While the boys build a giant tire swing, Buford removes a particular part which accidentally turns Candace into a fly. Meanwhile, Doofenshmirtz suffers from evil scientist's block.
Tropes:
- Acquired Error at the Printer: Monogram received a message that Doofenshmirtz is at the "shark", but Carl informs him it was a typo, that he's at the "park", not the "shark".
- Added Alliterative Appeal: Major Monogram instructs Agent P to "Stop Doof from doing the doing that Doof does... do."
- Amnesiac Resonance: The kids briefly break out into "Summer (Where Do We Begin?)"Phineas: Yeah, we all know the song... [goes wide-eyed] But I'm not exactly sure how. [Everybody stares blankly at the screen for a few seconds, before continuing on as if nothing happened]
- During this scene, Perry has a very apt look of concern on his face, since he worries that his cover is about to be blown again.
- Animal Species Accent: While turned into a fly, at one point Candace says her brothers are "so buzz-ted!"
- Animal Talk: In fly form, Candace can talk to other flies, but not to humans; they only hear her words as "buzz buzz buzz".
- Are You Pondering What I'm Pondering?: After Phineas gets inspired to improve on the tire swing, he says, "Ferb, I know what we're gonna do today?", to which Buford quips, "Uh, hatch mosquitos?", to which Phineas replies, "No."
- Bait-and-Switch:
- Once Phineas accuses Buford of tampering with the machine, Buford says, "Uh... Oh no! If I catch the mug what did this... Yeah, I'm on it."
- When the giant tire swing ends up in outer space, an astronaut seemingly comments on this.Astronaut: Whoa, that is weird! We're in a space shuttle and the shuttle program ended years ago.
- Buffy Speak: Buford tinkered with the machine by "taking the doohickey out of the thingamawhatsit".
- Call-Back:
- The gang at first suggests rehashes of old ideas. Buford first suggests making a "super-duper-rollercoaster", and Isabella suggests making a "Portal to Venus" since they already made a portal to Mars.
- In response to Phineas' asking what summer was all about, the others start singing "Summer (Where Do We Begin?)", prompting Phineas to point out that they all know the song... but no one's sure how.
- Creator Cameo: The fly with a human head that Candace talks to briefly is played by and modeled after writer Martin Olson (also the father of Olivia Olson, the voice of Vanessa).
- Dodgy Toupee: As a fly, Candace discovers that Bobbi Fabulous (the bass player for Love Händel) has been wearing a wig this entire time.
- Evolving Credits: As always, with a new season comes different still shots at the end of the theme song, with stills from Phineas and Ferb The Movie: Across the 2nd Dimension, "Doof Dynasty", "Moon Farm", "The Remains of the Platypus", "Escape from Phineas Tower", "Tri-Stone Area", "Excaliferb!" and "Bully Bromance Breakup".
- Forced Transformation: Candace is turned into a fly, with her human head still on a fly body. Later, she meets a fly that was apparently hit with a ray that turned his head into a human's.
- Inventional Wisdom: Phineas and Ferb invent a machine that makes sorbets that also shoots rays that turn humans into flies if some wires get crossed.
- Lampshade Hanging: While complaining about his "evil scientist's block", Dr. Doofenshmirtz remarks that it feels like this summer has been going on for four years.
- Pretentious Pronunciation: While inside Jeremy's room, Candace overhears him planning to take her to the rodeo, so she dresses up as a cowgirl. However, it is revealed that the place Jeremy plans to bring Candace to is a fancy restaurant with its name pronounced "Ro-DAY-o."
- Shout-Out: During the montage of Doof getting his groove back, at one point, Doof does a painting in the style of René Magritte's The Son of Man, which depicts the surrealist artist with an apple in place of a face, but with Perry in place of Magritte.
- Special Guest: Robert Lopez (Avenue Q, The Book of Mormon, Frozen (2013)) returns to co-write the title song.
- Training Montage: Somehow Doof has gathered from Perry's expression that he will "lead [him] through a series of bizarre and seemingly unrelated exercises that will help [him] get [his] groove back".
- Ungrateful Bitch: Somewhat zig-zagged. After being turned back to normal, Candace profusely thanks her brothers, but then returns to say "I mean, 'You are so busted!'", but then returns to thank them again.
- Whole-Plot Reference: To The Fly (1958). At one point, Candace says the iconic line, "Help meeeeeeeee..."
- Writer's Block: Doofenshmirtz has "evil scientist's block", preventing him from coming up with fresh, clever ideas for evil schemes.Doofenshmirtz: I was going to make a "good idea-inator", but then I thought that would be counterproductive, since that already had "good" in the title, so then I made a "bad idea-inator", which... just gave me this. See where that got me.
- You Know What They Say: When the giant tire swing crushes Doof's perfect inator, Doof relates what his uncle Boris used to tell him, "When life's goin' well, a giant tire comes along and smashes your inator."Doofenshmirtz: We all thought he was crazy at the time, but now it seems rather prophetic.
