Plot summary

March 1983. Los Alamos, New Mexico. A group of police cars, with sirens wailing, escort an ambulance to Los Alamos Memorial Hospital. They are carrying an unidentified 50-year old man with acid burns to the face. He is placed on a respirator because the toxic fumes from the acid have seared his lungs and thus compromised his ability to breathe. A Detective (Elias Koteas) attempts to speak with him, asking him to identify himself and wondering whether he is a part of a Satanic cult. He gets no reply. A nurse calls him to the front desk to take a telephone call from the receptionist in the lobby who reports that the man's daughter is asking about him. Hearing a sudden change in the beeping of his respirator, the nurse returns to the man's room and screams. The man has jumped out of his tenth floor window to his death, leaving only a note that reads: "I'm sory [sic] Abby".Two weeks earlier. Twelve-year-old Owen (Kodi Smit-McPhee) is sitting alone in the snow-covered courtyard of his apartment building, singing to himself, until his mother (Cara Buono) calls him for dinner. Owen's parents are in the process of a nasty divorce, and Owen is often left to eat alone and amuse himself by playing alone in his room. One evening, he notices a girl (Chloë Grace Moretz) about his age and her father (Richard Jenkins) moving into the apartment next door to his. Oddly, she is wearing no shoes.The next day at school, Owen is picked on as usual by three older boys -- Kenny (Dylan Minnette) and his friends Mark (Jimmy 'Jax' Pinchak) and Donald (Nicolai Dorian). Out of fear, wimpy Owen doesn't fight back, even though they give him a wedgie, causing him to urinate on himself. That evening, as he sits in the courtyard rehearsing knife attacks on his tormentors, he notices the new girl, Abby, watching him. She's not very friendly and tells him right off that they can't be friends. Not long afterwards, her father walks through the courtyard. It is revealed to the viewers, and what Owen doesn't know, is that he is not Abby's father...he is her 'renfield' and Abby is a vampire. It is his job to bring Abby fresh blood, which he gets by killing other humans. First he stalks them, then renders them unconscious, then he strings them up by the feet, slits their jugular veins, and catches the blood in a jug.Unfortunately, 'Father' is having problems securing blood for her. On his first kill after moving into the new apartment, he stalks a local all-night supermarket where he breaks into the car of a local woman. At a railroad crossing, he knocks her out, takes her to the woods, strings her up by her ankles, slices her throat wide open and drains her of her blood. But afterwards, he trips in the snow, spilling the blood on the ground. Consequently, Abby is beginning to get hungry and annoyed.The next evening, Abby and Owen run into each other again in the courtyard. Once again, he notices that Abby is not wearing shoes. What's more, her stomach is growling fiercely, and she smells bad. Still, Owen shares with her his Rubik's cube and shows her how to work it. After Owen has gone inside, Abby goes hunting. She waits in the shadows under a bridge. When a man walks by, she feigns falling and asks him to help her. The man picks her up, intending to carry her to her home. Suddenly Abby latches onto him and bites his neck. Father is livid when Abby tells him what she has done, but he dutifully cleans it up by dumping the victim's body into a small lake.The next morning as he leaves for school, Owen finds his Rubik's Cube in the courtyard, completely solved. That evening, Abby is waiting for him in the courtyard. This time, she is more friendly and takes the time to explain to Owen how she went about solving the puzzle. She also smells better, but it's odd that she cannot remember her birth date when Owen asks. Since Abby doesn't know her birth date, she doesn't celebrate her birthdays and gets no presents, so Owen offers her the Rubik's cube.The next day, while the class is supposed to be watching Romeo and Juliet, Owen is busy copying the symbols for Morse code. He is later confronted in the lavatory by Kenny, Mark, and Donald. Kenny asks what he was working on during class. When Owen refuses to show him, Kenny hits Owen with a metal antenna, raising a gash on his left cheek. Owen later tells his distant and non-attentive mother at dinner that he fell during recess.After dinner, Owen meets with Abby as usual in the apartment courtyard. When she sees the bandaid on Owen's cheek, he tells her the truth about what happened. She warns him that he must hit them back hard and then they'll stop. If they don't stop, Abby promises to help him. Owen shares with Abby the Morse code that he copied. That night, they practice tapping on the wall that separates their apartments. The next day at school, Owen signs up for the weight-lifting program. Later, he takes Abby to an arcade and to play Ms. Pacman. He offers her a Now & Later ("Have one now, save one for later") candy bar. At first, she refuses; then she tries one. When Owen finds her heaving on the sidewalk, he hugs her. Abby asks him whether or not he would still like her if she wasn't a girl. "I guess so," Owen replies, not quite understanding what Abby is asking.As the friendship between Owen and Abby deepens, Father starts feeling jealous. He tries again to obtain blood for Abby. This time he chooses to hide in the back seat of a student's car and attack him on the road. His plan is foiled, however, when Jett's friend Greg asks for a lift. When Jett stops for gas, Father attacks Greg and drives off. The struggling boy causes them to go over an embankment and turn upside down, pinning Father under the car and killing Greg. Knowing that he is trapped and about to be discovered by the police, Father pours acid on his face so that he can't be identified. When Abby learns that he has been taken to a hospital, she shows up at the reception desk asking for her father. The receptionist tells her that he is on the 10th floor, so she climbs/flies up the outside of the building until she gets to his window. Father lets her in and offers her his