|Season 3, Episode 30|
|Airdate:||Jul 09, 2004|
|Writer(s):|| Mo Willems|
|Storyboards by:|| Guy Moore|
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Figure Out Unusual Nerd's Tantalizing And Impossible Necessity
Summary: One of the girls' bathrooms at Gallagher Elementary hides a secret: a fountain of eternal youth. The DCFDTL have taken the interest of destroying it. Now Numbuh 1 and his team must save Leaky Leona and stop the Delightful Children from destroying the fountain.
- Villains : DCFDTL
- Ally: Leaky Leona
- Cameos: Lunk (delightfulized)
- Locations: Gallagher Elementary School, Ancient School
- Villain Technology:
- Really Really Incredibly Destructive Machine
- Fountain Water Squirt Gun
- When Sector V was changing back to their older forms, it is clear that Nigel's hair color was brown.
- This episode explains why Abigail hates the DCFDTL. She lashes out in anger a couple of times, and there's an explanation to why she refuses to be leader of Sector V.
- Kuki was the closest to being destroyed by Leona, as she was shot with the water cannon three times versus everyone else, who were shot up to only twice.
- During the first scene in the girls' bathroom, the stripe on Lenny's football helmet is red instead of white.
- This is the second time Lenny's face is shown.
- At the beginning of the episode, when Sector V are all in the girls bathroom, Numbuh 2 finally told a decent joke to Wallabee about Leaky Leona.
It is revealed in this episode that the Delightful Children were responsible for Nigel Uno's permanent baldness
The statue of the Librarian in the ancient Library bears a striking resemblance to Madam Margaret (in her robotic form).
- This episode bears a slight similarity to Harry Potter and the Chamber of Secrets, in that there is a series of chambers buried beneath the school only accessible through a girl's locker room.
- Despite the Delightful Children once being Sector Z they stayed the same even though they became younger then they had been when they were transformed.
- This episode is based on the story of the Fountain of Youth, turning it into a water fountain. It also presents the subterranean "other school" into a parody of an ancient temple, with several of the main parts of the school system - i.e. library, lunchroom, and gym - being used as models for the various chambers that heroes have to pass through in archaeology-based movies that are designed to test their worthiness.