In Las Vegas, Nevada, after doing some webcam work with her clothes off revealing her sexy body, Niki Sanders prepares for the day with her young son, Micah, but when thugs break in, she leaves. After Niki visits her son's private school, the principal gives her bad news about Micah’s tuition; she leaves and sees her reflection moving differently than she is. Haunted by what she sees, she yells at the image to leave her alone, much to the confusion of her son.
Later taking her son to her friend Tina's house, Niki talks with the woman about her situation. She explains that Mr. Linderman, who appears to be a loan shark with mafia connections, sent the home invaders seen earlier. Niki borrowed tens of thousands of dollars from him for Micah’s tuition, which has now been lost. Niki also tries to tell her friend about this strange "other" she hears and sees, but her friend fails to understand. Frustrated, Niki simply leaves. Arriving home, Niki finds the pinhole camera Micah made for watching the upcoming solar eclipse (that appears in Isaac Mendez's first painting, and is witnessed by several characters throughout the second episode). While looking through the camera she realizes the thugs are still there, and attempts to escape, but fails. The thugs then propose she perform for them on camera, then force her to do so. When she objects, the thug strikes her.
Niki awakens sometime later to find the mutilated bodies of the thugs. Even more shocking, Niki looks into the mirror to see her reflection covered in blood — even though she isn't — and gesturing for her to keep quiet.
Niki grabs her video camera and leaves to pick up her son. However, when she watches the videotape, the image dissolves into static while the audio records the sounds of the thugs screaming and being killed. She experiences another blackout and awakens four hours later (in a different location and a new change of clothes) when Micah calls her a second time.
When she returns to her house to clean up the bodies, she discovers her garage has already been cleaned (even her webcam setup has been cleared away) and a key is hanging from the ceiling. She catches her reflection, which motions to a classic Cadillac parked across the street. Finding that the key fits, she discovers the registration, some months old, is in her name, and the thugs' bodies are in the trunk, along with a map. She gathers up Micah and sets out into the desert, following the map.
Niki follows the map and begins burying the bodies in an unnamed desert in Nevada. To her horror, she discovers the skeletal remains of a man wearing a skull ring, alike to the ones worn by the crew that associated with D.L. Hawkins, Niki's estranged husband and Micah's father.
Niki takes Micah to visit D.L.'s mother's house to confront her about her interference in Micah's life and about the ring she found. D.L.'s mother believes her son was framed for the theft of two million dollars and the murder of his crew and that he is on the lam. Micah then lets slip that he might know how to contact his father. However, before they can get anywhere, Niki is pulled over by a police officer who is working for Linderman and brought to see him.
Niki and Micah meet with Miss Sakamoto, Linderman's assistant. Mr. Linderman will forgive Niki's debt if she seduces a politician who is courting Linderman's favor as "insurance". Shortly afterward, Niki went back to Tina's with Micah. Tina asked Niki if she's still seeing the other person in the mirror but then Tina just laughed it off and told Niki that it's just old age. Tina left the room and Niki talked with Micah, who revealed that he knows about his mom's webcam business and what Mr. Linderman wants her to do to repay the debt. The scene ends with a limo arriving at the door to bring Niki back to the casino. There, Niki ran into Nathan and had a surprisingly good time with him but did not go through with the deal. She is assaulted by one of Linderman's lackeys in the elevator where she reverts to her alter ego, beats up the lackey, and returns to Nathan's hotel room to sleep with him.
Niki is woken up by Nathan's campaign manager who asks her what she did with Nathan. Miss Sakamoto tells the man that they will take care of finding Nathan and he leaves. Miss Sakamoto tells Niki that she is debt-free now that she has seduced Nathan, and shows her the tape of their liaison. Niki leaves and finds police at her home looking for her husband, D.L. Hawkins, who seems to have been seen in the area. After someone attempts to break into Niki's house, they realize it is only Ando Masahashi who wants to meet Niki as he is a big fan. Niki tells them that he should just go home and the cops also leave but stay in the neighborhood to look out for D.L. Once the police are gone, D.L. appears in the house and hides in Niki's bedroom.
