When the music hating Blue Meanies take over Pepperland and freeze everyone within it, including the protectors, Sgt Peppers Lonely Hearts Club Band. Captain Fred and his Yellow Submarine recruit The Beatles to help save Pepperland. Along the way, they fall through the Sea of Time, Sea of Nothing, Sea of Holes and more. They meet Jeremy Hillary Boob PhD. and take him with them along the adventure. When at Pepperland, the Beatles "rally the land to rebellion" and take down the Blue Meanies, the four-headed Meanie dog and the Dreadful Flying Glove (with the songs "Sgt. Peppers Lonely Hearts Club Band", "With A Little Help From My Friends", "Hey Bulldog", "All You Need is Love"). In the end, we see all four live-action Beatles singing "All Together Now".
Protagonist Alex DeLarge is an "ultraviolent" youth in futuristic Britain. As with all luck, his eventually runs out and he's arrested and convicted of murder and rape. While in prison, Alex learns of an experimental program in which convicts are programmed to detest violence. If he goes through the program, his sentence will be reduced and he will be back on the streets sooner than expected. But Alex's ordeals are far from over once he hits the mean streets of Britain that he had a hand in creating.