When his fairy godparents, Cosmo and Wanda, fulfill this wish, Timmy is sent to the town of Retroville in the universe of child prodigy Jimmy Neutron.

In an attempt to gain Cindy's affections, the two engage in a battle of smarts that sends Jimmy and his friends to Dimmsdale.

As Jimmy seeks to prove that Timmy is a fraudulent scientist, Cosmo and Wanda struggle to keep their existence a secret from the people of Retroville.

Meanwhile, Professor Calamitous, a major villain in Jimmy's universe, unleashes a surge of anti-fairies from Fairy World that threatens the rotation of Timmy's Earth.

[2] In their third and final encounter, Jimmy and Timmy make amends while trying to defeat the enemies from their own universes—including a monster that they concoct together—while purposefully rejecting their respective friends in the process, including Cindy.

Initially, they are unable to make the monster evil enough to fight them properly, but when they succeed, he almost immediately turns against them and absorbs Cosmo and Wanda's magic and Jimmy's intelligence, and then begins destroying both children's universes.

[5] Terry Kelleher of People gave the first special three stars out of four, calling it a "blast of creativity" although hard to follow.

He also praised the "funny gags" for "[Timmy and Jimmy] poke fun at each other's setting and basically have a good time.