(Scene opens up with the camera zooming into the backyard.)

Phineas: So, Ferb, what do you wanna do today?

(Ferb shrugs.)

Phineas: What about Perry? What does he want to do?

(Perry chatters)

Phineas: Well, he's a platypus. They don't do much. I, for one, am starting to get bored, and boredom is something up with which I will not put! The first thing they're gonna ask us when we get back to school is "what did we do over the summer?". I mean, no school for three months. Our life should be a rollercoaster! And I mean a good rollercoaster. Not like that one we rode at the state fair...

(Flashback on a rollercoaster at the state fair. It goes over one tiny hill then ends.)

Fair Worker: Please exit to the left.

(End flashback.)

Phineas: Man, that was lame. Why, if I built a rollercoaster, I would... (Gets idea; angelic chorus plays) That's it! I know what we're gonna do today!

Linda: Phineas, Ferb. I'm gonna pick up a few things. You boys stay out of trouble, okay?

Phineas: Okay, Mom. (At Ferb) We're gonna build a rollercoaster! But should we get Y/n and Bronya to help?

(Ferb nods)

(Linda gets into the car; Candace comes over.)

Candace: I'm in charge, right? You did tell them I'm in charge?

Linda: Well techinally Y/n is the oldest so he would be in charge and most likely he would make Bronya his second in command.

Candace: But they don't take anything seriously like I do!

Linda: Relax, Candace, nobody has to be in charge.

Candace: But what if there's an emergency.

Linda: Y/n and Bronya both have PHD's and Medical Licenses, what could possibly happen that they couldn't handle?

Candace: What if a... What if a satellite falls out of orbit and crashes into the house? (smiles)

Linda: If that happens, you're in charge.

Candace: Yes!

(Meanwhile Phineas and Ferb make their way down the basement stairs where they hear a song playing.)

Phineas: Wow we hear her music a lot don't we?

(Ferb nods)

Phineas: They have good taste in artists. Alright Ferb, do you have the document for the code words for the week?

(Ferb nods and pulls out a piece of paper)

Phineas: Thank goodness for these.

(Phineas the knocks on the door and the music stops)

Y/n: This is a bucket.

Phineas: Dear God.

Y/n: There's more.

Phineas: No!

(The door then opens to reveal Y/n who takes off his goggles.)

Y/n: Sup Phineas, Ferb, what brings you two by today?

(Bronya then walks up next to Y/n)

Bronya: Sup.

Phineas: Yo, me and Ferb are gonna build a rollercoaster, you two in?

(Y/n looks at Bronya)

Y/n: How's our schedule looking Bronya?

Bronya: Well we just finished that government contract so we are clear for now.

Y/n: We're in.

Phineas: Sweet

(Ferb gives a thumbs up)

Candace: (she enters into the backyard) Mom says I'm in charge, conditionally.

(Y/n, Bronya, Phineas, and Ferb are working on something.)

Y/n: Aren't usually me and Bronya in charge since we're the oldest?

Candace: Well yeah, but the condition has changed.

Bronya: Let me guess, you're in charge if a satellite falls out of orbit and crashes into the house?

(Candace's jaw drops)

Candace: How did you know?

Y/n: I have a 200 IQ and Bronya has 199 IQ, also you are just predictable.

Candace: Okay ignoring that insult, what are you guys doing?

Phineas: Homework.

Candace: It's summer.

Y/n: Have fun waiting till last minute and then begging me to help.

Candace: Well, I'm watching you. (Goes through the door) And I'm in charge—conditionally!

Bronya: No-one cares!

(Candace walks into the house and the phone rings, which she answers.)

Candace: Hello? Oh, hi, Stacy! No, I can't get to the mall right now. Mom just went to the store, she left me in charge, well, you know, conditionally.

(Phineas and Ferb walk past with lots of wooden planks.)

Candace: And if you go, can you see if Jeremy is there? No, no, he's the cute one that works at Mr. Slushy Burger.

(Y/n and Bronya walk past, with steel beams.)

Candace: Yeah, he totally smiled at me the last time I was there. I just about died. No, I told you I can't, I'm watching my brother and stepbrother. Yes even Y/n and Bronya. Yes they are older but those two are just lazy.

(Phineas and Ferb walk past with sinks and toilets.)

Candace: Yeah, and they never get into trouble, 'cause Mom never catches them. One of these days though, I'm going to see that she catches them red handed.

(Y/n and Bronya walk past again, with a flamingo and a lion that roars loudly.)

