(Scene opens on the house.)
Phineas: (from inside) Okay, Ferb, let's get this early morning party started.
(Song: Quirky Worky Song)
(Cut to inside the house as Phineas is squeezing some oranges into a pitcher and Ferb is making pancakes. Cut to a cupboard. A chicken clucks and lays an egg. The egg goes down a slide and cracks into a frying pan. Cut to Phineas holding a tennis racket. He swipes a popped piece of toast with it. Ferb catches it and then some. Cut to Phineas by a percolator. He pours some coffee. Cut to Ferb putting some blueberries onto the plate. Phineas and Ferb wheel the breakfast out. Ferb returns to make the percolator disappear.)
(cut to Lawrence in his room)
(Lawrence and Reginald Fletcher imitate plane sound)
(cut to Lawrence's computer)
Reginald: Okay, prepare for landing. That's it, lad, don't let the turbulence throw you. Ha ha! Ha ha!
(cut to Lawrence)
Lawrence: Roger that, Papa Bear.
(cut to Reg)
Reginald: I'm so glad we can still have our Father's Day jaunt in the biplanes.
(cut to Lawrence)
Lawrence: Oh, yes, modern technology's wonderful. I know it's not quite the quite the same as...

Phineas: (him and Ferb walk in the hallway) Hang on, Ferb.

Lawrence (cont'd): ...the real thing but I suppose it's better than nothing.

Phineas: Whoa, Ferb, I know what else we're gonna do today. (walks in Lawrence's room) Surprise! Happy Father's Day, Dad. And you too, Grandpa Reg.
Reginald: Hello, boys.
Lawrence: Oh, how lovely. Breakfast in den.
Phineas: (reveals the Phineas and Ferb pancakes) Ferb and I pulled out all the stops.
Lawrence: What excellent likenesses! Ha ha ha! Thank you, boys.
Candace: Happy Father's Day, Dad.
Reginald: (on the computer) Hello, Candace.
Candace: (in Cockney accent) 'Ello, Grandpa Reg. (normal voice) Happy Father's Day.
Reginald: (on the computer) Thank you, love.
Linda: Hello, Reg. Are you having a "Grand"-Father's Day? (laughs) Hoo hoo!
Reginald: Ha ha ha! Good one!
Linda: I'll leave you boys to your Father's Day fun. Candace, are you ready to go?
Candace: Sure, mom. Bye, grandpa.
Reginald: 'Ey, where's Perry?

(cut to Perry as he enters by using a playground set and hovers in the air)
Major Monogram: Morning, Agent P. I see you're trying out the new SFU 2000. It's a lot of fun, but don't let your duties slide.
Carl: Agent P, what do you think of his Father's Day gift?
Major Monogram: Yes, it's a lovely tie, but I'm not your father! (to Perry) Anyhoo, Doofenshmirtz has plans to gum up the entire Tri-State Area. And we need you to check it out. Good luck, Agent P.
(Perry slides down the slide into the Doofenshmirtz Evil Incorporated building)
Doofenshmirtz Evil Incorporated!
(Perry gets trapped with gum)
Doofenshmirtz: Gotcha, Perry the Platypus! If you think this is a sticky situation, you better hold on to that fedora. Behold, the Gum-Under-The-Shoe-inator! I took all the wadded up chewing gum in the entire Tri-State Area and fed it into this -inator. Yeah, I know, it's really unsanitary. Why don't people just throw the chewing gum in the trash? Huh?
(Doofenshmirtz and Perry get shot by the -inator)
Doofenshmirtz: (sighs) Today just isn't my day. It's Father's Day. It's the hardest of the greeting card company holidays for me. My issues with Father's Day began back when I was a child.
(Flashback from Lawn Gnome Beach Party of Terror.)
Doofenshmirtz: (voiceover) Those were lean times for my father and our beloved lawn gnome was repossessed.
(End flashback.)
Doofenshmirtz: Okay, I know you've heard that one before, but...twice actually...but I really think that this is where my relationship with my father went awry.
(Resume flashback.)
Doofenshmirtz: (voiceover) I mean, he made me be that lawn gnome!
Mr. Doofenshmirtz: Bewegen sie nicht! ("Don't move!")
(End flashback.)
Doofenshmirtz: I mean, he was really specific, too. He made me memorize the serial number of that particular lawn gnome. (While he talks, Perry goes onto the computer and opens the Lawn Gnome Tracker app.) DAEHM23. If only there was some way to reunite him with, y'know, that specific lawn gnome, maybe he and I could start again. (Looks at the computer.) DAEHM23?! You found him with an online gnome tracker? Wow, there really is an app for everything now, isn't there? Well, let's see. It says it's still in Drusselstein! Now I can heal the old wounds between my father and me! (gets up and walks but is stuck to the chair) Oh, man that is one of my most brilliant ideas yet! (His pointy nose pops the huge bubble made from the gum.)

