(Scene opens up on Phineas and Ferb in their backyard.)
Phineas: Ah, here's the doo-hickey that fuses with your spinal cord.
Isabella: Hey guys. What'cha doooin'?
Phineas: Today, we're gonna fuse our nervous systems with Dad's laptop and surf the web using only our cerebral cortexes.
Baljeet: Wow! Surely that would be quite an exciting project.
Phineas: Oh, hey Baljeet. Why are you dressed like a vegetable samosa?
Baljeet: Because today is the Tri-State Area Unification Day! I learned all about it in Assimilation class. You see, the Tri-State Area was the bi-state area until our founder, the great John P. Tristate, uttered the immortal words:
John P. Tristate: The, uh, bi-state area should be united with that adjacent area right over there.
Phineas: But we knew that. I was just wondering why you're dressed like a vegetable samosa.
Baljeet: Oh, that. My Uncle Kamal is doing an exotic cuisine float in the parade, and I'm the...
Phineas and Baljeet: Vegetable samosa!
Buford: Hey!
Baljeet: Buford?
(Buford walks up, and is also dressed up like a vegetable samosa.)
Buford: I thought I was supposed to be the vegetable samosa!
Baljeet: Why can we not both be vegetable samosas?
Buford: Oh, sure, two vegetable samosas! Why don't we all just dress like vegetable samosas? In fact, why don't we just all dress like mashed potatoes and take the word exotic right off the sign?!
Baljeet: Buford, wait!
Buford: No, man. It's over! I'm gonna go find another nerd!
Baljeet: But what about the Tri-State Area Unification Day parade?
Buford: What? Is that what this parade is for?
Baljeet: Does no one know what today is?
Buford: Well, excuse me, but that adjacent area was founded by my great-uncle Otto H. Adjacent! He didn't wanna be no part of no Tri-State Area unification, and neither do I! The blood of Otto H. Adjacent runs through these veins, and blood is thicker than water! (leaves)
Baljeet: Well, mango chutney is thicker than blood.
Buford: (Yelling) You're dead to me!
Phineas: (to Ferb) Parade? I love parades. Ferb, I know what we're gonna do today instead! We're gonna... Hey, where's Perry?

(In Perry's lair)
Major Monogram: Ah, there you are, Agent P. Well, let's get down to brass tacks... (reading his clipboard) What's this? "Happy passive-agressive relationship day"? Oh, is that today?
Carl: That's okay, you probably weren't gonna get me anything, anyway.
Monogram: Weel, I completely forgot.
Carl: No, no, you know I didn't even want a present.
Monogram: Anyway... Where were we? For some reason Doofenshmirtz has purchased a tow truck. Which isn't evil in itself, but he may be planning on towing something evil, so, check it out.

Linda: Candace? Are you ready for our girl's day out?
Candace: Just a sec mom! (She goes outside) Aha! Wait a minute. Are you guys just out here arranging kiddie wagons?
Phineas: At the moment.
Candace: Hmm, carry on. (Candace gets into the car with Linda) All clear, luckily the boys aren't up to anything.
(In the backyard, a large animatronic John P. Tristate is lowered onto their kiddie wagons)
Phineas: A little to the left. There you go.
Linda: Candace, you have to promise me that you won't obsess about Phineas and Ferb.
Candace: Yeah, sure Mom, I promise.
Linda: Don't just promise this time. Rise your right hand. Do you Candace Gertrude Flynn, solemnly swear not to obsess about your brothers, or you'll suffer the pharaoh's curse?
Candace: The pharaoh's curse?
Linda: Yes or No?
Candace: Okay, yes.
Linda: Okay, now we can ave fun.

Doofenshmirtz Evil Incorporated
(Perry bursts through the floor)
Doofenshmirtz: Perry the Platypus? (Doofenshmmirtz activates a trap, trapping perry in a door) Hahaha! You like that? I call it my "Indoors-inator". I got the idea from the Perry-shaped hole you left in my wall, and in my bathroom door, a-and in my fridge. Man you were hungry that day. Anyway, here's my evil plan. (He reveals his new -inatr) Ta-da! I'm calling it the "Duplic-8-inator". Get it? Duplic-, then the number "8", then -inator. I'll bet you're wondering what it does, huh? Here I'll show you.
(He fires off the -inator)
Farmer's Wife: I can't believe you started a monkey basketball team, and you've only got one monkey.
(The ray from the -inator hits the monkey, duplicating that monkey eight times)
Farmer's Wife: Oh great, now three of them are going to have to sit on the bench.
Doofenshmirtz: See? It duplicates everything eight times. When I zap those streets there will be eight time the traffic, and Danville will come to a standstill! That's where I will make off like a bandit. You see I bought this tow-truck off the internet, I'm going to call it the "Tow-inator" or something. And open a service, and then I'll go and... 'Course it'll be hard for me to drive anywhere, with all that traffic. T-that's a bridge I'll cross when I get there.

