A video of Rocky and Bullwinkle playing a song goes viral and they're rocketed to musical superstardom. They decide to use their newfound celebrity to launch a "save the birdbath" concert tour to restore the giant birdbath they destroyed.

Rocky, Bullwinkle, Boris and Natasha are kidnapped by a super-fan named Francis, the eight-year-old heir to the Puffy Platypus Pizza franchise, to play a private concert for his birthday.

Rocky and Bullwinkle return to Frostbite Falls to discover that because they failed to rebuild the giant birdbath, their beloved town is now completely overrun with dirty, zombie-like birds.