30 years after John, Paul, George, and Ringo turned the Blue Meanies good, it is now 1998...
Julian Lennon, James McCartney, Dhani Harrison, and Zak Starr/Starkey are staying together in 'The Pier,' and life is moving along lazily. But then Old Fred's niece Fern arrives in the Yellow Submarine, and says that a big threat- bigger than the Blue Meanies- has arrived to Pepperland, and it's here to stay.
But The Beatles have disbanded. John is dead, George's health is declining, and Paul and Ringo are busy with their own careers. So, the Sons of the Fab Four must now go on a musical and slightly comedic, if not dramatic, adventure to save Pepperland, and perhaps run into some old friends.