Nerd: (From atop a building) I've never been bullied into stopping a parade before. What should I do?
Buford: (Sighing) I don't know if this is working out. Can you talk in a Indian accent?
Nerd: Indian accent? No. I can do an English accent, instead! (Speaking with an English accent) Hello gov'! Top of the mornin', toodle pip! Last night Mr. Governor, my toilet was broken in two.
Buford: (He sighs) Actually that was pretty good.

Phineas: Okay everyone, let's show everybody what Tri-State unification is all about. Cue Love Händel!

(Song: "Tri-State Area Unification Day")

The Tri-State Area was the Bi-State Area
With an adjacent area right over there!
They put it all together, now there's no use denyin'
This parade is all about our area unifyin'!

There's only one thing we care about
We want you all to stand up and scream and shout!

It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!

(Buford and his Nerd release a fire hydrants water, attempting to re-route the parade)

It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!

Phineas: Ferb, water hazard ahead. Commence operation: unforeseen circumstance.
(Ferb drills a hole through the ground, allowing the parade to continue on it's intended route)

It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!
It's the Tri-State Area Unification Day!

Buford: Ahh, nugget!
Nerd: (Speaking with an Italian accent) That's a too bad. Maybe you should a dress like a policeman and a re-reoute a the parade.
Buford: (After a slight pause) If that wasn't such a good idea, I'd flatten you.
Nerd: Momma mia. That was a close.

(At Bobbi's Hair Emporium)
Linda: See Candace? Isn't this nice just to get away and enjoy a day together?
Candace: You're right Mom, this is the best. I'm not even going to think about– Mm, you know. I'm not even going to say their names.
Linda: That's the spirit.
Candace: I'm just going to sit here and enjoy, Ooh, the parade coming by. Haha, look at that kid in the cute little car. (She notices that the kid is Phineas) Gah! (Candace slaps both hands over her mouth) Mom! Ah! What am I doing? I am blocking my view. What my brothers do doesn't affect me. Letting it go for just one day. (She takes a breath) Nails. Happy relaxing fun.
Linda: You say something, honey?

(Buford and his nerd dressed as policemen redirect the parade toward the junkyard)
Buford: Now they're headin' for the junkyard. Removes gravitational pull, it'll be impossible to escape. Am I thinkin' of a junkyard, or something else?
Phineas: Ferb treacherous terrain coming up. Execute operation: Thing in our way.
(Phineas's car scoops up the front half of the parade, the floats shrink down, and begin walking on four legs)
Buford: (Watching) AHHHH! Otto H. Adjacent will be avenged!

Doofenshmirtz: Now, which button was it? Because one of these buttons just makes it fire will-nilly all over the place. And, I don't want to hit that one by mistake. (Perry uses his tail to knock on the door that is holding him) Oop, someone's at the door. I'll be right there. Oh excuse me Perry the Platypus, what can I do- (He opens the door, freeing Perry, who punches Doofenshmirtz into the Dupic-8-inator, setting it off) Oh see there, that's, that's the willy-nilly button. (Perry dives at Doofenshmirtz, while the -inator fires off randomly)

Candace: Mom, this place is so fancy-shmancy.
Linda: I just hope it isn't too noisy with that silly parade going on outside.
Candace: Believe me, I'm trying to tune it out.
Linda: So, what looks good to you?
Candace: (Blocking her view of the parade with her menu) Remember the pharaoh's curse. Wait! It doesn't count if she sees them herself! Hey mom, I bet you can't turn your head 180 degrees like an owl.
Linda: (Turning her head) Nope, just ninety.
Candace: Hey, can you show me that twisty yoga move you do again?
Linda: Maybe after lunch, dear.
Candace: I'm curious what the back of you chair looks like, can you turn around and show me?
Linda: Okay, Candace, what's up?
Candace: Mom! Why can't you just turn around!!??
Linda: (turning, just as Phineas and Ferb's floats leave) Okay you want me to turn around? I'm turning around. Can we just eat lunch now?!
Candace: (pauses) Fine...

