Jimmy Neutron is the smartest kid in town. As a genius, Jimmy thinks most things can be solved with the invention of a new gizmo. But Jimmy usually takes the easy way out, and his backfiring gadgets result in comedic adventures.

The Yolkians have come to earth, but this time they seek out only peace and brotherhood with the people of Retroville. While Jimmy Neutron suspects the worst, everyone in town is ready to forgive and forget. This special serves as a direct sequel to the Jimmy Neutron movie.