DAY ONE

Along with the rest of Jack’s inner circle at CTU, Nina is called in at midnight to investigate a potential threat on Senator Palmer’s life. She senses that Jack is preoccupied with something at home, and when she asks him about it, he dismisses her concern. Nina is also worried about Jack’s shutting her out of important discussions on the case and his subsequent stepping over legal boundaries in the investigation. He rebukes her accusations. Yet when Jack asks her to illegally track information, Nina appeals to current boyfriend Tony for his help -- in assisting Jack.

After Tony suspects that Jack's meeting with Walsh was not on the level, Nina lies to him about what went on. With Jack out of the office, Nina assists Teri in finding the owner of the furniture store. It is an awkward conversation with her ex-lover's wife.

While Jamey mounts evidence of a betrayal, Jack stalls Nina. He brings up their past affair, and questions whether she is still dating Tony. Nina has an alibi -- she was with Jack when the files were supposedly downloaded onto the key card. Although Nina is innocent, she is angry with Jack for even suspecting that she is a turncoat.

Jack explains what has been happening, and tells Nina she is one of the only ones he can trust. She covers for him when George Mason comes to question her, and she encourages Jamey to do the same. Yet when Tony admits that he was the one to call in Mason, Nina suspects he is doing it out of jealousy over Jack.

Nina gets Jack access to Penticoff. Then, without a warrant, she traces a pay phone for Penticoff's important call from Gaines. When the call instead rings on a waiting cell phone, she is unable to trace it. Nina tells Tony that she will never trust him after he turned Jack in.

When Jack brings in the car with the body in the trunk, Nina accelerates the forensic identifying of the body. She looks the other way when Jack requisitions a helicopter, and Tony lets her know that he is aware of it. She gets Jamey to help with the dead body, and, much to Jamey's chagrin, decides to bring in an outside consultant to work on the key card instead. When she can't find Jack, Nina phones Teri with news that the corpse's name is Alan York.

Jack arrives at CTU, and Nina barrages him with questions about his peculiar behavior. She confronts him about switching the key card, and Jack pulls his gun on her. He takes her to an empty location and shoots her. Yet the jacket he made her put on at CTU was bulletproof. She wakes up later and walks off unharmed.

Nina finds a phone and tries to call Jamey. She gets Tony instead, and explains to him what has been going on. After Tony catches Jamey in a lie, Nina is convinced that Jamey is the leak inside CTU. Tony sends a car for Nina, and he takes her into a secure room. Tony wants to warn the Secret Service about Jack's being compromised, and Nina admits that they must do so, regardless of Jack's predicament. She and Tony capture Jamey, but Jamey does not reveal her employer. When they see the near threat against Palmer on television, Nina and Tony order Jamey to notify her unknown employer that Jack was arrested only on CTU's orders.

When Jack phones in, he explains to Nina about putting her life in danger. He asks her to get Jamey's son to help persuade Jamey to talk. Nina assigns Milo to take over Jamey's work, and considers the possibility of briefing Milo on Jack's situation. Nina and Tony discover that Jamey has tried to commit suicide. As they attempt to rescue her, they see Gaines calling Jamey.

Nina connects Teri to Jack, and uneasily listens in as he pledges his love for his family. She has Milo attempt to trace the location of the call. Nina is passed over when a replacement is brought in to run CTU in Jack's absence. Nina does not get along with the woman, who used to work under her and knows about Nina's past relationship with Jack.

While keeping Alberta Green at bay, Nina performs covert research for Jack on Cofell and Kevin Carroll. With no hard evidence incriminating the men, Nina thinks that perhaps Jack has captured an innocent man. Tony suggests that he and Nina come clean to Alberta, but Nina wants to keep the secret to protect Jack.

Nina sends Jack satellite photos of Gaines' compound and tries to get him to allow her to send backup. Jack refuses. Tony agrees to keep quiet for Nina's behalf. Alberta Green punishes Nina and Tony to get them to admit to conspiring with Jack. They both reveal nothing, and are suspended. After Jack notifies Green of his actions, she removes the suspension. Nina thanks Tony for standing beside her.

Alberta Green has Nina and Tony question Jamey's mother about large-scale deposits to her bank account. The woman admits that they are from Jamey, but doesn't know where her daughter received the money. When Tony learns that the money came from a company in Belgrade, Nina remembers that Jack had thought that there might have been a connection to a past assignment there. She and Tony find that a second shooter has left Belgrade for Los Angeles.

When Jack begs Nina to protect his wife and daughter, she must get permission from Alberta Green to do so. At the clinic where the Bauers are being treated, Nina meets a man who claims to be an FBI agent. She later learns he is not with the FBI, but he has disappeared from the clinic. Suspecting a threat, she orders Teri and Kim to be moved to the safe house, and asks for a fingerprint dusting of the room that the supposed agent was in. No fingerprints are found because a professional has removed them.