Candace: Will you hold it down, I am trying to use the phone! (at Stacy) Mom left me in charge, so there will be no shenanigans today. What are they doing right now? Why do you ask? What do you mean you can see it from your house? See what?!

(Candace runs out to the backyard, she stares in shock upon seeing the rollercoaster, along with horror music.)

Candace: Phineas, what is this?!

Phineas: Do you like it?

Candace: (gets angry) Ooh, I'm gonna tell Mom, and when she sees what you're doing, you are going down! (runs off) Down! Down! Down! D-O-W-N, down!

(Y/n, Bronya, Phineas, and Ferb look blankly while she walks away.)

Phineas: We're gonna need a blowtorch and some more peanut butter.

Y/n: Okay the blowtorch I understand perfectly. But is the peanut butter in case we get hungry?

Phineas: Pretty much.

Y/n: Gotcha.

(Candace takes her bicycle and rides away.)

Isabella: Hey Candace, is Phineas... home?

Candace: Down, down, I say!

(Isabella walks into the backyard. Y/n is now wearing a tank top and is currently working a suspended rollercoaster cart. Bronya is sitting in a chair working on her laptop.)

Isabella: (hearts in eyes) Hey, Phineas.

Phineas: Hey, Isabella.

Isabella: What'cha doin'?

Phineas: Building a roller coaster.

Isabella: In your backyard?

Phineas: Some of it.

Isabella: Wow. Isn't that kind of impossible?

Phineas: As Y/n has taught me. Impossible is just what people say when they give up.

Isabella: Hey Y/n, Bronya.

Y/n: Sup.

Bronya: Yo.

Isabella: Hey, Ferb.

(Ferb waves with the hammer.)

Isabella: Does your stepbrother ever talk?

Y/n: Nah, Ferb prefers to be a man of action.

(Ferb hits the nail and then his nose.)

Isabella: Phineas, I was gonna go to the pool, you wanna go swimming?

Phineas: Kind of in the middle of something here.

Isabella: Oh, right. Okay, I'll see you later then. (Is about to leave but feels a hand on her shoulder) Bronya?

Bronya: Listen let me give you some Flynn boy advice. With them you can't give them hints, it does NOT work.

Isabella: How long did it take for you to get through to Y/n?

Bronya: Too long... Welp good luck.

Isabella: Thanks... (leaves)

Phineas: Okay. (at Ferb) Hey, Ferb! You got enough rivets up there?

(Ferb gives a thumbs up showing they have rivets.)

Phineas: Hey, where's Perry?

Y/n: Who knows.

Bronya: Probably. sleeping somewhere.

Y/n: I'm gonna use the restroom)

(Perry walks around the corner of the house. He jumps up, puts on a fedora. Y/n then comes from around the corner.)

Y/n: Off to work?

(Perry chatters)

Y/n: Yeah I know that me and Bronya are the only two allowed to know because we make most of your gadgets. Also, hole in the wall entrance today. Have fun, and if you see Firefly say hi.

(Perry nods and walks into a hole in the wall. He goes down a lift, into a lair, where he gets an "Incoming Message".)

Major Monogram: Good morning, Agent P. The evil Dr. Doofenshmirtz is up to his old tricks. For reasons unknown to us, he bought up 80% of the country's tin foil. I want you to get over to his hideout right away. Find out what he's up to and put a stop to it. As always Agent P, it is important that your cover identity as a mindless domestic pet remains intact except to Y/n and Bronya who work with us to stop evil. Now, get out there. We're all counting on you.

(Agent P jumps into a platypus-themed hovercraft, and flies tough a tunnel. He leaves through a stone and holds his fedora down to hide from Phineas and Ferb. He notices Y/n and Bronya giving him a small salute.)

Phineas: So, the way I see it, the fuel rockets kick in at the mall's parking lot, then we release the snakes during the corkscrew at the interstate. I'm gonna go get the snakes.

Y/n: I'll come with you. Hey, Bronya you gonna be okay with making the program?

Bronya: Of course I am, I'm the world's best programmer, five years in a row.

Y/n: Alright, see ya in a bit.

(Bronya gives a thumbs up and Ferb puts on his mask and starts using the blowtorch)

(Candace runs into the store)

Candace: Mom! You gotta come home, right now.

Linda: Did a satellite crash into the house?

Candace: No, no, no. You gotta see what Y/n, Bronya, Phineas, and Ferb are doing.

Linda: Seems like we've had this conversation before.

Candace: What do you mean?

Linda: I seem to recall you telling me that the boys and Bronya were training monkeys to juggle bicycles, and when I come home, there was a stunning lack of monkeys.

