Krusty is strapped for cash. So Lisa offers to help in this Simpsons scene.
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Did Principal Skinner make a mistake when he offered his prized student a ride on a submarine. "Yellow Subterfuge" is the seventh episode of the show's 25th season.
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The Simpsons Season 25 Episode 7 Quotes

Bart sweetie, this is an opportunity for you to turn things around...yet again. And I believe in you...yet again.

Marge

Lisa: You could do what Everybody Loves Raymond did.
Krusty: Go off the air while I'm still good? That horse has left the stable, gone to the glue factory and has been used to make art projects.