500 Keys

General

500 Keys is the twenty-first episode of Season 22.

Synopsis

When the Simpsons discover a collection of keys to every door in Springfield, Lisa stumbles upon an eerie hidden classroom beneath Springfield Elementary School. When she shares her discovery with Principal Skinner, the secret room mysteriously disappears and he takes the only key away. A determined Lisa uses her detective skills to lead her back to the room to solve an old school mystery.

References

← Season 21 Season 22 Episodes Season 23 →
Elementary School Musical • Loan-a Lisa • MoneyBart • Treehouse of Horror XXI • Lisa Simpson, This Isn't Your Life • The Fool Monty • How Munched Is That Birdie in the Window? • The Fight Before Christmas • Donnie Fatso • Moms I'd Like to Forget • Flaming Moe • Homer the Father • The Blue and the Gray • Angry Dad: The Movie • The Scorpion's Tale • A Midsummer's Nice Dreams • Love Is a Many-Strangled Thing • The Great Simpsina • The Real Housewives of Fat Tony • Homer Scissorhands • 500 Keys • The Ned-liest Catch