Candace: I still don't know how they cleaned that up so fast.

Linda: So, what's the emergency this time?

Candace: They're building a roller coaster!

Linda: Candace, seriously? I mean Y/n maybe because he has 3 PhD's and is working on his 4th but isn't Phineas a little young to be a roller coaster engineer?

(Phineas and Y/n talk to a man in a car factory.)

Factory Manager: Aren't you a little young to be a roller coaster engineer?

Y/n: Yes, Yes he is. Also I have a license for this.

(Y/n pulls out an ID Card and the Factor Manager nods)

Factory Manager: Good to see you again Mr. Flynn and for your younger brother Well, I must say, I'm very impressed, the forms all seems to be in order, although I'd never seen them filled out in crayon before So, if there's anything I can get you, anything at all, just let me know.

Phineas: Do you think we could borrow one of those gadgets?

(A robot arm fixing a car is shown)

Y/n: Oh Sam would love to tinker with that and Bronya is going to love programming it. Nice catch Phineas.

Phineas: Thanks.

(Y/n, Bronya, Phineas, and Ferb are riding the roller coaster that is being built by the robot arm. Bronya is sleeping in Y/n's lap.)

Phineas: Now, this is the life.

(Y/n kisses Bronya on the forehead and she smiles in her nap)

Y/n: Couldn't agree more little brother.

(The camera zooms in on Doofenshmirtz Evil Incorporated where Agent P swings into the building.)

Doofenshmirtz: Ah, Perry the Platypus, what an unexpected surprise. And by unexpected, I mean: COMPLETELY EXPECTED!

(Doofenshmirtz presses a button, which activates arms that grabs Agent P.)

Doofenshmirtz: I, Dr. Heinz Doofenshmirtz, have covered the entire eastern seaboard in tin foil, and when I put my giant magnet, next to my genius, Magnetism Magnifier, I will pull the East, in westerly direction, thereby reversing the rotation of the earth. You may ask yourself, why would he do this? What could he possibly have to gain? Well, let me just answer that question, I haven't really worked on all the bugs yet. I mean, tin foil alone costs a lot.

(Sam the enters the room and takes off her goggles and she notices Agent P)

Sam: Hi Perry.

(Agent P chatters)

Sam: Oh Y/n says hi. I'll make sure to call him later.

Doofenshmirtz: Ah Sam, I was just about to explain why I covered the entire eastern seaboard in tin foil.

Sam: Huh, I was wondering why you ordered so much Tinfoil.

(Back at the store)

Candace: But, Mom, I'd tell you, they're building it, and it's huge!

(Ferb puts up a poster, Candace comes over to read it.)

Candace: "Y/n, Bronya, Phineas, and Ferb present the Coolest Coaster Ever now open"? Mom! (runs off)

Pedro: Those four got a roller coaster? You think we get a discount if we bring the flier?

Dimitri: Maybe we better take it.

(They take it with them just as Candace brings Linda over.)

Candace: (Gestures toward the empty post, head turned away) There, look, look, look, see? I told you I'm not crazy, I told you!

Linda: (dryly) And you're not crazy because...?

(Candace turns toward the post where the poster was and screams.)

Linda: I see your point, Candace. No crazy person would scream at a post like that. I'll be at the dairy section if you wanna come yell at some cheese, or anything. (leaves)

(At the Flynn-Fletcher house, where the start of the coaster and a stage is. Ferb lets the kids into a tent and Bronya walks onto a stage up to the microphone as if she's about to speak, then steps out of the way as Phineas and Y/n come up. Phineas grabs the microphone as disco lights shine and rock music plays.)

Phineas: Ladies and gentlemen, boys and girls, children of all ages! May I present to you a spectacle most of the morning in the making: 

Y/n: The Coolest...Coaster...EVER!!!

(Ferb reveals the coaster. A bird files into it.)

Phineas: So, who wants to go first?

(Everyone raises their hands.)

Y/n: Excellent. BRONYA! GET THE WAIVERS!

(Bronya appears with a stack of papers and smacks Y/n upside the head)

Y/n: OW!

Bronya: Don't yell for me when I'm right here.

Y/n: Yes Ma'am.

(On the rollercoaster...)

Phineas: To fasten, insert the tab into the metal buckle. To release, just pull back on the—oops.

(Phineas drops the safety belt.)

Phineas: Well, you get the picture. Well, that's about it. Enjoy the ride.

(The car goes over the top, and stops, viewing the long drop.)

Y/n: Bronya everyone signed the waivers right?

Bronya: Yep.