Niki finds D.L. in her house. They argue for a while about D.L. having left them but ultimately try to work things out. Niki accompanies D.L. when he tries to find the man suspected of laundering the $2 million he was framed for, but instead they only find a room with several dead men. Later Niki's alternate personality reveals that it was she that stole the $2 million from Mr. Linderman, killed D.L.'s crew, and killed the men D.L. took her to see previously all in order to cover up the theft. Her alternate personality tells her that she needs to take Micah and leave because when D.L. finds out he's going to take Micah, the money, and might even kill Niki. She retrieves a briefcase full of money and a gun from the crawlspace above her room, but it caught by D.L. after she exits. Her alternate personality takes over and they fight with Niki throwing D.L. into a dresser. She appears to be at an advantage until D.L. uses his power to reach into her abdomen, causing her to fall unconscious.
Niki regains consciousness on the floor of her bedroom. She immediately searches for Micah but finds him missing. Tina arrives and Niki tells her what happened. She explains about Jessica and says that she wishes Jessica would take over so she can get Micah back. Tina tries to tell her that Jessica isn't real.
Niki calls Nathan Petrelli and asks for help, explaining that her husband has taken her son, but Nathan refuses to help her. Enraged, Niki breaks a mirror, and Jessica takes over, scaring away Tina.
As Jessica prepares to go after D.L., Niki gazes at her helplessly from a truck's side view mirror.
Niki attends an AA meeting. While speaking to the assembled group about her situation, and wearing the clothing and name tag from her Las Vegas casino worker position, she says she is one year sober, but the difficulties in her life are making her want to drink again. She notices her father, Hal Sanders, at the back of the meeting. After the meeting, he tells her he would like to be a bigger part of her life.
Niki visits the grave of her sister Jessica where she tells D.L. that Hal is back. They decide to have him over for dinner. At the dinner, Hal alludes to a bad past between Niki and him, but Niki doesn't seem to remember what he is talking about. He says he owes her more than an apology. Hal gives Niki a check to "make her life easier". When he leaves Niki looks into a mirror and suddenly changes attitude from upset to determined.
After D.L. and Micah manage to evade Jessica, Niki stares at Jessica reproachfully from a reflection in D.L.'s car's window. When Jessica discovers D.L.'s bloody jacket, Niki attempts to reassert control. Catching Jessica's reflection in a mud puddle, she argues with her about what she's trying to do to D.L. They hear Micah call out, and take off after him.
At the cabin, Jessica pretends to be Niki, but D.L. is waiting for her. As they struggle, Jessica pushes Micah roughly aside into a pile of rocks. Seeing him hurt, Niki is able to take control, and apologizes to both Micah and D.L. As they walk away from the cabin, Niki realizes that Jessica is too great of a threat to D.L. and Micah. When Micah slips and D.L. goes to help him, Niki seizes the opportunity. Leaving the money behind, she approaches a Utah highway patrolman across the road and turns herself in for murder.
Niki is in jail pending her trial for the murders of D.L.'s crew and the theft of Linderman's money. During the two weeks since she surrendered herself to the police, her alter-ego Jessica has injured at least one of her guards. While speaking with her attorney, Jessica manifests several times, encouraging the lawyer to plan an insanity defense. During a later visit with D.L. and Micah, she asks to be allowed to hug her son. A nervous guard swings his baton at her, but she (or Jessica) catches it and breaks it. The guards quickly take Niki out of the visiting area. She is later placed in a padded cell, wearing a straitjacket, and given an injection.
In her padded room, Niki receives a shot. When she awakens, she meets Dr. Witherson, who wants to meet Jessica, but Niki refuses. Dr. Witherson likewise refuses any more injections for Niki. Later, she receives a visit from D.L. in the cell. She tells D.L. that she will be in jail for a long time, and advises him how to raise Micah. When she meets with the doctor again, she considers allowing Jessica to meet the psychiatrist.
Dr. Witherson talks to Niki about her childhood. As Niki thinks about her sister, Jessica emerges. When Niki reemerges, Dr. Witherson is unconscious, and Niki asks to be taken back to her cell. The guard is all too happy to oblige. Later, Aron Malsky delivers news that arrangements have been made for Niki to be sent home. Once home, Jessica takes over again, leaving Niki trapped.
Jessica keeps Niki trapped by impersonating her, despite Niki's reasoning that not everybody will believe her. At Ridgway Jewelry, Niki begs Jessica to stop chasing Aron Malsky, but to no avail. Niki is horrified to learn that Jessica has been hired by Linderman as an assassin in exchange for being discharged from the Women's Correctional Facility. In the end, despite Matt Parkman's planned tactics due to Niki's distraction, Jessica succeedes in murdering Malsky.
