At the Echo Creek graduation party, Marco struggles to reconnect with Star after the events of Face the Music. While Queen Moon invades Ludo's new castle with the Magic High Commission, Star is convinced by her friends to ditch the graduation party and instead attend a party with Oskar. Meanwhile, Toffee takes possession of Ludo's body and regrows his severed arm from Ludo's wand, draining the magic of the Magic High Commission and nearly killing Queen Moon. When Star returns, Queen Moon informs her that they will have to leave Earth. Star confesses to Marco about her feelings for him and tearfully leaves him forever.
After having skirmished with a number of dangerous monsters, Star Butterfly arrives on Earth to live with the Diaz family. However, rather than living a normal life, Star continues on having to battle villains both throughout the universe and in their high school, although if only to protect her extremely powerful wand, an object which she is still confused with.