Y/n: Alright then. GRAVITY DO YOUR THING!

(Down it goes; the car goes around the coaster, on the track. Everyone but Y/n and Bronya screams. The rollercoaster then goes through the drop of snakes.)

Phineas: Relax, they're just rubber!

(The car goes into a bucket of mud, then exits. Later, it goes through a car wash, to be cleaned from the mud.)

Y/n: Oh here comes the fun part. The AH-AH-AH-AH!

(The track is going up and down repeatedly, creating four "AH"s.)

(The car zooms around the Doofenshmirtz Evil Incorporated building.)

Doofenshmirtz: ...When I really make most of my money back, I-I-I want a really spacey real estate, and sell it again.

Sam: That was... anti-climatic.

(Agent P sends a screw at Doofenshmirtz, which he ducks for.)

Doofenshmirtz: Ha! You missed!

Sam: And here is where thing's get interesting.

(The screw flies to the roof and hitting a line, which throws it back at Doofenshmirtz's foot.)

Sam: Oooo... that's gotta hurt.

Doofenshmirtz: Aaaoow!! Ow, Ow, Ow, Aaooww!

(Doofenshmirtz jumps around and Sam whistles innocently as she releases Agent P who tips his fedora at her and then attacks Doofenshmirtz.)

(Agent P hits Doofenshmitz's foot.)

Doofenshmirtz: Aaaoow!!

(During the fight, Doofenshmirtz activates the Magnetism Magnifier.)

Doofenshmirtz: Now you are too late! Quake in your boots and watch helplessly, as the unimaginable electromagnetic forces, pull the eastern seaboard, thereby reversing the rotation of the Ea--

(All the tin foil releases from the buildings)

Sam: Oh that's not good...

Doofenshmirtz: Well... that didn't work.

(The tin foil forms into a giant ball, flying through the air)

Doofenshmirtz: And now, we have a two-ton ball of tin foil traveling 200 miles per hour directly at us! Quickly, we must separate the magnet from the Magnifier before it's too late!

Sam: I have something that might be able to help us! It's a project I've been working on!

Doofenshmirtz: Hurry Sam!

(Sam quickly runs off)

(At the store)

Linda: Now I know I have that club card in here somewhere. I always have it with me, but my purse is a disaster area, you know how it is.

(Candace goes outside and sees the coaster)

Candace: Oh, oh, oh, oh, oh! Mom? Mom!? (She rushes off.)

(Doofenshmirtz Evil Incorporated building)

Doofenshmirtz: It's no use! It's no use! We are doomed!

(Agent P sees a helicopter. He jumps onto the magnet and fires a grappling hook at it. He quickly wraps some of the rope around the magnet. The helicopter flies off, taking the magnet with it.)

Doofenshmirtz: You did it! You saved us, Perry the Platypus!

(Just as the ball of Tinfoil is about to hit the building something gets in front of it and stops it. Doofenshmirtz looks up to see a robot figure.)

Doofenshmirtz: Sam?

(The robot figure tosses the tinfoil ball high into the air and incinerates it. The figure the nods at Doofenshmirtz and flies off)

Doofenshmirtz: Huh, I guess she really is good with robotics. I'm so proud.

(The magnet pulls a piece of the Magnetism Magnifier onto it, and gets stuck on the coaster, which then follows the helicopter into the sky.)

(Candace pulls Linda into the parking lot, not noticing the coaster has been removed.)

Candace: Look, look, look, see?

Linda: (pause) Okay, I give up, what am I supposed to be looking at?

Candace: (turns to see the empty parking lot) No!! It's not POSSIBLE!!!

Linda: (going back inside) I'm gonna go get the cart.

Candace: IT WAS RIGHT HERE AND IT WAS HUGE!!! (sees the rollercoaster fly away) MOM!

Linda: (walks past, taking her cart) Time to go. I've got frozens.

Candace: Okay, so you think that Phineas and Ferb are still under that stupid tree in the backyard, and that Y/n and Bronya are in the basement, right?

Linda: Well, yes, that would be my guess.

Candace: Fine, then let's go home, now! (She pushes the cart.)

(Agent P sees that the helicopter is smoking and cuts the rope. He drops down onto the coaster and in the cart, right behind Y/n, Bronya, Phineas, and Ferb.)

Phineas: Oh, there you are, Perry.

(Perry chatters)

Phineas: Nice hat, Y/n.

(Y/n looks at the fedora)

Y/n: You know what, it is a nice hat.

(The car goes to the end of the track and flies onto a construction area and flings into the air.)

