When the pressure to be royally perfect becomes too much for Mal, she flees Auradon only to have Evie and the rest of the gang sneak onto the Isle to retrieve her. But there's a new, self-proclaimed queen of evil in town: Mal's archenemy Uma, daughter of Ursula. Together with her pirate crew, including Captain Hook's son Harry and Gaston's son Gil, Uma unleashes havoc on Auradon!

The VKs return to the Isle of the Lost to recruit a new batch of villainous offspring to join them at Auradon Prep. When a barrier breach jeopardizes the safety of Auradon during their departure off the Isle, Mal resolves to permanently close the barrier, fearing that nemeses Uma and Hades will wreak vengeance on the kingdom. Despite her decision, an unfathomable dark force threatens the people of Auradon, and it is up to Mal and the VKs to save everyone...