to build a holographic replica of Madeline, complete with Madeline's memories and psychological profile. Although Operations is greatly pleased to have Madeline at his side once more, it soon becomes clear that despite it's complex programming, it is just not capable of being Madeline because it doesn't have her instincts.

When Nikita fails to assassinate Grenet, a Red Cell agent, and is unknowingly injured, Michael goes to her apartment to have dinner. It ends in disaster, when his water is poisoned and Nikita hands him over to Red Cell in exchange for his cornia files. She deletes herself from Section's databases and escapes to where they can't find her.

When Nikita is sent to investigate a bartender at a posh club who may be a terrorist contact, he responds to her questioning by leaping from the 65th floor window to his death. A search of his apartment turns up a strange helmet-like device, which Section later discovers is used for brainwashing. Unfortunately, Nikita has used the device several times in an effort to discover what it is, and now it is in control of her mind. When Nikita and other operatives are assigned to protect the Premier of China from other similarly brainwashed individuals, Section has no idea that the greatest threat to the Premier is Nikita herself.

The CIA believes that a rogue element of their agency is responsible for a recent massacre of heroin dealers, performed in order to steal money and drugs as part of an embezzlement scheme. Section One is brought in to clean the house quietly, but Nikita's continued involvement with architect Gray Wellman is tampering her ability to be a reliable operative. As Section One's operation reaches a fever pitch, Nikita is unable to balance both sides of her life, and is forced to make a choice between the organization that controls her life and the one man that she's ever loved.

David Fanning is one of the world's most dangerous hit men, but Section One is powerless to stop him. Fanning possesses ""The Book,"" a collection of top-secret information damaging to Western governments, and if the Section makes any attempt on Fanning's life, the Book will be released automatically. When the Section's only way in is through Fanning's abused girlfriend, Nikita and Michael are forced to use any means possible to secure her loyalties, but her emotional instability could prove fatal to both of them.

To flush out Vacek, Operations and Madeline order Michael to poison Elena, but Michael can't bring himself to do it. So Section poisons Elena anyway, while Michael is out on a mission, and her survival will depend on whether Vacek has enough conscience to visit his daughter in her time of need. Meanwhile, Section moves sleazy informant Mick Shtoppel in as Nikita's neighbor.

Nikita is sent back to Section One to destroy a new terrorist threat that only she can deal with which is a summit meeting of representatives from several terrorist groups. She is teamed up with a new level 5 operative, Marco O'Brien. O'Brien was the police officer recruited four years earlier because of a mistake Nikita made, a fact that O'Brien has not forgotten. Nikita finds that besides the terrorists, she must deal with O'Brien & the hostility of much of Section personnel because of her role in Center's evaluation of Section.

Egram Petrosian, the former Section deep cover agent rescued by Section One, takes over and promotes Nikita to second in command when Operations is seriously wounded by an insane operative.

A new operative with a photographic memory is brought in to ""remember"" the directory of a terrorist organization. When he is made a permanent recruit, Nikita looks into her own recruitment, wondering if it was planned or not.

Section One is finally moving hard against Red Cell. Their objective is to capture Chief Strategist (Madeline's opposite) in Red Cell, a man code-named Leon. Once captured, Leon and Madeline begin a dangerous game of mental and emotional cat and mouse. Is Madeline actually developing an emotional attachment to Leon that is interfering with her objective? And what is with the incision that Birkoff discovers behind Madeline's ear? Meanwhile, Birkoff is giving Walter the cold shoulder, and continues to investigate the whereabouts of his twin brother, Jason Crawford.

Nikita continues on the mission she was sent on in, "Man in the Middle," which is to marry Helmut Volker, a man with several ties to Red Cell, but she finds out that she is not the only one with secrets, her new husband has a big secret of his own.

Section's newest target is the son of a wealthy industrialist, by the name of Helmut Volker, who is supplying drugs at his parties when not funneling arms to Red Cell. The twist is Operations and Madeline have figured out that Michael has "restored" Nikita, so Operations uses this operation to once again drive a wedge between Michael and Nikita. Helmut Volker must marry if he is ever to inherit hit father's business, so Operations orders Nikita to marry Helmut when he proposes! Meanwhile, Michael does everything he can to prevent that from happening.

Glass Curtain is a high-tech terrorist organization that attracts new members via internet chat rooms. Posing as a new recruit, Nikita is taken to Glass Curtain headquarters, where she discovers that Michael's wife Simone is being held hostage. A former Section One operative, Simone was believed killed years before. Now, Michael's continued love for Simone may threaten the success of Section One's attempted infiltration of Glass Curtain.

