Bubbles accidentally activates her 'Devolutionizer' device (age-reversing machine) just as it topples over, affecting the entirety of Oddsville . All the Oddbods devolve into Babybods; that is, all except Fuse, who's returning home from a fishing trip. It's time for Fuse to 'Nanny-up', keep his temper in check, and figure out a way of undoing the whole process.