After recovering the latest ghost mask, Jackie returns to Section 13 to find Jade excitedly organizing props, a costume she feels is sure to win the “Scariest Costume” award at her school's spooky Halloween party that night.Hoping to compete with her for the honor is Parker, who will be there with the heroic Cow Warriors to spend the festival with their friends.When Parker stumbles upon his new Oni mask, he realizes that the mask is undoubtedly terrifying and might be what he needs to stand a chance at winning the Masquerade Competition.So Parker accidentally puts it on and undergoes a magical transformation to become our newest demon!Now, Brother Long and Warrior Ox must come to save Parker, who is determined to show his most terrifying look!