After the wedding of Belle and the Beast, they establish the United States of Auradon from the surrounding kingdoms, creating a prosperous new nation, and are elected King and Queen. The kingdom's villains are imprisoned on the Isle of the Lost, a slum where magic is suspended and surrounded by a barrier. Twenty years later, Prince Ben is to ascend the Auradon throne and informs his parents that his first proclamation is give the Isle of the Lost's children the chance to live in Auradon, away from the influence of their villainous parents. The first four children he has chosen are Carlos, son of Cruella de Vil; Jay, son of Jafar; Evie, daughter of Evil Queen; and Mal, daughter of Maleficent. On the island, Maleficent instructs the four chosen children to use the opportunity and steal the Fairy Godmother's magic wand to release the villains.
Traveling to Auradon Prep, the four meet Ben and his self-proclaimed girlfriend Audrey, daughter of Princess Aurora. They also meet the Fairy Godmother who is the school's headmistress. Evie uses her mother's pocket-sized magic mirror to locate the wand that's in a nearby museum, and Mal uses her mother's spinning wheel (an artifact in the museum) to put the guard to sleep, but they fail to steal it. Learning the Fairy Godmother will use the wand at Ben's coronation, the four wait it out by attending classes but start to fit in with the students. Jay is recruited into the school's "tourney" team (a hockey-like sport), while Carlos surpasses his cynophobia by befriending the school's mutt Dude. Evie, though intelligent, acts vain to impress Chad, son of Cinderella, but ends up doing his homework for him. Dopey's son Doug encourages her to not pander to others and be herself.
Mal becomes popular, using Maleficent's spell book to improve the looks of Jane, daughter of Fairy Godmother, and Lonnie, daughter of Mulan. Learning also Ben's girlfriend will be seated close to the wand during the coronation, Mal bakes a cookie laced with a love potion and gives it to Ben, who falls madly in love with her, much to the shock of his friends. On a date with Ben, Mal becomes conflicted with her inner goodness and desire to please her mother, unsure how to react to Ben's feelings towards her. During the school's family day, the villains' children are ostracized after an encounter with Audrey's grandmother Queen Leah. Though Ben, Lonnie and Doug remain friendly towards them, they are forced to distance themselves from the quartet.
On the day of the coronation, Mal gives Ben a brownie containing the love spell's antidote, believing it is unnecessary to keep Ben under the spell, but he reveals he was already freed of the spell since their date when he went swimming in the Enchanted Lake and believing that Mal only did it because she really liked him. During Ben's crowning, a disillusioned Jane grabs the wand from her mother, accidentally destroying the Isle's barrier. Mal takes the wand from Jane, but torn over what to do, is encouraged by Ben to make her own choice rather than follow Maleficent's path. Mal recognizes that she and her friends found happiness in Auradon, and they decide to be good.
Maleficent crashes the ceremony, freezing everyone in time except herself and the four children. When they defy her, Maleficent transforms into a dragon. Together with Mal use a counter spell turning Maleficent into a tiny lizard based on the amount of love in her heart. Mal returns the Fairy Godmother her wand and tells her not to be hard on Jane. The Fairy Godmother then unfreezes everyone. While the villains watch the celebration from afar, Auradon Prep's students party through the night, with Mal and her friends finding happiness.
Output: What happens when Mal bakes a cookie and gives it to Ben?