While Homer takes the Duff Blimp for a joyride, Lisa discovers a secret room in the basement of Sprinfield Elementary School.



(created by), (developed by) | 3 more credits »

Watch Now

From $1.99 on Amazon Video


1 video »


Episode cast overview:
Homer Simpson / Wiseguy / Guy with a letter / Barney Gumble / Gil Gunderson / Mayor Quimby / Key Man (voice)
Marge Simpson (voice)
Bart Simpson / Todd Flanders / Nelson Muntz / Ralph Wiggum / Joe Spuckler (voice)
Lisa Simpson (voice)
Hank Scorpio (voice) (as A. Brooks)
Additional Voices (voice)


Barney accidentally made Homer ride on the Duff Blimp for a joke. Meanwhile, Lisa finds a secret key to a hidden room at Springfield Elementary School; it is not what she expects at all but, she soon finds out a school mystery about a bus and some children.

Plot Summary | Add Synopsis


Animation | Comedy





Release Date:

15 May 2011 (USA)  »

Filming Locations:

Company Credits

Show detailed on  »

Technical Specs


Sound Mix:


Aspect Ratio:

1.78 : 1
See  »

Did You Know?


When Homer is driving through "Suicidal Moron Pass", the license plate on the front of the car is NABF14, the production code for this episode. See more »


Nelson Muntz: Little Miss Play-It-Safe, eh? Have a nice day. Just like the day before that...
[starts backing up slowly]
Nelson Muntz: ... and the day before that... and the day before that... and the day before that...
Nelson Muntz: [Through PA system] ... and the day before that... and the day before that...
Principal Seymour Skinner: Nelson, will you just tell everyone the lunch specials?
Nelson Muntz: Sloppy joes! And the day before that... Tater tots! And the day before that...
See more »


References Inception (2010) See more »


Bridal Chorus
Composed by Richard Wagner
See more »

Frequently Asked Questions

This FAQ is empty. Add the first question.

User Reviews

A Clever, Different Format for an Episode,
3 November 2011 | by (Ireland) – See all my reviews

500 keys is a fantastic Simpsons episode with a very well written storyline and loads of very funny scenes. The format of the episode is very clever and unique, it separates all five Simpsons members out in to four stories, which all come together very nicely in the end, they were all very enjoyable, Lisa's one was complicated and detailed, while Homer's was mostly comedy, it was a risky and different episode that worked. The only thing about the episode that I found a little unfulfilling was Bart's story, it was quite funny and entertaining while it lasts but it draws to a conclusion too quickly, he eventually gets involved with Lisa's story but I would have been happy if the plot in which he struggles to cause trouble was more developed. Lisa's plot is definitely the best, it was very cleverly devised, it plays out like an actual detective mystery, with twists and turns throughout and a pleasing conclusion, definitely the main reason why this episode is so great, but Homer travelling through Springfield on a blimp never failed to make me smile and laugh. Funny and very unique, 500 Keys is definitely one of the highlights of the twenty second season.

When Marge finds a large collection of keys, she separates it among the family members to see what they find.

1 of 4 people found this review helpful.  Was this review helpful to you?

Message Boards

Recent Posts
Teacher jesse-garcia12
They forgot the Cat Andthatismytwocents
Theme park jesse-garcia12
What is the worst thing Homer has ever done? Foo_Fighter82
How did Homer's mother die? Purple_Cloud_9
Why did they kill off Maude? Purple_Cloud_9
Discuss 500 Keys (2011) on the IMDb message boards »

Contribute to This Page

Create a character page for: