Coraline Jones, a girl with an explorer's spirit but often neglected by her busy, work-from-home parents, finds herself in a new, old house that feels too quiet, too dull. Her only companions are the eccentric residents of the other flats: the aging actresses Miss Spink and Miss Forcible, with their multitude of Scottish terriers, and the peculiar Mr. Bobo, who claims to be training a mouse circus upstairs. Coraline longs for adventure, for something more than the bland meals and distracted murmurs of her mother and father.
One rainy afternoon, her curiosity leads her to a mysterious, locked door in the drawing-room. Her mother opens it to reveal only a brick wall, sealing off an empty flat beyond. Yet, Coraline feels a peculiar pull, a sense that something more lies hidden. Later, the door creaks open on its own, revealing not a brick wall, but a dark, inviting passageway. Unable to resist, Coraline crawls through, emerging into a flat uncannily similar to her own, yet subtly, disturbingly different.
Here, she meets her "Other Mother" and "Other Father." They possess button eyes, a detail that is unsettling but initially overshadowed by their attentive smiles and the delicious food they offer. This other world is a vibrant, exciting place, a fantastical mirror of her own, where her "other" parents shower her with the attention and delights her real parents often overlook. The Other Miss Spink and Miss Forcible are youthful, performing an endless, dazzling circus act for an audience of enthusiastic terriers. Mr. Bobo's mice perform magnificent feats. It seems a perfect dream, a world crafted just for her.
But the enchantment begins to fray. The Other Mother offers Coraline a chance to stay forever, but only if she allows buttons to be sewn over her eyes, just like everyone else in this world. Horrified, Coraline refuses, a brave defiance that reveals the sinister nature beneath the other world's charming facade. She flees back through the door, only to discover that her real parents are gone, kidnapped by the Other Mother. The house is silent, chillingly empty.
Gathering her courage, a quality she learns she possesses more than she knew, Coraline returns to the other world, determined to rescue her parents. She finds an ally in a cynical black cat, who can speak in this strange realm and offers cryptic, yet vital, advice. The cat explains that the Other Mother, whom he calls the "beldam," thrives on stealing children's souls, trapping them in her world. Coraline soon encounters the ghostly apparitions of three children, previous victims of the beldam, imprisoned behind a mirror. They warn her of their fate and implore her to find their lost souls.
Coraline challenges the Other Mother to a game: if Coraline can find her parents and the souls of the three ghost children, they will all be set free. If she fails, she will stay forever and have buttons sewn over her eyes. With a magical looking-stone given to her by the real Miss Spink and Miss Forcible, Coraline navigates the increasingly twisted and dangerous other world. The Other Mother's creations become grotesque and menacing; the Other Father is a mournful, dough-like creature, the Other Miss Spink and Miss Forcible are fused into a monstrous, waxy being, and Mr. Bobo's mice are revealed to be rats, the beldam's spies.
Through wit, bravery, and a growing understanding of the Other Mother's manipulative nature, Coraline locates the marble-like souls of the ghost children, hidden in plain sight within the corrupted forms of the other world. She discovers her parents trapped within a snow globe, a final, chilling revelation of the beldam's cruelty. In a climactic confrontation, Coraline tricks the Other Mother, using the black cat as a diversion and seizing the snow globe. She makes a desperate escape back to her real world, slamming the door on the beldam's reaching hand, severing it.
Back in her own home, her parents return, oblivious to their ordeal. Yet, Coraline knows the danger isn't truly over. The beldam's severed hand, still hungry for the key to the other world, stalks her. Coraline devises a final, clever plan. She lures the hand to an old well, using the key as bait, and tricks it into falling into the depths, sealing the threat once and for all. Coraline has faced her fears, saved her family, and learned to appreciate the imperfect, yet genuine, reality of her own life.