During a trip to his grandfather’s house, Dexter learns that the outwardly boring old man has a lab just like his own.

When his family is suffering from the flu, Dexter tries his best to not acquire the illness, but his efforts are thwarted by a sick Dee Dee’s presence in his lab.

Dexter’s new device allows him to study for the next day’s French test while sleeping. It malfunctions, causing a single phrase (omelette du fromage) to repeat throughout the night, causing Dexter to wake up the next morning speaking nothing else except omelette du fromage.

Dee Dee wins a golden diskette, earning her a free trip to the laboratory of Professor Hawk (Tom Kenny), one of Dexter’s favorite scientists.

Dexter creates a magnetic field to keep Dee Dee away from him, but it malfunctions, causing them to stick together.

Dexter and Mandark team up to fight asteroids that are heading towards the Earth.