Some time ago in the fairy-tale world it was decided that children of negative characters should not be responsible for their parents. After all, each of them has something good that can bring great benefit to ordinary people. Jay (Booboo Stewart), son of the omnipotent magician Jaffar, Carlos (Cameron Boyce), whose mother is the famous criminal Cruella de Ville, daughter of the Evil Queen Ivi and Mel, who gave birth to the black witch Malifiscent. To such children it was easier they go to the same school with sons and daughters of positive characters. Of course this is an extremely unusual educational institution, because most of the students already have unique abilities.
As described in the film "Descendants 2 (2017)", all the anti-heroes of the fairy kingdom are on an isolated Lost Island. Mel comes here on vacation. The girl is accompanied by Ben (Mitchell Hope), who is in love with her, the son of the Beauty and the Beast. In order to stay on the island, the guy needs to learn some villainous manners and habits. Only no one knew that a real conspiracy was brewing here. All sorts of anti-heroes have developed a plan, according to which they can break free.