Nikita is assigned to get close to a money launderer in order to steal his data files. When she learns about his successful charity for troubled youth, she starts falling in love with him. However, when Section One admits to Nikita that the shelters are a front for a thriving child slave trade, Nikita's loyalties become divided.

Section One is assigned by the CIA to ""quietly"" deport Suba, a foreign anti-terrorist contact who is smuggling waste uranium out of the country for his own profit. The first attempt to capture him goes terribly awry, and Nikita is held responsible. Upon further investigation, Nikita discovers a traitor in the Section, but one who is being manipulated by Suba is holding his son hostage. Nikita must now decide whether to risk the wrath of Section One by rescuing the ""traitor's"" son.

Section One's computer security is breached and the directory of all their agents is stolen. Michael goes to Prague to reclaim the directory, but the man who stole it is killed by another terrorist seeking the directory for himself. Nikita discovers that it was randomly left with a civilian passenger on a Prague city bus, architect Gray Wellman. Nikita is assigned to Gray in order to get close to him and retrieve the directory, but when she starts falling for him, her actions not only threaten the mission, but Section One's very existence.

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.

While Nikita is reassigned to Special Operative Jurgen, Section is contacted by one of Freedom League's operatives in order to verify Nikita's story about her capture.

Operations orders a raid to capture the leader of a terrorist group, which turns out to be a sentient computer.

With Adrian's help, Nikita manages to breach the most sensitive area of Section and secure a file, code named Gemstone, which contains evidence which will bring down Operations and destroy Section One. Meanwhile, Operations forces Michael to identify the Section operative most likely to work with Adrian to undermine Section, Nikita. Michael confronts Nikita in order to try to find a way to protect her, but she denies any association with Adrian. Now Michael is forced to kidnap both Nikita and Adrian and bring them back to Section, knowing that Nikita and Adrian will be cancelled and that the incriminating Gemstone file will be permanently erased.

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.