Doof's inator takes up so much power that it ends up causing a blackout over all of Danville. Phineas decides to make this the best blackout ever, by making a very large and ambiguous invention.
!!Tropes

* BigBlackout: It's what the [[ExactlyWhatItSaysOnTheTin episode's title exclaims]], and it's caused thanks to Doofenshmirtz's "Big-Sad-Eye-inator" using so much power and exploding.
* BlackComedy: Doofenshmirtz's trap is so escape-proof that he "couldn't get that guy out". The film pans over to a skeleton stuck in another trap, much to Perry's horror. [[BaitAndSwitch It's made of plastic.]]
* BrickJoke: Phineas tells Candace to put on a helmet and a mouthguard. However, during the song, when there are lights, Candace is seen wearing a helmet, but no mouthguard. After the song, it is explained that she swallowed it. Also serves as a CallBack by Doof at the the end when he gets the device from the jetpack squad.
* BorrowedCatchphrase:
** Buford enters the backyard by saying, "Whatcha doin?", making Phineas think that Isabella said it.
** When realizing that Agent P has escaped, Doof says, "Hey! Where's Perry? The Platypus?"
* ByTheLightsOfTheirEyes: Pretty much the entire episode is basically just black with nothing but the eyes. It's also a huge LampshadeHanging of the trope. This certainly saved a lot of money on animation!
* CallBack: One of the things that Doof is given is someone's [[WesternAnimation/PhineasAndFerbTheMovieAcrossThe2ndDimension watermelon]].
* CoolShades: Before the power comes back on, we only see Linda, Lawrence and Candace's eyes in the backyard, and Linda says she feels something pointy. When the blackout is over, it is shown that Phineas and Ferb are wearing sunglasses, which is why we couldn't see their eyes.
-->'''Phineas''': You're right, Ferb. We're cooler even in the dark.
* EasilyForgiven: Doofenshmirtz attempts to invoke this trope with his Big, Sad Eye-inator. His idea is that people will let him do anything as long as he [[WoundedGazelleGambit looks pitiable]] enough.
* HonkingArrivingCar: Candace recognize's her stepfather's two-honk horn.
* ImplausibleDeniability: Because of the blackout, Baljeet cannot find Buford anywhere.
-->'''Buford''': And you're not gonna!\\
'''Baljeet''': Buford, is that you?\\
'''Buford''': No!
* InMediasRes: The episode starts with Perry already trapped and Doofenshmirtz explaining the Big, Sad Eye-inator to him.
* ItsTheBestWhateverEver: Phineas and the gang are determined to make it the best blackout ever.
* NoodleImplements: Bereft of any actual information about Phineas and Ferb's newest contraption, Candace tries to catch her mother's attention by hissing that they're using a winch. It doesn't work.
* PowerOutagePlot: The power goes out all over Danville thanks to Doofenshmirtz's "Big-Sad-Eye-inator" using so much power and exploding. The power is later turned back on when Perry goes over to the Danville power plant and turns on a red switch.
--->'''Worker 1''': That's all it was? That big red switch over there?\\
'''Worker 2''': You think I would've know that. I mean I got a Ph.D.\\
'''Worker 1''': You work that into every conversation.
* PuppyDogEyes: Doof's Big-Sad-Eye-inator gives him these. Apparently, they work better in the dark because when the power returns, his eyes are bigger than his head, freaking out Roger.
* ShoutOut: Candace says "Dad, tear down this fence!" in a nod to UsefulNotes/RonaldReagan's famous "Tear down this wall!" speech at the Brandenburg Gate of the UsefulNotes/BerlinWall. (To hammer home the reference, "Hail to the Chief" plays in the background during this bit.)
* TheUnreveal:
** One of the kids in the backyard has an eyepatch.
--->'''Eyepatch Kid''': (ominously) But is it my left eye or my right eye? You don't know...
** Whatever ''was'' Phineas and Ferb's Big Idea? But whatever it was, it was not exactly their intention to ''ride'' it. Pretty much lampshaded by the song.
--->'''Candace''': But what ''was'' it? What ''was'' it?!