The Simpsons S22E21 500 Keys
The episode in brief
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.
FAN DESK VERDICT A top-shelf entry. Not quite canon, but you’ll be quoting it all week — the fan desk says don’t skip.
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Where it sits in the season
Where to watch S22E21
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S22E21 FAQ
When did The Simpsons S22E21 air?
The Simpsons S22E21 (“500 Keys”) first aired on May 15, 2011.
Where can I watch The Simpsons S22E21?
In the US, The Simpsons season 22 — including this episode — is available on FX, Hulu, Disney+, fuboTV, DirecTV On Demand, Spectrum On Demand, YouTube TV, FOX One Amazon Channel, Hulu on Disney+, Amazon, Fandango at Home, and AppleTV.
Is The Simpsons S22E21 a good episode?
Fans rate The Simpsons S22E21 (“500 Keys”) 8.1/10, which puts it in the great tier for The Simpsons.