The episode begins with Richard and Nicole getting ready for a parent's evening at school. The doorbell rings, and Nicole is greeted by a babysitter Richard arranged for online, believing the job to be about literally "sitting on babies." Disgusted, she slams the door on him, after which Gumball and Darwin present themselves as viable alternatives. Anais is horrified at the suggestion, but as their parents leave, Gumball promises not to disappoint.
Right from the start, Gumball and Darwin prove to be as overly-protective as possible, not letting Anais go upstairs out of fear of a potential accident, destroying their television to prevent commercials from corrupting her, and mismanagaing a subsequent electrical fire. Through it all, Anais proves more adept, properly extinguishing the fire and pointing out the holes in their logic, but ultimately, since Nicole put them in charge, she's powerless.
Meanwhile, Nicole and Richard are waiting for the parent-teacher meeting outside of Miss Simian's classroom. Nicole tries to calm Richard down, reasuring that their adults now and that Miss Simian has no power over them, but their subsequent encounter only rings true to the contrary.
To cheer Anais up, Gumball and Darwin decide to take her for a walk in the park, but she is dismayed at being attached to a child leash in doing so. While on the walk, Marvin teases her with a dog biscuit, causing her to angrily bite his hand; seeing this, Gumball and Darwin assume her to be hungry, and take her back home. They present her with a virtually inedible lunch, then proceed to chew the food up for her, which she then blasts in their faces with a straw. Seeing as there is a big mess, Gumball and Darwin make Anais take a bath.
Anais reaches her breaking point when they refuse to let her even bathe out of fear that the water is too dangerous, instead insisting she dry clean herself. She orders them to leave, then, behind their back, continues to fill the bathtub. Darwin hears this, but Anais says that she just flushed, which reminds Gumball that Anais needs to wear a diaper so she doesn't have an "accident."
Sick of her brothers' ridiculous demands, she starts running around the house while Gumball and Darwin chase her. Unbeknowst to the three, Anais forgot to turn off the faucet, and the water slowly overflows out of the tub. Anais manages to lock her brothers outside on the roof while she taunts them by deliberately disobeying their rules. She starts climbing down the ladder of their bunk bed to go take a bath "with real water" (as Gumball and Darwin forbid), but falls into the rising water which is flooding the house. Unable to open the window or the door, Gumball and Darwin are forced to enter through the sewers, coming out of the toilet inside to rescue Anais. The fireplace is the only opening to the outside, so they swim into it and are rocketed out into the sky from the chimney before falling painfully onto the sidewalk.
Back at school, Richard unintentionally reminds Nicole that the kids are still home alone, which shocks Nicole into speeding back home.
When the two arrive back home, Richard tries to calm Nicole down and assure her that nothing went wrong, but as she opens the front door, all of the water spews forth, knocking them onto the lawn. Nicole, furious, approaches the kids and demands to know who was responsible. Anais is about to take the blame, but Gumball wants to be responsible for once and confess it was his fault instead. Upon seeing the furious face of her mother, however, he blames Darwin. The family then proceeds to give reasons why it was not their own fault and blame others, ultimately landing on Richard being inadequate at choosing a proper babysitter. With no one else left to blame, Richard blames the Internet. Ultimately, the whole family decides to go with that excuse, thus ending the episode.
Anais: And you chose to demonstrate that by smashing the TV in front of me?
Gumball: It was the responsible thing to do.
[Darwin and Gumball chuckle again]
Anais: Even though you set it on fire.
Gumball: It's not on fire. [Looks over to the TV to see it is engulfed in flames] Oh, it is on fire. [Grabs Darwin by the cheeks and screams] FIRE!
[Gumball goes off screen and rushes in with a bucket of water]
Anais: Stop! Don't throw water on an electrical--
[Darwin spits a stream of water on the engulfed TV, electrocuting himself and Gumball]
Anais: --fire. You should always use a fire extinguisher or if unavailable, baking soda. [puts out the fire with an extinguisher] But most importantly call an adult or the emergency services.
Gumball: Yeah of course, but ours was a responsible demonstration of what not to do in case of an electrical fire.
Anais: How could Mom put you in charge? [Opens a book]
[Darwin kicks the book she was reading out the window]
Anais: What is wrong with you?!
Anais: Ridiculous, and look at the mess you're making!
Gumball: It's a small price to pay for your safety.
Darwin: You're too young to understand.
Anais: Excuse me, but who makes your breakfast every day?
