(The scene opens up at the front yard of the Flynn-Fletcher residence, where an apron clad Lawrence is carrying a birdhouse towards a tree)
(Song: "My Undead Mummy" [instrumental])
Lawrence: (To three songbirds) Look at that, my fine feathered friends! (He mounts his handiwork onto the tree trunk) Not a bad bit of work, even if I do say so myself. Just wait till you see the hidden surprise. (He pushes a red button on the front of the bird house, which bears the words 'home tweet home'. Its walls spring outward, revealing various miniature items including a fountain and a spiral staircase) Oh, nothing? Not even a sausage? No matter. (He pushes the button once again and the birdhouse folds back to its normal state) Wait until Linda and the kids see it. It'll blow their tiny minds. Well, not their tiny minds, that's not fair.

(The scene shifts and the UNcovery Channel masthead is displayed on screen)
Announcer: You're watching the UNcovery Channel. We now return to Rrrrr?
Narrator: (The camera shifts to the boys who are watching the television show intently) Many believe that in the 1950s, a UFO crash landed in Roswell, New Mexico, but the scientists had no idea what the advanced technology was or how it worked. To find out, they used a process called reverse engineering. By closely examining the individual parts, they were able to build their own craft and figure out what it does, and how it does what it does. Way to go, reverse engineering! The reverse engineering craze reached its zenith in 1982 when new wave band Zanzibar released their smash reverse engineering-related hit, "What Do It Do?"
Band Member: ...Do do, do do do...
Phineas: Cool! Hey, where's Perry?

(Scene shifts to Perry's lair)
Major Monogram: Hey, Carl, where's Agent P?
Carl: Oh, he came in early today, sir.
Major Monogram: He did? Heh. Well, good for him. Well, I guess we're done. I'm going home.
Carl: Me, too?
Major Monogram: No, not you.

 Doofenshmirtz Rocket-powered Jet Skiff! 
(Traps activating)
Doofenshmirtz: Ha! Close, but no... Cigar! See, Perry the Platypus, my new jet rocket skiff has more hidden traps than... (Snaps fingers) Um, uh—What's something with a lot of hidden traps? Huh, wow, I felt so confident going into that sentence. Man, okay. Anyway, you might be wondering why I got such an early start on my evil scheme today. You see, my dating life has been a seemingly endless series of disappointments. It all started at a drive-in movie.
(Flashback to the '80s at the Danville Drive-In)
(Song: "That's Wings, You Turkey")
80's Heinz: (singing along with the radio) That's wings, you turkey (coming out of the car) Okay, the coast is clear! You can come out now! (Linda emerges from the trunk)
80's Linda: Eww. It's grody back here!
80's Heinz: Well, on the bright side, you got in for free, so... we'll just split the cost of my ticket, right? Right?
80's Linda: You know, I could've gotten in the trunk, like, a block away instead of when you first picked me up at my house.
80's Heinz: Wow, you just love to live in the past, huh? Is that like a thing with you?
80's Linda: (sighs) Whatever. Let's just try to enjoy the rest of the evening.
80's Heinz: (does a robot dance) I am a happy robot, likey what I hear. I'm just kidding; that's a thing I do. C'mon, hop in!

(Heinz and Linda get in his car)
That's wings, you turkey
Radio Announcer: You were listening to: "That's Wings, You Turkey" by King of Loud. And here's a new one from Zanzibar: "What Do It Do?"

(Song: "What Do It Do?")
(The song has dialogue under)
Do, do, do, do, do, do!
Do, do, do, what do it do?

What'cha gonna does when you don't know what it do?
Do, do, do, do, do, do, do! What does, what does, what does, what do it do?
Do, do, do, what do it do?

(During the song)
80's Linda: Oh, turn it up! I love this song!
80's Heinz: Eh, it's okay, I'd say it's in my top seven, eight favorite songs about reverse engineering.
80's Linda: Makes me want to be a pop star!
80's Heinz: Ha! Yeah right, and I'm going to rule the world!
80's Linda: Well, why not?
80's Heinz: Yeah, like I could do that.
80's Linda: Maybe instead of, you know, the whole world, uh, start... small, with the Tri-State Area. (dramatic chord plays) Hey, the movie's starting! You have to put the speaker thing on the car.
80's Heinz: Nah-nah-nah. Check this out: (picks up a device) I built this awesome device that transmits the movie sound in fifth-dimensional stereo! I just plug this in here and Voila! (does a robot dance) I am a clever robot. Bing-bong, bing-boing.
(The device starts emitting electrical sparks, which effects all of the speakers in the theatre, and the screen, which explodes and launches into the night sky.)
80's Heinz: Huh. So can we hold hands now?
80's Linda: Take me home.
80's Heinz: Fine. Get in the back.
(The screen falls down and crash-lands on the snack bar.)
Doofenshmirtz: (voiceover) And I never saw her again.
(End flashback)

