Chauncey, the Duc de Langeais, is in a field when he is approached by a boy with dark hair. They boy questions his lineage, but Chauncey refuses to acknowledge being any different than he was knew. The boy tells him that his real father was a fallen angel, making him Nephil. The boy refuses to leave and gives Chauncey a sick feeling until he swears fealty to him. Chauncey does this begrudgingly and is told to return the next year during the Hebrew month of Cheshvan. The boy leaves showing marks on his back from where his wings used to be.
Nora goes to biology class and finds Ken and Barbie dolls on the chalk board with indicating that they will be starting sex ed. The teacher, who is also the basketball coach makes them change their seats so that they are all with someone they don’t know. He wants them to interview each other. Nora’s partner is a guy named Patch who seems to know everything about her already. She is annoyed by him especially since she doesn’t get a chance to ask him any questions. When she points this out after class, he writes his number on her hand. She claims that she won’t call. Her old lab partner and best friend Vee also complains about her new partner.
Nora lives with her mom is out of town a lot for work. He father was murdered a while ago. She is used to being alone in the house. She calls Patch so that she can get her biology homework done, but he hangs up on her. She drives out to the pool hall he said he was at and dodges the doorman to find Patch. The doorman chases her, but Patch says that she’s with him and he lets it go. She tries to interview him, but he just keeps hitting on her in a crude manner. Later that night, Nora wakes up thinking that something is at her window. When she looks, nothing is there.
After talking with the house keeper for a while, Nora leaves with Vee for Delphic Coast Park. They go on a couple of rides together and then go find Elliot and Jules in the arcade. Nora notices that Patch is there as well. While Nora tries to ignore him, Vee points him out to Elliot, who suggests that he go talk to him. Nora tries to defuse the situation by going to talk to Patch. He tries to get her to ditch on her double date, but refuses. Patch speaks inside her mind again and she asks him about it. He acts like she’s crazy and tells her to meet him at the archangel later.
Elliot goes off to find Jules and shortly after Nora goes to get some cotton candy. She looks back and sees a hooded figure, but when she looks back again, it is gone. In her distracted confusion, she runs into Patch. He tells her that if she rides the Archangel with him and doesn’t scream, he’ll tell her everything. Considering her fear of heights, Nora does pretty well until she notices that her seatbelt is undone. She tries to refasten it, but gets slammed against the door, which flies open. Nora thinks that she is falling out of the ride, but it turns out she is just fine. Patch leaves her confused once again.
When Nora gets back to the arcade, she can’t find Elliot or Vee. Patch follows her around while she looks for them. She realizes that Vee must be waiting for her out by the car, but after searching the entire lot, she realizes that she was alone. Nora accepts Patch’s offer to take her home on his motorcycle. When they get there, Patch has Nora’s keys, telling her that she dropped them at the arcade. Nora can’t get the keys to work, but Patch does. He teaches her how to make tacos and afterwards they do the dishes together. They flirt and Nora ends up on the counter with Patch kissing her shoulder. Her mom calls and she tells Patch that he has to leave. He does, reminding her of an invite to a party the next night.
Vee calls Nora in the morning waking her up. She guesses that Patch kissed her and starts asking for details. Nora doesn’t really want to talk about it. They make plans for later. After hanging up with Vee, Nora remembers that her cell phone is supposed to be dead. Later while shopping, Nora notices the hooded figure following her again. Vee goes out in Nora’s jacket and the figure follows with a feminine walk. Nora goes to the car to follow. Her windshield is hit by her umbrella that Vee had been carrying. She gets out of the car and finds that Vee has been attacked and robbed. Nora goes back to the car and calls 911.
Back at school, Nora is waiting for the day to pass so that she can visit Vee in the hospital. She notices that Patch is absent. Her teacher gives her a note to go and see the new school psychologist, Miss Greene. She does and she asks the same old questions about how she is dealing with her father’s death. She then tells Nora that she is only to tutor Patch on school property with supervision, but the reason cannot be discussed. Nora decides to go to the library to work on homework. She ends up on a computer and reads an article about a girl, Kjirsten, that supposedly hung herself in the woods. Elliot was questioned before the suicide note was found. Elliot comes in and Nora tries to hide the article that she was reading. He wants to take her out for dinner, but she comes up with some excuses and leaves.