Gumball and Darwin: You, of course.
Anais: And who helps you with your homework?
Gumball and Darwin: You.
Anais: So I should be in charge.
Gumball: But who did Mom put in charge?
Gumball: So who has to do what we say?
Anais: [sighs] Me.
[Scene cuts to Elmore Junior High; Richard and Nicole are waiting outside Miss Simian's room]
Richard: Uhh, I feel like I'm in one of those dreams. The ones where you go to school naked.
Nicole: Oh, come on, Richard, stop being so dramatic. We're the parents now. There's nothing she can do to you.
Lucy Simian: You get an F minus in parenting! Next!
[Banana Joe's parents come out of the room crying]
Lucy Simian: Oh, the Wattersons.
Lucy Simian: Are you aware that your husband isn't wearing any pants?
Back to the Kids
[Scene cuts back to the Watterson house]
Gumball: Aw, look at that grumpy little face.
Darwin: I know what will cheer her up. How about a walk in the park?
Anais: Hmm, yeah I guess that could be okay.
[Gumball and Darwin are at the park, Anais is on a leash like a dog]
Gumball: Come on, it's for your own safety.
Marvin: Oh, isn't she lovely? How old is she then?
Gumball: She's four now.
Marvin: Well now, you want a biscuit? Huh? You wanna have a taste of this? You wanna have a little taste of this? Well, you can't have it, that's right, cause it's mine. Whoo, I was just teasin' ya, you want a little taste of it?
[Anais bites Marvin]
Marvin: [Yells] Oh, you bit me!
Gumball: You know what this means?
Darwin: She must be hungry!
[Scene goes back to the house]
Gumball: It's time for num-nums! We have a mackerel sandwich, a potato, and a little something for dessert.
[Gumball lifts up the lid of a plate and an old boot is revealed; Anais is visibly disgusted]
Anais: Are you kidding me?
Gumball: [Gasp] Of course! That food is way too chunky for a little baby like her, she could choke.
Darwin: I know what to do.
[Darwin takes the tray from Anais, he and Gumball begin to chew the food for her grossly and vomit it back onto the tray; Anais is disgusted; Gumball draws a smiley face in it]
Gumball: Bon appetit! [Places a straw on the food]
Anais: Alright, you asked for this. [Inhales and blows the food all over Gumball, Darwin, and the walls]
Gumball: Okay, bath time.
[Scene cuts to bathroom, Gumball is testing the water temperature]
Gumball: Ah, just right.
Darwin: Isn't water dangerous?
[Gumball gasps and tosses Anais back onto the rug]
Anais: How do you expect me to wash myself without water?
Gumball: Haven't you heard of dry cleaning?
Anais: Fine! Get out of here!
[Slams the door on Gumball and Darwin]
Gumball: They grow up so fast.
[Anais is seen filling up the tub with water]
Darwin: Is that water I hear?
[Anais opens the door a little]
Anais: No! I just, uh, flushed?
Gumball: Oh, speaking of which, we're gonna need you to wear this.
[He holds up a diaper]
Gumball: Well, we don't want you to have any accidents.
Darwin: Very responsible thinking, Gumball.
Gumball: Hm, thanks.
[They both chuckle]
Gumball: Now be a big girl and...
[They both gasp, Anais is at the bottom of the steps]
Anais: There's no way I'm wearing a diaper!
[She runs away, Gumball and Darwin chase after her, they forget to turn off the running water in the bathroom]
Gumball: Get back here!
[The water rises to the top of the bath, then some spills onto the floor]
[They chase her through the living room, making a huge mess in the process]
Gumball: Come back, Anais! You can run, but you can't hide!
[She hides under the sofa]
Gumball and Darwin: Run! Hide!
Gumball: Put it on!
[Anais runs upstairs and barricades herself in Gumball and Darwin's room]
Gumball: Open this door, young lady! Don't make me tell Mom you've been a bad baby!
[Gumball somehow stretches his eye in the crack of the door]
Gumball: [Screams] Aah! She's not in there, she ran out the window!
[They kick open their door and climb onto the roof]
Gumball: Oh, what's Mom gonna think? We're in so much trouble!
[Anais sticks her head out the window]
Anais: You goons really walked into that one!
[She shuts the window]
Gumball: Anais, let us in.
Anais: Babysit yourselves on the roof until Mom and Dad come back. [She walks away from the window]
Gumball and Darwin: Anais! Anais!