Niki, though Jessica retains most control over their body, manages to leave the photo of Nathan given to her by Mr. Linderman on her pillow for D.L. to find. Jessica later confronts her about this then loads a gun and leaves. Fortunately for Niki, Jessica took the earlier take over for granted and later asserts herself. She uses the oppurtunity to confront Nathan in his room at the Corinthian. She tells him about Jessica's existence, the murder of Agents Quesada and Alonzo, and Linderman's awareness of the plan. Niki advises that Nathan run, taking his family with him, but Nathan refuses. Nathan then suggests that he just go and kill Linderman. Niki, seeing Nathan's determination, asks Nathan to punch her out and then take her gun. When asked why, Niki explains that it is to show that Jessica is not in control. Without a second thought, Nathan knocks her out.
After D.L. starts to head towards the Corinthian Casino in hopes of finding the abducted Micah, Niki speaks with Jessica through the mirror. Thinking she is to weak to save Micah , Niki pleads with Jessica to go with D.L and rescue Micah. After a moment of thought, Jessica agrees and leaves with D.L.
During Jessica and D.L.'s encounter with Linderman, Jessica is tempted with millions upon millions of dollars, so long as she kills D.L. Jessica realizes that all along, she had been fighting for a sense of security, and would do others harm without a second thought. But Niki wouldn't, and so she has her take control of the body. Niki returns, and reunites with D.L. in a passionate embrace. Linderman argues that her love for D.L. is nothing more than a fabrication, but seeing that there is no other choice, pulls a gun on Niki. Just as he is about to shoot, D.L. quickly jumps in front of her, taking the shot. While Linderman is distracted, however, D.L. kills him. Niki then takes the weakened D.L. in her arms, with him believing that she was the strong one all along, not Jessica.
Niki holds D.L. in her arms as he struggles to speak after he has been shot by Linderman. Soon they hear a banging on the door, presumably Linderman's guards. Niki tells D.L. that he can get them out of Linderman's office by phasing through the wall, but D.L. says he's not sure if he can. Niki helps D.L. over to the wall, and by the time the guards have broken down the door, Niki and D.L. are both gone.
Niki helps D.L. down the hallway of the building near Kirby Plaza, when D.L. protests, saying that he doesn't want to slow her down, and that she should go find Micah. Eventually Niki agrees, leaving him behind and telling him to stay right there. She goes into a room to find what appears to be Jessica sitting on the couch. She tells her to look at Micah, who is laying behind the couch, dead and apparently shot in the head, and that it is all Niki's fault. She then proceeds to assault Niki, punching and kicking, and eventually hitting her hard enough into a mirror that it shatters with the impact. Niki falls down among the shards of mirror, and sees Jessica in the reflection. This Jessica tells her that the Jessica standing over her isn't really her, and that she should fight back. Niki tells Jessica that she doesn't have the strength, and when the other Jessica leans over and asks who she's talking to, Niki punches her hard enough to send her across the room, sprawled on the floor, where she turns back into her real self, Candice. (This is Niki's first demonstration of enhanced strength.) Micah's corpse also disappears, showing that it was also part of the illusion conjured by Candice. Niki then hears Micah calling for her, and she runs across the hall to a room where Micah's voice is calling out from. He tells her the door is locked, but she simply yanks it open with her newly developed strength. Micah asks Niki if it's really her, since he knows about Candice's power, as well as Jessica. Niki looks in the mirror behind Micah and sees only herself looking back (indicating that Jessica is gone for good) and tells him it's just her.
Niki and Micah later find D.L. where Niki left him, only slumped down by the elevator. Mohinder and Molly are there as well. Niki picks up D.L. and get into the elevator with everyone else and ride down.
Outside, Sylar and Peter Petrelli are fighting. Right as Sylar, using telekinesis, picks up a parking meter to beat Peter with, Niki runs and takes it from him and assaults him with it. Micah yells to her that D.L. needs them, and Niki hesitates, not knowing which way to go. Peter tells her that he'll be fine, and Niki reunites with her family. Later, when Nathan shows up and flies off with Peter into the sky, Niki watches with her family below, wondering what happened to them.