Doofenshmirtz: Oddly enough, she did become a pop star later! I'm still struggling with the whole Tri-State Area thing, but y'know, the dream is alive. (walking to the other side) Anyway, they recently reopened that drive-in, dredging up all these unpleasant memories for me. So, naturally, I built this. (He gets trapped, and trips, causing the huge device to fall off the rocket-powered jet skiff.) Oh, really?! Really?!!

(Cut to the Flynn-Fletcher house. The device crash lands in the front yard. Candace walks out the house.)
Candace: Okay, Mom, I've gotta get to Stacy's! Love ya! Bye! Oop! (sees the device) Mom Mom! Mom!! C'mere! Look what Phineas and Ferb made in the front yard! Quick!
Linda: Oh, yeah. You're in such a— (zoom in on Linda's shocked expression) The boys built that?!
Candace: (excitedly) Yes! They're always making crazy things like this! See?! See?!
Linda: What is it?!
Candace: Well, obviously, it's a— Why don't you ask/bust them?!
Phineas: Ask/bust us what?
Linda: Do you mind telling me what this is and why you built it in our front yard?!
Phineas: Um...we didn't build this, Mom.
Candace: Ha! Quick! Bust 'em—Wait. You didn't?
Phineas: Not that I'm aware of. no. Ferb? (Ferb shakes his head.)
Linda: No one is going anywhere until we figure out what this is and where it came from!
Phineas: Hmmm... Let's see what this red button's all about—
Linda: Don't...touch it! (Candace and Phineas look at their mother while their attempting to touch it. Ferb has his shoe off and attempts to press it with his foot.) Nobody touches it! I'm calling your father.
(Phineas looks at the device and smiles at his brother.)
Phineas: Hey, Ferb, reverse engineering, huh? Uh? I know what we're gonna do today!
Candace: Think again, Bucko! Mom said "No touchee-touchee!"
Phineas: We don't need to touchee-touchee. We have a portable electronic scanner, gumption, and another portable electronic scanner.
Candace: Well, I'll be watching you closely, so don't think you can get one—
Phineas: All done, Ferb? Cool! Let's get reverse engineering!

(Cut to Lawrence at a presentation.)
Lawrence: And here's the 17th century Whiskershire spring stick, which belonged to the Earl of Whiskershire. (A man dressed in royal garments and a mouse costume appears on screen. Lawrence's phone rings.) Oh, 'scuse me for a second. Hullo.
(Cut to Linda in the house.)
Linda: Honey, do you know about the thing in the front yard?
(Cut back to Lawrence)
Lawrence: (referring to the birdhouse) Oh, yes, of course I do, honey. I made it myself. Do you like it?
(Cut back to Linda.)
Linda: You...made that?!
(Cut back to Lawrence.)
Lawrence: Ahem. Look, darling, I'm in the middle of something right here, so I'll have to phone you back.
Linda: (on phone) But—
Lawrence: Okay, honey, but don't press the red button on it, will you? I want to be there when you see it, okay?
(Cut back to Linda.)
Linda: Well, okay, but I'm really not very comfortable with—
Lawrence: (on phone) Cheers, love! Bye!

(Cut to the rocket-powered jet skiff, which is jetting over Africa. Cut to on board the skiff, where Doof and Perry are now in different traps.)
Doofenshmirtz: You know, in retrospect, I probably went a little overboard with the traps on this thing. Alright, I'm gonna try to reach the release switch for the trap holding your arms. Then you try to reach the steering wheel and change our course away from Mount Kilimanjaro. Interesting trivia...
(Song: "Kronk for Hire" (instrumental))
Doofenshmirtz (cont'd): (like a cheesy tour guide) Mount Kilimanjaro is actually comprised of three volcanic cones: Kibo, Shira, and the one that we're about to crash into, Mawenzi. Cool, huh? (Doof struggles to get to the button until finally pressing it.) There! Oh. Oh, that wasn't the release. Who knows what that did?