(Cut to the backyard where Phineas and Ferb are working on a biplane.)
Phineas: An exact replica of Grandpa's old biplane! Dad's gonna love this! (He and Ferb climb in and put on their helmets and goggles.) Let's try 'er out! (The plane takes off.) Now punch it! (Ferb pushes a button on a remote control and four jet engines come out from the wings and the plane increases speed.) Yeah!

(Cut back to D.E.I. as the roof opens.)
Doofenshmirtz: (offscreen) I know traveling by cannon is a little unconventional...
(Cut to reveal Doof wearing a pilot's uniform and carrying Perry in a baby carrier and climbing into a giant cannon.)
Doofenshmirtz (cont'd): ...but the cannon place was going out of business, so I got them at a volume discount. (lights the fuse) Hang on. (The cannon fires.) Woohoo!
(Vanessa arrives at the door with a basket.)
Vanessa: Happy Father's Day, Dad! Dad?
(Cut to an airborne Doof and Perry.)
Doofenshmirtz: Sorry for the lack of inflight meals or entertainment, Perry the Platypus, but one cannon can only go so far, so I set up a worldwide network.
(They land in another cannon somewhere in a field and take off again. Cut to a canon on an island. Doof and Perry miss their target and land in the water.)
Doofenshmirtz: Aw man! Missed it by that much!

(Cut to the backyard where the plane lands.)
Phineas: Perfect landing, Ferb! I'll go get Dad. (Cut to the sliding door. Phineas leads his father out.) No peeking, Dad! Keep 'em closed! Okay, open 'em!
Lawrence: (gasps)
Ferb: Tada!
Lawrence: (voice breaking in tears) Thank you so much, boys! I can't think of a better Father's Day gift!
Phineas: Actually, there's a hidden feature you might wanna check out.
Reginald: (emerging from the passenger seat) 'Ello, son!
Lawrence: D-Dad?! B-B-B-But...
Reginald: C'mon! Give us a hug!
Lawrence: (hugging his father) Oh, happy Father's Day!
Reginald: What do you say we go on our traditional Father's Day flight?
Lawrence: Race you to the cockpit!
Phineas: Have fun!
Lawrence: What are you two standing there for? You're part of the tradition now! Come on!
Phineas: Cool!
Reginald: Right then!
Lawrence: Here we go!
(The plane takes off.)
Lawrence: Wooooooooo!
(Song: Fletcher Family Flying Circus)
Lawrence and Reg: In our two wing aeroplane,
Doing tricks that look insane
To keep the peoples entertained
And leave them breathless.

Call us brave or slightly mad
Lawrence: I'm his son and he's me dad!
Reg: And I look really grand in plaid
But now I'm vestless!

Lawrence: Nice ad lib, Dad!
Reg: Thanks, son, I just roll with it.
Lawrence and Reg: Like you do!

(In harmony)  It's the Fletcher Family Flying Circus
Doing aerial acrobatics in the atmosphere
High above the stress and strife,
There's nothing here to irk us;
Just a father and a son together,
Keepin' our heads above the weather,
I wish that we could do this every year!

Barrel rolls and loop-de-loops,
Buzzing that encounter group,
Doing the Charleston on the wing,
Yes! We'll try almost anything!

A dim old man, an English bunt,
A crazy Russian circus stunt,
A Cuban eight, an inverted spin,
All while wearing this foolish grin!

It's the Fletcher Family Flying Circus
Doing aerial acrobatics in the atmosphere
High above the stress and strife,
There's nothing here to irk us;
Just a father and a son together,
Keepin' our heads above the weather,
I wish that we could do this every year!
We're the Fletcher Family and we have no fear!

