500 Keys (S22E21)
S22E21
When Lisa discovers a set of keys that unlocks every door in Springfield, she stumbles upon a secret chamber hidden beneath the elementary school.
Show
The Simpsons
Episode
S22E21
Air Date
May 15, 2011
Season 22 Episodes
S22E01
Elementary School Musical
S22E02
Loan-a-Lisa
S22E03
MoneyBART
S22E04
Treehouse of Horror XXI
S22E05
Lisa Simpson, This Isn't Your Life
S22E06
The Fool Monty
S22E07
How Munched Is That Birdie in the Window?
S22E08
The Fight Before Christmas
S22E09
Donnie Fatso
S22E10
Moms I'd Like to Forget
S22E11
Flaming Moe
S22E12
Homer the Father
S22E13
The Blue and the Gray
S22E14
Angry Dad: The Movie
S22E15
The Scorpion's Tale
S22E16
A Midsummer's Nice Dream
S22E17
Love Is a Many Strangled Thing
S22E18
The Great Simpsina
S22E19
The Real Housewives of Fat Tony
S22E20
Homer Scissorhands
S22E21
500 Keys
S22E22
The Ned-liest Catch