Nina hurries Teri and Kim to the safe house. While she is interrogating Teri, she gives away clues about her personal relationship with Jack. Teri senses that Nina is the one Jack was sleeping with when they were separated, and Nina admits to it being a brief thing that Jack ended abruptly. Yet when Teri asks if Nina thought it was a mistake to get involved with him, she does not answer. Teri storms out of the interrogation. Jack tells Nina that his family is still in danger, but he doesn't want them to know of its seriousness.

In her questioning, Nina suspects that Kimberly may have feelings for Rick and is trying to cover for him. She mentions this to Teri, who slaps down the idea. While Nina tries to debrief her, Teri is antagonistic and still full of residual anger over Jack's affair with her. Nina gets nowhere in her interrogation, and brings in another agent to finish. Nina returns to CTU, telling Jack that she left his family in safe hands.

As she helps Jack prepare to nab Alexis Drazen, Nina is unsure whether Elizabeth Nash is fit to handle such a task. After Jack notices that something is wrong, Nina confesses that Teri figured out that they had been having an affair.

Nina accompanies Jack to the meeting place and sets up the CTU team surrounding the area. After describing more details of her conversation with Teri, she encourages Jack to call his wife. Yet he can't get through to the safe house. When a CTU agent with a grudge against Jack muddies the operation, Nina gets Mason involved to chastise the agent.

After the man is killed at California Plaza, Nina returns to CTU to dig up information on the location of the intended power outage. When she learns that both Teri and Kimberly are in jeopardy, she chastises Tony for not notifying her and blames herself for their disappearance. She calls Mason to get him to tell Jack, but he refuses. When Teri tries to call Jack herself, she can't get through because Mason turned off Jack's cell phone.

Nina has Tony bring Dr. Parslow to a clinic so that he can be questioned. She then grills Mason at why he is still keeping the facts about Teri and Kim's disappearance a secret from Jack.

Nina is alarmed to hear that Mason is willing to sacrifice Jack to bring an end to the mission at the detention center. She tells Teri that Jack is in danger, but won't give her specifics.

After CTU refuses to admit that Victor is even alive, Nina admonishes Mason for not making the trade to save Jack. She takes it upon herself to contact Palmer, and he makes the call that convinces Mason. When she can not admit the truth to Teri about Kim's abduction, Nina questions her own resolve. Yet Tony assures her that she is indeed a good leader, and Nina is appreciative of his kind words. After placing a homing device on Alexis Drazen, Nina's trace is stopped when Drazen's guard finds the device.

Nina finally tells Teri that Kim is in danger, but lets her know that Jack is working to save her. After it is learned that Mason once researched the underground prison, Nina and Tony suspect that he may be the mole inside CTU. She orders Tony to shut down Mason's computer access. When Jack phones, he does not give his whereabouts, nor does he permit Nina to help him. Mason informs Nina and Tony that Palmer actually survived the bomb incident, despite reports of his death. Nina secretly calls Andre Drazen. Speaking in Serbian and identifying herself as "Yelena," she tells Andre that Palmer is really alive. Nina is revealed to be the traitor working against Jack.

When Jack learns that the Drazens know the truth about Palmer, he asks Nina to find out who the mole is inside CTU. He tells her that the Drazens want to trade him for Kimberly. Nina does not let on to him that Kim is actually safely in CTU's protection. She wants Jack to give himself up to the Drazens. Nina alerts Andre that Kim is being brought to CTU. In order to make Jack come forward, Victor orders Nina to inform him that Kimberly is dead. She does, opening herself up to getting caught. Nina calls her contact and prepares her escape, killing a number of CTU employees in the process. Yet when Teri accidentally sees one of the bodies, Nina ties her up and tapes her mouth. She tells Teri that she is only locking her inside the room, but kills her instead. Nina drives out of the garage, but Jack storms toward her in his car. They shoot at each other, and Nina swerves, hitting a parked car. Nina admits that she is working on behalf of someone other than Drazen, but that if Jack kills her, he will never learn who her employer is. Jack is about to shoot Nina for her betrayal, but he is goaded by Tony and Mason to release her. Tony watches as Nina is taken away in handcuffs.

DAY TWO

Nina tells the agents at the airbase that Jack drugged Miller to have free reign over her, and they warn Jack that they will protect Nina. Jack makes Nina strip her prison wear in front of him. She is hesitant to meet Faheen herself because she thinks he will kill her and then shoot himself. Jack assures her that he will guard Faheen’s life, but makes no mention of saving Nina. Nina leads the team of agents to a store and goes in to make contact with Faheen wearing a video camera on her necklace. She tells Faheen that she has escaped prison, and when he hugs her, the camera goes out. Jack orders the SWAT team to raid the store, and they find that Nina has disappeared. She gets trapped in the basement, and Jack arrests her.