Buford: (From atop a building, overlook the parade) If that parade makes it to the end, my hopes for the Adjacent Area secession are through. I gotta stop it.
Nerd: (Speaking with a German accent) What is your next plan? I know it is going to be something clever!
Buford: That's it! The other accents were amusing, but that one's just offensive. (He hops onto one of the passing floats)
Nerd: (Still speaking with the accent) Wait! What about me?
Buford: I'm firin' you as my nerd.
Nerd: Das ist nicht gut. (This is not good.)
(A stray beam from Doofenshmirtz's Dupic-8-inator hits the small balloons on the kids' floats, duplicating them eight times; it causes them to lift up off the ground.)
Isabella: Well, that's weird that our floats are floating away.
Phineas: Yeah, well, they are called "floats".
Buford: (From atop one of the floating floats) What the–? (He unties a singular balloon, that pulls him away)

(Perry and Doofenshmirtz continue to fight, and Perry manages to get Doofenshmirtz to fall off his building onto a nearby floating balloon)
Doofenshmirtz: A platypus balloon? (The balloon passes by a billboard with a man wearing a fedora, and the balloon picks the hat up.) A Perry the Platypus balloon?!

(At a shoe shop)
Linda: Candace I'm having a great time with you today. See how relaxing to os when you're not abscessing about your brothers?
(Pause, Candace strains and groans.)
Candace: I can't take it anymore!! Mom, I really tried to my best to give you a day, but it's...the boys. The boys! They're in the parade! With giant floats! So come on, you've gotta bust them. (Grabs her and runs off)

Buford: (Still floating on the balloon, and seeing the Tri-State area) Wow, it's all just one, big place. No Bi-State area. No Adjacent Area, It's all just one big Tri-State Area, right over there! (The string he was holding onto rips off the balloon, opening a hole on the balloon) Uh-oh. Mamma!
Doofenshmirtz: You know this balloon is actually– (He is cut off, as the balloon flutters about wildly) AHH! Curse you Perry the Platypus Balloon!!
Baljeet: (Seeing Buford fall) Oh no! Buford is in trouble! I must do something! (He goes to a man selling balloons) Please, my bully is in trouble, let go of all of your balloons.
Balloon Man: Yeah, okay. (He releases all of his balloons)
Baljeet: Thank you.
Balloon Man: No, thank you, vegetable samosa.
(Buford grabs onto some of the balloons and slows his fall.)
Fighter jet Pilot: Uh, did you guys see that? Let's investigate.
Phineas: What we really need is a grand finale, so spectacular, that people will always remember Tri-State Area Unification Day.
Isabella: Hey what's that?
Buford: (Coming down from his balloon, then releasing them) Happy...Tri-State...Unification...Day! Woo-Yeah!
(The squad o Fighter jets fly overhead)
Fighter jet Pilot: Yeah, just some Unification Day Parade stunt.
Phineas: That'll do it. Hey Buford great finale.
Isabella: Yeah, it was really, really nice.
Buford: Nice? Ah, now I gotta go do some'in' to balance out the universe. See ya' on the news. (He walks off)
Baljeet: Wait, wait, no Buford. No. No. No. Please don't. (A red liquid splashes Phineas, Ferb and Isabella) I was going to eat those jelly doughnuts.
Buford: Missed ya' Baljeet.
Baljeet: Right back at ya' buddy.
Ferb: An thus the universe is balanced.

End Credits

(On a curb)
Linda: Candace!
Candace: Behold, Phineas and Ferb have taken over the parade!
(Phineas, Ferb, Isabella, Holly, Ginger, and Irving are seen towing their wagons in the parade)
Phineas: Hi mom!
Isabella: Hi Mrs. Flynn-Fletcher.
Irving: Hi Phineas and Ferb's mom. Say Cheese! (He takes a picture)
Linda: Oh, how adorable!
Pharaoh: Excuse me. Are you Candace Gertrude Flynn?
Candace: (pauses) Yes.
Pharaoh: Curse you. (He walks off)
Linda: I tried to warn you, honey.