Judith Hoag

Marnie, Dylan, and Sophie Piper have their first out of many adventures! On Halloween, while Marnie is arguing with her mother Gwen, the kids' grandmother Aggie comes to visit. Aggie wants to start Marnie's witch training before her 13th birthday or Marnie will lose her powers forever. But there is another reason for Aggie's visit. Something dark & evil is growing in Halloweentown & Aggie wants help to defeat it. While Aggie & Gwen are arguing, Aggie uses magic which Marnie observes. After Aggie leaves to return to Halloweentown, Marnie, Dylan and, unknown to Marnie and Dylan, Sophie follow her onto the return bus. Soon afterwards, Gwen follows the children to Halloweentown. While there, Aggie & Gwen are attacked by the dark force in a movie theater. Marnie, Dylan & Sophie race to get the ingredients to activate Merlin's Wand to stop the evil.

The Cromwell clan live in the real world, except for their grandmother who lives in Halloweentown, a place where monsters go to escape reality. But now the son of the Cromwells' old enemy Kalabar has a plan to use the grandmother's book to turn Halloweentown into a grey dreary version of the real world, while transforming the denizens of the real world into monsters. Only Marnie, a fledgling witch, can thwart the evil scheme.

Marnie and Dylan have graduated high school and are now going to go to college at Witch U in Halloweentown. Marnie is offered a full scholarship, Marni's mother, Gwen of course does not want her daughter at school in Halloweentown so she forces Dylan to tag along. At the school, witches and warlocks can't use magic. Marnie soon makes a new friend named Aneesa, whom is a genie. Marnie soon discovers that she is partly to blame for the rules against the use of magic at school. At one point a box, with the name "S. Cromwell" inscribed on it, magically appears in front of her. Most people at the school believe that Marnie used her magic to conjure up the box, but it was brought to her by fate.