Marnie and her kids get a big shock when they follow grandma home to Halloweentown – and find out they come from a family of witches. The town is the only place where supernatural beings can lead a `normal’ life, but trouble is looming, and on her 13th birthday Marnie not only finds she is a witch, but that she and her family are involved in a fight against the evil that is threatening to take over the world.