(Cut to Drusselstein where Doofenshmirtz and Perry finally land...on a cat no less.)
Doofenshmirtz: Ah, Drusselstein! This way, Perry the Platypus. (Doof and Perry get up and the cat meows. Cut to outside Ye Olde Pawn Shoppe.) Okay, so the gnome tracker located my father's long lost lawn gnome to this location. (He opens the door and gasps.) There it is! (He picks up a lawn gnome, but it talks.)
Gnome: Hey, put me down!
Doofenshmirtz: Ah! I thought you were my father's lawn gnome.
Gnome: No worries. I get that all the time. Probably due to my height combined with my eccentric fashion choices.
Doofenshmirtz: Uh, yeah. Huh. Well, I'm looking for DAEHM23.
Gnome: (picks up the real lawn gnome behind him) Oh, yeah, it's been here for years. Here you go.
Doofenshmirtz: It is you! My father will be so happy! Well, maybe not happy, but anything is an improvement over surly and dismissive. Let the father-son healing begin! (He arrives at the old Doofenshmirtz house and takes Perry out of the baby carrier.) Wish me luck, Perry the Platypus! (Perry smiles and gives him a thumbs-up.)
(Cut to inside the house.)
Doofenshmirtz: (knocks and opens the door) Hello? Father? You're never going to guess what I brought y— (He trips on the floor mat and the gnome shatters to pieces.)
Doofenshmirtz's Dad: Oh, hello, Heinz.
Doofenshmirtz: (sadly) Hello, Father.
Doofenshmirtz's Dad: I see you've brought me assorted broken bits of pottery for Father's Day. Well, I suppose it's the thought that, um...counts. Your brother, Roger, remembered how much I loved that old lawn gnome, so he sent me this. (walks up to a giant lawn gnome) Look, it also makes espresso. (The gnome opens a compartment door and an espresso spout pours some into a mug, which Doofenshmirtz's dad takes out and sips.) Delicious. But, you know, rubble is...a nice gift, too.
Doofenshmirtz: (voice breaking in tears) Father's Day. And...okay, bye-bye. (leaves)
Doofenshmirtz's Dad: All zis way just to give me broken shards of potter— (gasps and sees the serial number) DAEHM23?!
(Cut to outside where Doof sits on the curb with Perry sadly.)
Doofenshmirtz: (sighs) Well, that could've gone better. (Perry consoles him.) Why do I even bother, huh? At least there's one relationship in my life that's worked out pretty well. Thanks for coming along, Perry the Platypus. Let's go home. (They walk away from the curb.) You are my rock. (Cut to a cannon.) And by that, I mean you're there for me, you're not made out of rock. You're actually made out of...well, platypus, probably. (They climb into the cannon, which fires.)

(Cut to the backyard where the Fletcher Family Flying Circus lands.)
Lawrence: Well, that was the best Father's Day flight yet! It brought back some some wonderful old memories and created a lot of new ones. Thank you, boys, for making this possible!
Phineas and Ferb: (hugging their father) Happy Father's Day!
Lawrence: Yes. Yes it is.
Reginald: Crikey! It's getting late! I best be on me way home. Mind if I borrow your new aeroplane?
Lawrence: Why don't you hang onto it 'til next year? I've got no room left in the garage anyway.
Reginald: Will do! Cheery-bye!
(The plane takes off just in time for Linda not to see it.)
Linda: Hi, honey! Hi, boys! So how was your day?
Lawrence: Oh, the boys and I spent a wonderful day flying with Father!
Linda: Ah, the internet is a wonderful thing.
Lawrence: Well, yes, I...pfft...s'pose it is.
Linda: Well, here's something special from Candace and me.
Candace: (giving her father a gift box) Here you go!
Lawrence: (opening the box) Oh, my! An exact replica of Father's biplane! Oh, it's perfect! (giving his daughter a hug) Thank you so much, sweetheart!
Candace: Happy Father's Day, Dad!
(The rest of the family join the hug.)

End Credits

Doofenshmirtz Evil Incorporated
(Doofenshmirtz walks up to the basket Vanessa left behind.)
Doofenshmirtz: (reading) "To the most evil dad in the whole world, Happy Father's Day. Love, Vanessa." Aw, a gift basket of switches and self-destruct buttons. (pushes a self-destruct button) That's my girl! (smiles)

(cut to Doof's dad; music starts; he attempts to repair a lawn gnome)
Doofenshmirtz's Dad: Bewegen sie nicht! ("Don't move!")