After being caught by Jack, Nina tries to get Faheen to give her information. Faheen, however, won’t budge. Jack puts Nina and Faheen back on a plane to Los Angeles, where she persists in attempting to persuade Faheen to give the federal agents the information they are looking for. Nina tells Faheen that she can save his family from being rounded up by the U.S. military for his terrorist activities. Giving in, Faheen whispers something to her that is unintelligible to Michelle’s microphone. Unseen to anyone else, Nina has a shard of a gift card in her hand that she lifted while in Crescent Collectibles. She slits Faheen’s throat and kills him before Jack and the other agents are able to intervene. Telling Jack that she now is the only person who knows all the terrorists’ plans, Nina demands that she be taken to San Diego for extradition out of the country. Jack tells her that he will let her go once her information is substantiated. As they complete their journey, Jack recounts a memory of his wife, blaming Nina for the loss. Suddenly, there is an explosion, and the jet begins to plunge.

As the plane begins to go down, Nina will still not reveal what she knows about the bomb. She fears that, even if they survive the crash, Jack will kill her. After the crash, Jack revives Nina and they embark into the forest to set off a flare. They see a band of camouflaged soldiers kill the wounded Agent Phillips. Jack knows they are not from CTU, and he shoots one of the soldiers with the flare gun. Taking the soldier’s rifle, he hands Nina the ammo and they duck into a ravine. She guides him where to shoot and gives him clips to reload. Nina covertly slips one of the clips into her pocket and tells Jack that she has no more bullets. When he puts down the rifle, Nina grabs it and loads it with her hidden clip. Although the CTU team comes to their rescue, Nina takes Jack hostage and demands that she be connected to the President. Jack instructs the Search and Rescue team to obey her because she is the only one who knows where the bomb is. Nina requests from Palmer an advance pardon for her murder of Jack. Palmer reluctantly grants her demand, but asks her to wait until the bomb is found. Nina smugly says, “This isn’t how you thought it would end, is it Jack?”

While holding him hostage, Nina tells Jack that she only killed Teri because the woman had overheard her plans to escape. Jack begins to walk away from Nina, and she shoots at his feet with a warning to stay put. Yet Jack coerces her to follow him, and a sharpshooter in the distance is able to hit her in the hand with a bullet. CTU agents swarm Nina and take her captive. Jack whispers something in her ear that makes her shudder with fear.

DAY THREE

Nina emerges as a representative of the second bidder for the virus. Yet when she sees Jack there too, she is quick to doubt his motives because she knows he would never turn on CTU. Nina wants to leave, but her client would not approve of her losing the virus. She agrees to stay, and she wins the auction over Jack. Nina leaves, and the dealer will contact her once her funds are transferred.

After Nina receives instructions from Amador about where to pick up the virus she is caught by Jack at gunpoint. Nina manages to knock Jack out and tie him up. Jack persuades her that he has no one left in his life. All he wants is to take his share of the money and disappear. He offers Nina ten times what she would have been making to turn the virus over to the Salazars. Although Nina is suspicious, she wants to accept Jack’s generous offer. To test his claims of renouncing his former life, she kisses him.

Nina can tell from Jack’s kiss that he still despises her. She accuses him of working with CTU. Jack turns the tables on her and takes her hostage, explaining that he needs the money from the virus deal. Nina tries to convince Salazar that Jack is a mole, but he won’t listen. Jack makes her transfer the money to Amador and arrange a place to pick up the virus. Nina senses that Jack’s plan is falling apart, but even she is shocked when Salazar shoots his own brother for not going through with the transaction.

Nina tells Salazar that she can prove Jack is really working for CTU by pointing out the positions where agents would be hiding. Salazar sends two guards to check it out, but there is nothing there. He tells Nina that he will have her killed if she screws up the deal with Amador. She goes to make the exchange, and comes back with the briefcase holding the virus. Salazar grabs the briefcase, and he is about to kill Jack when a shot hits him from a nearby hill. Nina takes off into the woods.

Nina captures Chase in the woods, but Jack takes her hostage. She lets Jack know that she can help him find Alvers, a man who Amador uses for assistance. She gives Jack a code to dial that will contact Alvers, but instead the code enacts a worm that paralyzes the CTU computer system. In return for disabling the worm, Nina wants to be safely returned to Mexico. When the worm actually intensifies, Nina provides CTU with instructions to slow it down so that she has time to leverage her escape. But Jack refuses to give in to her demands, and after CTU stops the worm, the plane continues to Los Angeles with Nina in custody.

Nina is brought back to Los Angeles and all eyes are upon her when she is ushered into CTU. Tony tries to question her about Alvers, but Nina attempts to throw him off by referencing their past relationship. When Tony mentions that Alvers tested positive for HIV, Nina makes no expression. However, her quickened heart rate gives away that she once slept with Alvers. Nina reveals nothing else, so she is subjected to torture. As a needle is injected into her neck, she jerks her head back causing the needle to hit an artery. Nina’s neck begins to spout blood. She is transferred to the less secure clinic, and while the doctors give her an anesthesia drip, Nina plugs the tube and pretends to pass out from the sedative. When Tony leaves the room, Nina kills all the medics and guards and escapes into the building. Kim catches her in the CTU control room and threatens to shoot. Yet before Nina can fire back, she is shot in the shoulder by Jack. Jack dismisses Kim and kills Nina.