When the pressure to be royally perfect becomes too much for Mal, she returns to the Isle of the Lost, where Uma, the daughter of Ursula, has proclaimed herself queen. Still resentful over not being selected to go to Auradon Prep with the other VKs, Uma and her pirate gang plot to break the barrier between the Isle and Auradon, and unleash all of the villains imprisoned on the Isle, once and for all.