Neil Gaiman’s children’s novel Coraline begins when Coraline, a young girl, and her parents move into a second-floor flat in an old house. In the opening pages, Coraline explores her new home and meets her rather eccentric neighbors. On the third floor lives a “crazy old man” named Mr. Bobo who claims to be training a mouse circus, although he will not let Coraline see it. Miss Spink and Miss Forcible, elderly ladies who are former actresses and keep a clan of Highland terriers, live on the first floor. They warn Coraline not to go near the well by the house, and they also give her a stone with a hole in it for protection. In addition to her neighbors, Coraline notices a black cat that follows her around outside the house, although he runs away whenever Coraline approaches.

Inside her own apartment, Coraline finds a locked door at the far corner of the drawing room. Her mother unlocks it and reveals that the door opens onto a brick wall—on the other side, she explains, is another empty apartment.

In the days that follow, Coraline becomes bored, left to her own devices in the apartment, waiting for school to start. When she complains to her parents, they brush her off, telling her to amuse herself so that they can concentrate on their work.

One day, when Coraline’s parents are out, Coraline takes the house keys and opens the locked door again. This time, she finds not a brick wall, but a dark hallway on the other side. She walks down the hallway and realizes she is in a flat that looks almost exactly like her own, except for small details such as the changed expression of a boy’s face in a painting on a wall. Coraline hears a voice that sounds like her mother’s call her name and follows the voice to a kitchen. She finds a woman who looks a bit like her mother, but with white skin, long, sharp fingernails, and black buttons for eyes. When Coraline asks the woman who she is, she says she is Coraline’s “other mother.” Coraline’s “other father,” who also has black button eyes, joins the two, and they have a delicious lunch. Coraline’s “other” parents tell her they have been waiting for her for a long time.

After lunch, Coraline goes to inspect her “other” bedroom, where she finds a number of unusual toys and fifty rats under her bed. The rats belong to the “other” strange man upstairs, who soon comes to collect them; he invites Coraline upstairs, but she feels uneasy and refuses.Instead, she wanders outside and finds that the house and garden look almost the same as they do outside her home, although Miss Spink and Miss Forcible’s apartment is surrounded by flashing lights. Next, Coraline sees a black cat just like the one outside her real home, although now the cat speaks to her in a human voice. The cat says he is not the “other” cat because unlike people, cats “keep ourselves together.”

After the cat disappears, Coraline wanders into Miss Spink and Miss Forcible’s flat, which has become a theater where the two women transform into young, glamorous versions of themselves and perform for an audience of terriers.

When Coraline returns to her “other” flat, her other parents tell her she can stay forever—if she agrees to wear button eyes. Coraline, horrified, runs back down the hallway to her own flat, and once she arrives, the brick wall reappears behind her.

However, that night, Coraline’s parents do not return home, and they do not come back the next day either. Finally, the black cat appears inside the flat and leads Coraline to a mirror at the end of the hallway. Coraline sees her parents reflected in the mirror, and her mother breathes on the glass and writes “HELP US” in the fog before their image fades away.Coraline calls the police, who do not take her seriously; then, sure that her other mother has her real parents, Coraline goes back through the locked door, down the dark hallway to the other flat.

Coraline’s other parents act overjoyed to have her back, but when Coraline accuses them of stealing her real parents, her other mother becomes angry and cold. She locks the door between the two flats, keeps the key in her pocket, and then tells Coraline to go to bed.

The next morning, Coraline begins looking for her parents and for a way out. She finds the cat—who now talks again—and he advises her to “challenge” the other mother to a game. As Coraline continues to explore, she notices a snow globe with two people inside, which is not in her real flat. Next, Coraline tries to walk beyond the other garden, but she finds herself lost in a gray mist, and eventually ends up back in front of the other house. She realizes she is trapped.

Later that day, Coraline is rude to her other mother, and the other mother locks her in a dark space hidden behind the hallway mirror.Coraline discovers three ghost-children in the darkness. They tell her that the other mother has taken their souls, and that is why they are trapped here even after their deaths. They add that if Coraline can save her mother and father, she might also be able to free the children’s souls.

When the other mother lets Coraline out, Coraline proposes a game. If she can find her parents and the souls of the children behind the mirror, the other mother will have to free them all—Coraline, her parents, and the dead children. If Coraline cannot find them, she will stay with the other mother forever. The other mother agrees and swears on her right hand to keep her word.

Coraline begins to search her other bedroom, and she remembers a voice in her dreams that told her to “look through the stone.” She still has the stone with the hole in it Miss Spink gave her, and when she looks through it, the world becomes colorless—except for a red spark.She grabs the spark and finds that it is a marble; then she hears the voice of one of the dead children, confirming that she has discovered his soul.

Coraline finds the second marble in the other Miss Spink and Miss Forcible’s flat; the theater now appears lifeless, and the two women have morphed together into a kind of creature encased in a sac against a wall. The marble is curled in one of their hands. After Coraline takes it, the creature reaches for her but cannot leave the wall, and Coraline runs out.

Outside, Coraline’s other mother gives her a key to the empty flat, and despite the cat’s warning that this must be a trick, Coraline goes in. In the empty bedroom, she finds a trapdoor and heads down it into a basement. There, she finds her other father, horribly disfigured; Coraline realizes the other father is just a thing the other mother made and threw away. The other father tries to attack her, and Coraline makes it out of the basement and closes the trapdoor just in time.

Next, Coraline goes to the third floor, occupied by the other old man and the rats, and sees the third marble glowing from the old man’s raincoat.The man suddenly falls apart, and rats scurry out of his clothing, one of them carrying the marble. Coraline races after the rat, but it evades her grasp; however, the cat catches it and brings it to her, along with the marble. Coraline then remembers the snow globe and realizes that is where her parents are; however, she suspects her other mother does not plan to let her go, so Coraline decides to trick her.

Holding the cat, Coraline tells the other mother she thinks her parents are in the passageway between the houses. While the other mother is unlocking the door between the houses, Coraline takes the opportunity to grab the snow globe and throw the cat on the other mother. He promptly attacks her, and Coraline runs for the open door, calling for the cat to follow her. With a great struggle, Coraline manages to close the door behind her, and she and the cat run through the dark hallway.Finally, Coraline makes it back to her own home and instantly falls asleep.

Coraline awakens to find her real mother shaking her; her parents are safe and appear unaware of what happened. In Coraline’s pocket are the marbles, the stone, the now empty snow globe, and the key to the empty flat her other mother gave her. Coraline threads the key on a string and wears it around her neck. That night, she dreams of the three dead children; they thank her for freeing their souls but warn her that her own troubles might not be over yet.

The next morning, Coraline is awoken by a scrabbling noise. She sees a horrible thing running and realizes it is her other mother’s hand, and it wants the key back. Coraline lays a trap in the garden by secretly removing the boards over the well and replacing them with a tablecloth.She places the key in the middle of the tablecloth, and the hand jumps for the key and knocks the tablecloth into the well. The hand falls in, and Coraline replaces the boards over the well, ensuring the hand can never get out. Satisfied the other mother is vanquished, Coraline prepares for her new year at school, finding that the thought of returning to school can no longer scare her the way it once did.