On an assignment to capture a Red Cell agent known as Jenna, with valuable information, Nikita is arrested and brought to jail in order to serve time, where Jenna is also serving time. But she is forced to betray the trust she has with Jenna when she must escape the jail along with her, only for Jenna to be captured and interrogated.

After effectively losing his wife and son forever, Michael's performance begins to seriously suffer. So as Nikita seeks to restore Michael's will to live and to protect him from Section's latest enemy, Operations and Madeline bicker over what is the best strategy to handle fragile Michael. Meanwhile, Birkoff goes to Walter about a file Birkoff discovers, a file that contains incriminating evidence on Operations.

This time, Section is out to get an outfit by the name of The Alliance, and Section's way in is a psychotic courier by the name of Jan Bailin. Bailin has other plans and she kills herself before the Section can use her. So, as a backup, Section employs a meek, terminally ill lookalike for Bailin by the name of Sarah Gerrard. As she trains her, Nikita starts to get suspicious, did Section purposely make Sarah ill to make it easier for Section to convince Sarah to work for them? And if so, will Section even let Sarah live if she completes the mission?

Section believes that an imprisoned terrorist leader is ordering an attack through his lawyer. Nikita and Michael go undercover as a couple, and Nikita is supposed to be a psychic. The terrorist's lawyer asks Nikita to contact his dead son, but Nikita is shocked to discover something else.

With Michael's help, Nikita survived the destruction of a Freedom League hideout in the first season's final episode. Since then, she has been on the run from Section One. While working as a waitress, Nikita is captured by the Freedom League and used as bait to lure Section One into a trap. During a raid by a Section team led by Michael, Nikita saves Michael's life and they manage to escape together. Later, on an abandoned ship, Nikita and Michael share a night of passion. However, Michael's lies about Nikita's whereabouts are in danger of being exposed.

Nikita, a girl living on the streets, is wrongly accused of a murder she did not commit and sentenced to life in prison. After the government arranges to fake her suicide, Nikita wakes up at Section One, a top-secret agency that aims to train her to become an anti-terrorist operative. Nikita wants to resist, but in order to stay alive, she has no choice, but to comply with their plans.

Michael discovers that Adrian's mind is not blank as he thought it is. Together they try to save George from Operations and Madeline's attempt to assassinate him. Meanwhile, Michael kidnaps Nikita in a futile effort to reason with her.

Birkoff may have stumbled on Section One's biggest coups yet, a chance to nab a top Red Cell operative by the name of "The Cardinal", who has eluded Section One for more than 15 years. Unfortunately, Birkoff's arch-nemesis Greg Hillinger is convinced that Birkoff is wrong, and Hillinger convinces George that Operations and Section One are walking into a trap. Based on Hillinger's intellect, George moves against Operations on the assumption that the operation against The Cardinal is bogus. Is Birkoff right after all? And if Birkoff is wrong, is this the end of Operations, and Birkoff too?

After Substation three is destroyed by self-destruct, Section One investigates and finds a trace to Red Cell. What they also discover is that Red Cell has been taking similar blows. Operations decides to become allies and for each other to send top-notch agents. Operations sends Madeline, though Operations is willing to risk her.

After someone breaches Section and breaks into her room, Nikita is more determined than ever to find out the truth about why she was brought into Section. She arranges to get at Mr. Jones personally by having him go out as "Mick Schtoppel" on a mission against an arms dealer with ties to The Collective, by the name of Massima Valenti. Was Operations telling the truth in "Deja Vu All Over Again" when he told Nikita that "Mr. Jones is not what he appears to be...?" Is Nikita making a big mistake in pushing the issue? Meanwhile, Quinn continues to put the "moves" on Operations, but what is she really up to?

Brothers Karl and Simon Peruze are responsible for some of the most vicious attacks on civilians ever recorded. Eliminating both of them proves difficult, since neither brother would ever give up the other. Section One kidnaps Karl, wipes clean his short-term memory, and places Nikita with him when he comes to, so she can pose as his fiancee and lead Section to Simon. Strangely, the more Nikita learns about Karl's cruel history, the more she is drawn to him, falling in love with him. However, Nikita's slowly dawning realization that her mind is being controlled by Section threatens to unravel the entire mission.

A Section operative known as Terry fails a mission and admits to Nikita, the cause was her pregnancy. When she is teamed up with Nikita and Michael, she plans to escape from Section, and Nikita must choose a side.