Coraline Jones is a bored girl living in a new house with her overworked parents and eccentric neighbors. One day, she discovers a door to another house, with her Other Mother, and Other Father living there. The house is exactly the same, except better in every way, with good meals, entertaining shows put on by the neighbors, and an amazing garden. The only difference is that everyone has buttons where their eyes should be. Other Mother wants Coraline to live with them forever, but to do so, Coraline would need to have buttons sewn onto her eyes. When Coraline refuses, the Other Mother throws her into a mirror, where she meets the ghosts of three children. The children warn her that the Other Mother is a Beldam who wants to steal Coraline's soul. Coraline escapes.
When she gets back to her regular world, Coraline discovers that her parents have been kidnapped by the Beldam. She returns to the Other House, along with the Black Cat (Who can speak in the other realm) to rescue her parents and the souls of the dead children. In order to get them, she challenges the Beldam to a finding game. The Beldam hides the three souls around the house, with the other occupants trying to stop Coraline from winning. Coraline succeeds in getting all three souls and rescuing her parents who were trapped in the snowglobe on the mantlepiece. With the Cat, she escapes back into the real world,where her mother and father greet her (with no memory of being trapped in the Other House).
BUT....The Other Mother's spidey arm makes it into the real world, and comes after Coraline, who has the key to the magic door. It chases her to an abandoned well. Coraline, with the help of her friend Wybie, break the hand, and tie it up with a rock pinning it down inside a bag. The bag is thrown in the well with the key, so no one will ever find them.
The movie ends with a picnic attended by the resident's of the house, and Wybie's grandmother, whose sister was one of the dead children captured by the Beldam.
Thanks Paul B!