Our story starts out when a young lady named Coraline Jones moves into an apartment in an old house with her parents. Her neighbors include two elderly retired actresses and a strange man who lives upstairs and trains mice for a circus act. Despite this weirdness, Coraline is very bored. Her parents work a lot and they tend to just ignore her.
One day, Coraline discovers a door with a brick wall behind it. Seems kind of strange, right? But get this: when she opens the door later, there's a hallway back there. Now that's strange. When Coraline goes through the door, she ends up in an entirely different world: it's kind of like her own, but something's a little off. In the other world, Coraline has an other mother (the beldam), an other father, and other neighbors. And bonus, cats can talk.
Coraline decides this other world is weird (we agree) and so she heads back home. But when she arrives, her parents are missing: the beldam has kidnapped them, and Coraline will have to go back into the creepy other world to rescue them. Fast forward a bit: and, spoiler alert, she succeeds! She gets her parents back and, in the meantime, also rescues the trapped souls of three kidnapped children who have been stuck in the other world for a long time. Coraline beats the evil beldam, saves the day, and returns home.
But wait: it's not quite over. It turns out the other mother's hand has followed Coraline home (it's like Thing on the Addams Family!). Coraline plays one last trick to trap the other mother's hand in a deep well. Phew, finally the scariness is over. After all this excitement, Coraline is ready to start the school year; and boy, is school going to seem really tame by comparison.