“Monster High: Ghouls Rule” delves into a long-standing feud between humans, known as “Normies,” and monsters, setting the stage for some frightening developments. Traditionally, Monster High students were advised to remain indoors on Halloween to steer clear of any trouble. However, Frankie and her friends uncover a forgotten past where ghouls and “Normies” joyfully celebrated the holiday together. Determined to revive this tradition, the ghouls aim to embrace the night as an opportunity to express their uniqueness and demonstrate that it’s perfectly fine to “Be Yourself. Be Unique. Be a Monster!”