[They hit the window repeatedly, Anais is on Gumball's bed]
Anais: Oh look, a book, I hope I don't give myself a papercut.
[She giggles and bounces on the bed]
Gumball and Darwin: Anais!
Anais: Oh, no, no diaper. I surely hope I don't have an accident, on your bed!
Gumball and Darwin: Anais! [They both notice something offscreen] Anais!!
Anais: And you know what I'm gonna have now? A nice relaxing bath, with real water!
[Anais begins to slide down, Gumball and Darwin's room is nearly flooded, Anais lands in the water and gasps]
[The scene cuts to Richard and Nicole sitting on the front steps of the school]
Richard: Well, it could've been worse.
Nicole: Are you kidding me? Look at the bill, how do you set fire to a swimming pool?
Richard: I know, pretty good huh?
[Nicole gives him a death glare]
Richard: That you're always there to keep an eye on them?
[Nicole remembers the kids are still home alone, gets in the car and speeds home]
[Scene goes back to their house, Anais is on Gumball's desk, struggling to open the window]
Anais: Do something!
Gumball: Get on the bed and stay where you are. We'll figure out a way to rescue you.
[Gumball and Darwin are on the porch]
Gumball: Don't worry! I'll smash the door in- [Headbutts the door and nothing happens except him recoiling in pain] Ah! You wouldn't know where the keys are by any chance, would you?
[Darwin looks in the window, the keys float by underwater]
Darwin: Somewhere safe.
Gumball: Aw, what are we gonna do?
[A manhole is seen, the scene then cuts to the house's bathroom, where Darwin and Gumball have evidently swum up the sewer pipe and gone out the toilet. Gumball and Darwin swim in their room where Anais is waiting. Gumball coughs up two chunks of water that he was holding in]
Gumball: Hey, how's it going?
Anais: I don't know, how do you think it's going?
[Darwin is shown trying to open the window, which is not opening]
Gumball: Okay, take a deep breath.
[Anais and Gumball breathe in and dive underwater]
[They swim down the stairs, where Darwin finds the keys, but before they can open the door the keys are sucked out of his grip by the water pressure coming from the fireplace. Anais gets the idea to go out the chimney, so they move the couch and swim up and are caught in a violent geyser erupting from the chimney]
Anais, Darwin and Gumball: Woohoo!
[They all celebrate]
Gumball: Good job everyone!
[The geyser suddenly stops, the kids are caught in midair, they all look down and start to scream, Gumball pulls out the diaper he put in his pocket]
Gumball: Hey, don't worry, we can use this diaper as a parachute and float safely down to-
[They hit the ground face first with a loud smack, they hear a car in the front yard and it turns out to be their parents coming home]
Anais: [Gasps] They're back!
Anais, Darwin, and Gumball: Oh, no.
[They duck back around the corner, Nicole storms out of the car while Richard cautiously follows]
Richard: See, honey? I told you there was nothing to worry about.
[Nicole opens the door and a huge burst of water hits them, leaving them filthy and stunned]
Nicole: Thank heavens you're safe!
[She runs up to Anais and gives her a hug]
Anais: So, you're not angry at us for trashing the house?
Nicole: Oh, no. Angry doesn't begin to cover it!
[Scene cuts to the interior of the house, with the whole family there]
Richard: How do you burn a TV underwater?
Nicole: Who is responsible for this!?
[Anais, Gumball, and Darwin look shocked]
Anais: Mom, it's my--
Gumball: No, I've got this.
Anais: No, Gumball, it was me that left the faucet running!
Gumball: Please sis, let your brother be "responsible" for once in his life.
[Anais gets teary eyed, and runs over to give Gumball a hug]
Anais: Thanks, Gumball.
[Gumball inhales and begins to tell Nicole what happened]
Gumball: Mom... [Sees Nicole with flames in her eyes], it was Darwin. [Points to Darwin]
Darwin: WHAT?! It was her that flooded the place! [points to Anais]
Anais: I thought you were going to take the rap! Anyway, it was clearly Mom's fault. She was the one who left Gumball in charge.
Nicole: Well it- it's Dad's fault for not finding a proper babysitter!
Richard: Well, none of this would've happened if it wasn't for you! [Points to a broken computer on the floor]
[Scene falls silent for a few moments]
Nicole: Um, who are you blaming here?
Richard: The internet?
All: [Everyone settles the dispute and agrees] Yeah, that's good enough.