Phineas: Funny, I don't remember this in the blueprints.

Y/n: Eh, may or may not have had a gut feeling this would happen and I put it in mine.

Phineas: Fair enough.

(An airplane picks up the car by the tail)

Phineas: This part of it too?

Y/n: Yep.

(Candace sees the airplane from Linda's car.)

Candace: Hehehehehehehehehehe!

Linda: I worry about you sometimes, Candace.

(The coaster car drops down and onto the Statue of Liberty, bending and throwing it to the woods. It lands on a pine tree which bends so they end up in front of Mr Slushy Burger.)

Jeremy: Welcome to Mr. Slushy Burger, may I take your order?

Y/n: Hey Jeremy.

Jeremy: Sup. Same as usual for you and Bronya?

Y/n: That would be great.

(Jeremy hands Y/n and Bronya their food)

Phineas: Anyone want fries?

(The tree bends back and throws them to France, Paris)

French Man: Croissant?

Y/n: OH HECK NO! GET ME OUTTA HERE! ANY WHERE BUT FRANCE!

(Y/n pulls a lever as the car gets flung into orbit)

Y/n: Much better.

Bronya: You really hate the French don't you?

Y/n: I mean can you blame me?

Bronya: Not really.

Singing Voice: ♪ Aahh-Aahh-Aaahhh ♪

(A satellite flies by)

Phineas: You know, if that thing crashes into earth, Candace is in charge.

(The car begins to fall down towards Earth but is stopped and everyone looks to see SAM holding it)

Y/n: Sam? Is that you?

Sam: Yeah it's me. I finally finished it!

Bronya: Nice suit there Firefly. Mind helping us home.

Sam: If Y/n agrees to cuddle time later.

Y/n: YES!

(Sam and Bronya both giggle as Sam then flies the car back down to Earth)

(Linda pulls the car on the driveway and Candace jumps out.)

Linda: Okay, we're here, are you happy now, Candace?

(Horror music plays; Candace opens the gate to the backyard and doesn't see Y/n, Bronya, Phineas, or Ferb.)

Candace: Yes! (At Linda) See, Mom? I told you they weren't there!

(Candace opens the gate and gestures toward the tree with her eyes closed, as we hear a sound of leaves rustling. Linda pokes her head through the gate opening and smiles.)

Linda: Oh, hi, you guys.

(Candace opens her eyes and her mood changes to shock; cut to under the tree to show Y/n, Bronya, Phineas, and Ferb are suddenly here.)

Linda: Oh Sam, nice to see you.

Sam: It's nice to see you too Mrs. Flynn-Fletcher.

Linda: Come on Candace, help me with the groceries. (goes off)

Candace: But, but, but, but, but, but, but... (Continues under)

Linda: (comes back) Let's go. (pulls her away)

(Kids drop down from the tree.)

Kid: Hey Phineas, that was great.

Pedro: Way too cool.

Third kid: That was awesome! Can we do it again?

Y/n: Sorry folks, only one ride per customer.

(Isabella comes down from the tree.)

Isabella: That was great, Phineas. So, what are you gonna do tomorrow?

Phineas: Don't know yet.

Isabella: (pets Perry) Maybe you could teach Perry some tricks.

Phineas: Well, he is a platypus, they don't do much.

Ferb: They're the only mammals to lay eggs.

(Pause)

Y/n: I mean he's not wrong, also Ferb. Did you forget that Perry is male?

(Ferb shrugs)

Isabella: Cool. See you tomorrow. (goes to the gate) It really was the coolest coaster ever. You guys make a great team.

Phineas: Well, a brother is a brother, but I couldn't have asked for a better one than Ferb and Y/n. Also having Bronya and Sam as future sisters is pretty good too. You know what I mean?

(Ferb burps rudely and Y/n highs five him.)

Phineas: Oh-ho-ho, man! I could smell the peanut butter!

Y/n: Nice one Ferb, but I can do better!

Isabella/Bronya/Sam: *sighs* Men....

Phineas: So, what should we do tomorrow? There's a world of possibilities. (pause) Maybe we should make a list!

(The coaster car explodes in the tree, a car alarm and a dog barking can be heard.)

Candace: (from inside) Mom!!

Linda: (from inside) Give it a rest, Candace!

Y/n: Well I don't know about you guys but... (he picks up Bronya and Sam and throws them over his shoulders) This guy has cuddle time and no-one is gonna interrupt that. Also Sam, you gotta show me and Bronya the suit in full detail later.

Sam: Sure thing.

Bronya: Dope.

[End of the episode]