Sequel to the 1998 television movie "Halloweentown." Grandmother Aggie sweeps granddaughter Marnie and Sophie off to Halloweentown to investigate a series of strange occurrences. When they arrive, the vibrant community seems to have lost its magic. The citizens, including the gargoyles, are gray and boring. It isn't long before Aggie discovers that her spell book is stolen and the trio decides to set out and find it. They discover that an angry warlock -- Kal, Kalabar's warlock son, who is seeking to avenge his father's death -- has taken the book and plans to turn every human into whatever costume they are wearing at midnight on Halloween. When Grandma Aggie also falls victim to the wicked spell, it's a race against time, as Marnie must use her skills to defeat the young warlock threatening to change Halloweentown for eternity.