(Cut to the front yard. The device begins buzzing and steaming. Cut back to Doof.)
Doofenshmirtz: (reaching for the bottom button) This one should be the right— it! (Perry gets released) Quick! (Perry jumps onto a cage and steers the skiff away from Mawenzi. He falls backwards and gets trapped...again.) You know, Perry the Platypus, I just— A golf course! A golf course has a lot of traps in it! That's what I shoulda said.

(Cut back to the front yard. Linda approaches the device and her daughter.)
Linda: Well, it turns out your father is responsible for this—Hold on, is it...buzzing?
Candace: Yes. Yes, it is.
Linda: Okay, stay calm! (grabs and drags her daughter) Just move away from it!

(Cut to the backyard, where Phineas, the gang...and Irving are in lab coats standing before a duplicate of the device and a chalkboard with diagrams on it.)
Phineas: Friends, bullies, Irving, at 0900 hours, a UCO (or Unidentified Crashing Object) landed in our front yard. We reverse engineered a piece-by-piece duplicate of the strange object. We have called you here to help us discover what this object is and how it works.
(Song: "What Do It Do?")
Zanzibar: What'cha gonna does when you don't know what it do?
Do, do, do, do, do, do, do!

It's way too big to be a buckle, and too bland to be a belly dancer!
Or when it tries to guess your height, it's never right unless you're three-foot-two.
When you come or go, you can't tell if it waves goodbye or waves hello!
And in the library it's useless 'cause it don't care when the books are due!
Do, do, do, do, do, do, do.

It doesn't seem to understand the game is not rock-paper-scissors-spaniel!
Instead of picking up the trash it started picking Lady Liberty's nose!
It makes a lousy baseball umpire or brow-wiper for bongo players!
And when it walks a dog it never really pays attention where it goes!
Do, do, do, do, do, do, do.
Do, do, do, do, do.
What do it do?

(Cut back to the presentation, where Lawrence shows a slide of a bunch of townsfolk dressed as mice.)
Lawrence: Soon, the entire village of Whiskershire began following the Earl's lead to, of course... (phone rings again) Uh, do forgive me. I-I-I'm awfully sorry. Hello?
(Cut to Linda in the front yard.)
Linda: Lawrence, you have to come home right now! This thing is freakin' me out!
(Cut back to Lawrence.)
Lawrence: Uh, L-Linda, my dear, I love you, but you couldn't have chosen a worse moment to go completely bonkers! I'm sorry, but I've got to call you back! Bye!
(Cut back to the front yard.)
Linda: (very Candace-esque) Ohhhh, he doesn't believe me!! He said I sound crazy!!
Candace: (gasps in realization) Ohhhhh, reeeeeeally???
Linda: Yeah! You know I'm not imagining this!
Candace: Of course not! Gosh, that must be so frustrating to have someone not believe you when you're telling the truth!
Linda: Oh, you don't know the half of it.
Candace: That feeling you have right now: that's how I feel every single day when you don't believe me about what Phineas and Ferb are doing! Now that you finally understand, would you come with me to the backyard?
Linda: Why?
Candace: Now, keep in mind how Dad just made you feel, okay? Phineas and Ferb have reverse-engineered and built an exact duplicate of this thing and at this very moment, they're trying to figure out what it does by forcing it to belly dance and work in a library. (smiles)
Linda: Candace, honey, I love you, but you couldn't have chosen a worse moment to go completely bonkers!

(Cut to gay Paris, where the skiff is flying past the Eiffel Tower.)
Doofenshmirtz: (yelling below) Pierre!! (giggles to Perry) Did anyone look? A-hee-hee-hee! I betcha, like, half the people down there are looking around, like (fake French accent) "Who called my name?" (laughs in his normal voice)

(Cut to the backyard where Isabella and Baljeet are sitting at a dinner table with a candle on it.)
Baljeet: You know, Isabella, I sometimes wonder if it was mere coincidence that it was you and I chosen to portray the young, happy couple.
Isabella: "Chosen?" Baljeet, you charged to that empty chair like a crazed wolf.
(Phineas approaches the table with the device, both dressed a maitre d' and a waiter, respectively.)
Phineas: Ah, here we are, madame and monsieur.
(The device spots something. POV shot from the device as it locks its target onto the candle.)
Phineas: And what can I get for you this afternoon?
(The device drops its tray and swipes the candle off the table.)
Phineas: Ah-buh-bup! (the device stops) Give. (The device approaches Phineas, bowing apologetically, and gives him the candle.) Hmm... Interesting.