Nora goes to the hospital to visit Vee. Her friend is a little loopy from the drugs, but becomes more normal after a little time. Nora asks about the attack and whether or not the guy would match Elliot’s description. Vee says that the person that attacked her was more like Patch than Elliot. Nora tries to tell Vee about the article she read in the library, but Vee’s painkillers kick in again. Nora goes home.
To do some investigating, Nora and Vee go to the restaurant where Patch works on his night off. When they get there Vee informs Nora that she has been dating Jules and invited him and Elliot to join them. However, Jules is absent because he is sick. They order their drinks and Nora slips off to change into her disguise so that she can question the bar tender about Patch. She doesn’t get too much useful information, but she does find out that Patch is currently there and working. She hurries off to the bathroom, locking the door behind her, to change back into her regular clothes. Patch is behind her and starts teasing her about her interrogation list. The locked door starts rattling and Patch leaves Nora in the bathroom wondering how he got in. Nora goes back to the table, claiming to be sick.
Nora isn’t home long before her mom has to leave for work. She goes upstairs to change and sees her room has been rummaged through. The guy in the ski mask is there and jumps out the window. She calls the police, but everything is back to normal by the time they get there.
The next day in biology, Nora and Vee are caught talking during an assignment. The teacher makes them switch lab partners and Nora is paired with Patch. After class, she goes to see Miss Greene. The psychiatrist asks Nora why she had Patch take her home from Delphic Park the previous Saturday. Nora explains and Miss Greene tells her to keep her distance from him.
Nora walks to the library alone after school. On her way out, she gets into a verbal fight with Marcia and decides to use the back exit. Patch is in the dark alley that Nora is walking down and confronts her. Nora starts asking him questions, but he only gives vague answers. He offers a ride home and she decides that it is probably safer than walking alone in the dark. Patch asks her out and says he’ll pick her up at five on Saturday.
On Saturday, Nora starts getting ready for her date with Patch. The police arrive and ask her some questions about her fight with Marcia. Nora finds out that she was beaten up. They leave and Patch arrives. He takes her to Bo’s Arcade to shoot pool. Patch’s friend Rixon shows up. The two guys fight a little and Patch’s shirt is ripped. Rixon gives him his sweatshirt. While Patch is changing, she sees an upside V-shaped scar on his back. Shortly after, they leave and Patch stops at an eatery. He goes in to get food and Nora takes the opportunity to search the car. She finds a flashlight with blood on it. Patch returns and explains it is not blood, but from paintball. He takes her home and gives her a snow globe containing Delphic Park. Nora’s mom shows up and questions him a little before he leaves.
While on the phone with Vee, Nora remembers where she has seen Patch’s scar before: the Arch Angel ride at Delphic Park. She researches fallen angels and finds out that they can speak to people’s minds and inhabit their bodies for two weeks during Cheshvan, a month with no Jewish holidays. The child of a fallen angel and a human is a Nephilim.
The next morning, Nora answers the door to find Elliot on the other side and drunk. He begs her to go camping with him, Jules, and Vee. When Nora declines, he gets angry and shoves her against the house. Her mom shows up and he lets her go, telling her that she will regret her decision not to go. Nora calls Vee and explains the situation.
Nora drives out to Portland and visits the diner where Kjirsten worked before her death. After ordering a large amount of food and promising to leave a hefty tip, The waitress tells Nora what she knows. Elliot bought Kjirsten her apartment. Jules and Elliot came in one day. Jules had failed a test and Elliot was so mad about it that he stormed out.
Vee texts Nora that she is at a party in Portland with Elliot and Jules, who just ran out to get something. Nora abandons her bus and starts heading to where Vee is. Along the way, she gets lost and sells her coat and hat to a bag lady for directions. She starts walking down an alley in the freezing whether when she hears something. A black sedan pulls up and kills the bag lady. Nora goes back for her phone, which she left in her coat pocket, but it is gone and so is the bag lady. She goes to a phone booth and calls Patch for a ride. He picks her up and starts taking her back to Coldwater. His jeep breaks down on the way and they decide to walk to the next exit.
