In an exciting journey through time and music, two best friends, Bill and Ted, find themselves at a crucial moment in their lives. Years after having traveled through time in their adolescence and after a historic time-traveling adventure, they have grown into adults who have not achieved the musical success they had hoped for. Their dreams of forming a legendary band that unites the world seem further away than ever. One day, they receive a surprising visit from a futuristic version of themselves, who reveal that the universe is about to collapse due to the lack of a great song that they need to write.
Determined to save the future and their legacy, Bill and Ted embark on a new time-traveling journey, which takes them to different eras and realities. Along the way, they encounter iconic characters, unlikely allies, and a series of wild antics that only they could experience. But they are not the only ones on this quest; their daughters, who have grown tired of their fathers' lack of ambition, decide to seize the opportunity to compose their own epic song.
This installment is filled with absurd humor, heartwarming moments of friendship, and the eternal struggle to find purpose in life. As Bill and Ted try to discover the melody that will save the world, they also learn that true greatness is not measured only by success, but by the love and support of those around us.