After staying up late at his lab, Dexter oversleeps, waking up one minute before his school bus arrives. With no time to do his morning chores and homework, he pulls out a secret prototype device, which converts his last 30 seconds into 30 minutes.
When an electrician comes to Dexter’s house to repair a blown-out fuse, he accidentally stumbles onto his laboratory, and Dexter enlists him to repair the lab.
Dexter’s family goes to the beach, where Dexter tries to communicate with whales. He must rescue Dee Dee (dressed as a mermaid), when she is captured by manic pirates.
Suspicious that Dee Dee has not entered his lab even once on a particular day, Dexter shrinks himself and enters her room to spy on her. He soon becomes an unwilling character in Dee Dee’s doll story, but he believes the story to be real.
When Dexter is asked to bring his mother to school, he disguises Dee Dee as her so that she can take her place, but Dee Dee does not behave like their mother.
Dexter accidentally gives himself telepathy that he cannot shut off when trying to overhear his father’s thoughts to figure out what he got for his birthday, causing everyone to accidentally read his own mind.
Dexter thinks that a crazy homeless person balancing electronic devices on his head and muttering gibberish is a genius trying to contact aliens, so he takes him home.
Dexter reluctantly takes piano lessons from Professor Williams (Paul Williams), but when the Professor stumbles onto Dexter’s lab, he discovers that Dexter has more musical talent than he thought.
Dexter and Mandark bring the Abraham Lincoln and George Washington faces respectively on Mount Rushmore to life and make them fight each other to determine who is the best.
Dexter and Dee Dee’s father buys a video game for them to play, but the game sucks Dexter inside when he plugs in the cartridge, and it is up to Dee Dee to bring him out.
Created and narrated by a six-and-a-half-year-old boy named Tyler Samuel Lee, who sent a tape containing the episode’s audio to Cartoon Network,[9] the story follows Dexter and Mandark’s robot “brother” Computress teaming up to make Mandark’s head shrink.
In need of an assistant to operate his latest invention, Dexter performs a brain transplant on Dee Dee to make her smart enough to fulfill the role. With her new brain, Dee Dee proves to be more intelligent than Dexter.