(Cut to the front yard. Linda and Candace are now in a fox hole behind some sacks of potatoes dressed in a pot and a colander respectively, as if they are watching enemy lines in a war. Linda looks at the device through binoculars.)
Linda: Okay, there's been no change in the last ten minutes. I should call your father.
Candace: You know, Mom, I understand. Obviously, you're not gonna come see what Phineas and Ferb are up to until this is resolved. So here's what we're gonna do! First of all, no more calling Dad! If I don't convince you to come home to bust the boys after a couple of calls, I go get you!
Linda: But what if he doesn't wanna come with me?
Candace: Did that ever stop me?
(Linda smiles sneakily.)

(Cut back to Lawrence.)
Lawrence: This statue, which stands outside the Whiskershire Rectory, still holds the Earl's actual spring stick, yes. The spring stick is used as such: it's placed in front of you so as to spring the hidden mousetraps to avoid capture. Now some suggest—
(Linda marches onstage and pushes her husband off.)
Linda: Move it, Fletcher!
Lawrence: Oh, any questions?
(Everyone in the auditorium raises their hands.)

(Cut to Whiskershire.)
Doofenshmirtz: (offscreen) Ah, the quaint town of Whiskershire. It's a great place to fly nilly-willy through, manacled to a rocket skiff this time of year.
(Perry takes out a pin and unlocks his trap and escapes. He dodges the next trap and sees the spring stick on the statue. He hangs onto the bottom wing and swipes the stick. He uses the stick to spring all the hidden traps, and then steers the skiff back to the Tri-State Area.)

(Cut back to the backyard.)
Phineas: Friends, bullies, Irving, we've reached our conclusion as to the purpose of the object that landed in our front yard. We believe that it is an anti-romance rocket created to scan for, and then eliminate romantic elements from potentially amorous situations.
Isabella, Baljeet and Irving: Ohhhhhh.
Buford: So it's not a wedgie machine?

(Cut to Linda and Lawrence in the station wagon. Linda is giggling in the manner of her daughter.)
Linda: Hehehehehehehehehehehehe...
(Cut to the front yard.)
Candace: (on the phone) Hehehehehehehehehehehehe... This is gonna be awesome, Stace! So when they get home, I'm gonna drag both of them into the backyard and it'll be a busting feeding frenzy!!!
(Song: "Busting Feeding Frenzy")
Candace (cont'd): (dancing crazily) Bustin' feedin' frenzy, stay out of the water

(Cut back to the rocket skiff. Perry jumps over the edge.)
Doofenshmirtz: W-W-Wait a minute! Perry the Platypus, where are you—? Oh!
(Agent P's parachute comes out of his bag.)
Agent P!
Doofenshmirtz: Curse you, Perry the Platypus!

(The spring stick falls from the rocket and presses the red button.)
Candace: Bustin' feedin' frenzy, stay out of the water
It's a bustin' feedin' frenzy, stay out of the water
(While Candace keeps dancing, the device buries the spring stick and launches. It sees the duplicate in the backyard with a heart in its eye.)
Barry White soundalike: Oh, yeah. I like the way the sunlight glistens off your chrome
(The two devices fall in love and launch off into the sun.)
Phineas: Wow. Two anti-romance rockets falling in love.
Buford: That's what I call "ironing".
(Cut back to the dancing maniac known as Candace.)
Candace: It's a bustin' feedin' frenzy, stay out of the water
It's a bustin' feedin' frenzy, stay out of the water
(The station wagon pulls up.)
Linda: There! Tell me that's not terrifying!
Lawrence: (looking at his daughter) I'm so sorry I doubted you.
Candace: Going down down down at the busting feeding frenzy stay out of the water!!!
Linda: (overlapping) Wait...But...Candace, where did that thing go?
Candace: (stops dancing) Hmmm. I don't know! But, Mom, you and Dad hafta come to the backyard with me right now and see what the boys are— (Sees the two devices rocketing over the house leaving a puff of smoke in the shape of a heart. She sighs.) Nevermind.

(Cut to the gang...and Irving in the backyard.)
Isabella: I wonder what would make someone want to build something to destroy romance in the first place.
Ferb: Well, if you reverse-engineer the human heart, you're bound to find love at its core.
Buford: And...gross smushy red stuff!
Ferb: Yes. Love and gross smushy red stuff.
Irving: And ventricles!
Ferb: Actually, I think ventricles are already included in gross smushy red stuff.
All but Ferb: Yeah.