neck. After Abby drinks his blood, he jumps out of the window and falls to his death. At the nurse's station outside Father's room, the Detective taking a call from the receptionist in the lobby hears the nurse scream. By the time the detective gets to Father's room, he has jumped out of his tenth floor window to his death, leaving only a note that reads: "I'm sory Abby".Abby returns to the apartment building and taps on Owen's bedroom window, asking to be let in. Owen is almost asleep but he tells her to come in. Abby removes her bloody clothes and crawls into bed with him. Owen asks her whether she'd like to go steady with him, and Abby replies "I'm not a girl." That doesn't seem to bother Owen, so they decide to go steady. The next morning, Abby returns to her own apartment, but she leaves a note for Owen that reads, I must be gone and live or stay and die .One afternoon on a school outing to a local pond for some ice skating, Kenny, Mark, and Donald again confront Owen with a warning that they are going to push him into an ice hole. This time, however, Owen stands up for himself and takes a swipe at Kenny's head with a big stick, causing his ear to bleed. At the same time, some other students have noticed a body frozen in the ice. The police are called, and the body is cut free.Later that afternoon, after school is out, Owen brings Abby to a secret room in the basement of the apartment building. When Abby asks why they're there, Owen pulls out a knife and cuts his finger, offering to mix bloods with her. Watching Owen's blood drip on the floor, Abby can no longer stand the hunger that she's experiencing now that Father is no longer providing her with blood. She falls to the floor and begins to lap up Owen's blood. She finally transforms into her true vampire image with white cataract eyes, unappealing facial warts, and sharp teeth. Abby hisses at Owen to go away; when he doesn't, she runs off herself. Overcome with bloodlust, Abby jumps on the next person who walks by... Virginia (Sasha Barrese). Fortunately, Virginia's boyfriend Larry (Dylan Kenin) is able to kick Abby off before she kills Virginia. Unfortunately for Virginia, Larry's save only means that Virginia is doomed to become a vampire herself. She notices the change the next morning, after being transfused with six pints of blood. She wakes up, starts to drink her own blood from her arm, and bursts into flames when the nurse opens the curtains.A wimp he might be, but Owen is not a dummy. He has figured out that Abby is a vampire and confronts her at her apartment that evening. When he asks her if she is a vampire, she does not seem to understand the word and she only replies: "I need blood to live". He asks her how old she really is. Like before, she admits to being 12 but says that she's been 12 for a long time. He asks the whereabouts of her dad, and she says that he wasn't really her father. Owen finds an old photo of Abby and Father, taken when Father was about 12 years old. Abby looks just the same as she does now. Concerned about what she might do to him, Owen goes home. Later, as he's about to sit down to the pot pie left for him by his mother, Abby knocks on the door. She requests to be invited in, but Owen stalls. He asks her what would happen if he didn't invite her. Silently, Abby walks in uninvited. Almost immediately, her skin begins to bleed. Owen quickly invites her in and gives her a hug. After showering, Abby changes into one of his mother's old dresses. When Owen's mom unexpectedly comes home, Abby immediately scampers across the window from Owen's apartment to hers, even though it's two stories up.The next morning, Owen finds a note from Abby asking him whether he would like to hang out with her that evening. Meanwhile, based on Larry's description of Virginia's attacker, the Detective has traced Abby to her apartment. He breaks in and finds her asleep in the bathtub. Because he can't see in the dark, he rips open the foil covering the windows. Immediately, Abby's skin begins to crack when it is exposed to the sunlight. Owen, who was in the apartment waiting for Abby to wake up, screams "NO!" giving Abby sufficient time to jump on the Detective and drink his blood. As he lays dying, the Detective reaches out to Owen for help, but Owen closes the bathroom door and leaves him to his fate. After feeding, Abby informs him that she must go away before the rest of the police show up looking for the detective. That night, Owen looks out the window to see Abby getting into a taxi to move away.After Abby is gone, Owen returns to his normal boring routine of going to school and going home. One evening, he is about to start swimming lessons with Mr. Zoric (Ritchie Coster). As he gets into his swimsuit and begins his lesson, Kenny, Mark, and Donald start a fire in the dumpster behind the gym, forcing Mr. Zoric to leave the pool area unattended. When Mr. Zoric goes to put out the fire, they lock him out of the gym and go back into the pool where Kenny's older brother Jimmy (Brett DelBuono) has kicked everyone out of the pool and made Owen get back in. Jimmy gives Owen an ultimatum: either stay under water for three minutes or have one of his eyes poked out... Owen's eye for Kenny's ear. Then Jimmy pushes Owen under. A minute passes. Suddenly, pandemonium breaks out in the gym. From his underwater point of view, Owen hears bullies screaming, then Jimmy's severed head falls into the water, followed by more body parts. An almost drowned Owen surfaces and crawls out of the water. He looks up to see Abby's bloody feet standing beside him. She had apparently crashed into the pool area through a skylight window and in a matter of seconds bit, torn, beheaded, dismembered and disemboweled all four bullies to save Owen.Epilogue. Owen sits on a train traveling towards an unknown destination. Snow is falling outside. A large trunk sits in front of him. From inside the basket comes a rapping. Owen raps back in Morse Code and then takes a bite from a Now & Later. It is clear at this point that Owen has become Abby's new protector and handler, and they are traveling to find a new life for themselves.