The winter storm picks up and Nora and Patch find a motel. Their power and phones are out, so they end up having to rent a room. They each shower and leave their clothes out to dry. Nora sees Patch’s scar and touches it. She is sucked into a vision of his past from before he knew her. Dabria, his ex-girlfirend, comes to tell him that if he saves someone’s life, he will become a guardian angel. She tells him to give up on the book of Enoch because what he is trying to do isn’t right. He asks for the name of the person that he’s supposed to save. Dabria accidently lets Nora’s name slip out. She then sees Patch trying to kill her. Nora returns and is scared. Patch explains that he tried to kill her, but couldn’t go through with it. Nora asks to touch his scars again, to show a sign of trust. He complies. She sees Patch talking with Rixon, trying to make a decision. As it turns out, the body of a fallen angel can’t feel anything. He can either save a human life and become a guardian angel or kill his human vassel (the human he inhabits two weeks of the year during Cheshvan) and become human. Rixon says that he doesn’t believe the second option is anything more than a fairy tale. When she comes back to the present, Patch explains that he fell because he fell in love with a human girl thought it would make him human. He doesn’t want to become a guardian angel. Nora tells him that Dabria is working at the school and Patch decides that he needs to go check out her intentions.
Patch takes Nora home and leaves her to search the school. Dabria shows up wanting to kill Nora so that Patch will return to her. She explains that if Patch kills Nora, the female descendant of his vassel, Chauncey, he will become human according to the Book of Enoch. Dabria starts burning down the house to assure that Nora will die. Nora calls the police. Patch shows up and tells her to get in his Jeep and drive to Delphic Park. She starts driving and calls Vee, who is not answering. She calls Vee’s parent’s phone and her mom tells her that Vee is out at a movie. Nora decides to look for her.
Starting at the theater, Nora buys a ticket and goes in looking for her friend. She sits down in a movie and Patch shows up behind her. She tells him to go away (to the annoyance of the people near her) and he refuses. She storms into the girls bathroom and he follows her. He tells her that he doesn’t want to sacrifice her, that he actually wants to be with her. He eventually convinces her. Vee calls and interrupts their kissing, wanting Nora to come to the school to play hide and seek with her, Jules, and Elliot. Elliot comes over the phone and threatens Vee’s life if Nora doesn’t show.
Patch want to go help Vee and will only let Nora go if she promises to listen to him. When they get out to Patch’s Jeep, the tires are flat from being stabbed. Patch wants to steal a car, but Nora talks him out of it. She goes up to a guy that she used to tutor and asks to borrow his car. Patch pays him off when he says no. They get to the school and Nora waits in the car while Patch goes to check things out.
Nora gets a call from Elliot, letting her know that he can see her from a second story window. She goes into the darkened school and first finds Jules’ body. She continues along to find Elliot dying in the library. Just as she’s leaving the library, Jules comes up to her. She runs to the biology room and grabs a scalpel before he comes in. He temporarily disables her and tells her that he is really Chauncey, Patch’s vessel. He wants to hurt Nora (whom Patch loves) to get back at him for using his body for two weeks of every year since he was 16 (Nephilim are immortal). Nora is able to stab him with the scalpel, and after some scuffling, he collapses to the ground.
Going up to the top floor of the school, Nora finds Vee in the eZine classroom. She gets her out and tells her that they are going to get out of the school, split up, and run for help. Chauncey finds them before they can get out. Nora tells Vee to run for help and she listens. Nora heads for the gym, figuring that she can hide in the locker room. However the door to the locker room is locked. Chauncey catches up with her and has a gun pointed at her head. Patch enters her body to try to choke him out. Before he passes out, Patch is forced to leave Nora’s body. She can’t get out the door, so she goes up a ladder to the rafters and an air shaft. She starts climbing and the ladder starts to fall. Patch’s voice comes in her head and tells her that it is just an illusion. She listens and makes it to the rafters, but Chauncey is following. She decides to sacrifice herself rather than letting Chauncey kill her and throws herself off of the rafters.
Nora wakes up in bed, surprised that she’s not dead. Patch explains that he turned down her sacrifice because he didn’t see the point in being human if she was dead. The sacrifice killed Chauncey, and he should’ve come back to life with she did. However, he didn’t have a soul to reanimate his body. Nora’s mom comes home and starts freaking out when she sees the damage to the house.
Nora talks to Vee and says that she doesn’t remember much of what happened. Vee tells her that Patch called her to tell her what happened, but she still thinks that Patch killed Jules. The police come by to get a statement about the fire and Nora tells them most of the truth about Miss Greene. Nora’s mom is having a security system installed in the house and Patch comes to hook it all up, saying that it is his new job.