S6E14: Bart's Comet
Homer, what if this doesn't work? Then I have a backup plan.
See, while the unprepared are still sitting around twiddling their thumbs and going--
Doo doo doo Da doo doo doo doo doo Doo doodle doodle Doo doo doo doo Doo doo doo ba ba dee-- Dad! The plan!