The Loud family believe that they are safe from pranks on April Fool's Day, because prankster Luan is away at camp.
The siblings (minus Luan) are having a meeting in Lori and Leni's room, debating on how to survive the upcoming April Fool's Day. Lisa suggests cryogenically freezing Luan, but is left with horrified expressions, while Lana and Lola opt to wearing "prank-proof" hazmat suits. As they continue to toss ideas around, Leni comes across an ad in her magazine for a special "Clown Camp", happening during April Fool's Day. Despite the high price tag, Rita and Lynn Sr. readily agree to the plan. At dinner, they present Luan with the offer, who is excited, but is disheartened at the fact that the offer is only available on April Fools Day. However, the family coaxes her into going, and Luan eventually agrees. After dropping Luan off at the camp, the family quickly drives off.
As the family begins heading home, Vanzilla breaks down, so the family decides to spend the night at a convenient motel. After Lana says prayers for her animals, the family goes to sleep. Unfortunately, Lincoln can't sleep, due to a cricket chirping noisily. He tries to turn on the light to find the cricket, but the switch he finds makes the TV blare loudly, to his family's annoyance. As Lincoln desperately tries to fix the problem, the whole room goes mad with malfunctioning appliances. Lana finally shuts everything down, finding the problem. It turns out the wires behind the switch are all mixed up. If that wasn't surprising enough, Lincoln discovers the cricket is fake, and is actually a prop from Luan's favorite prank store. Rita tries to call Luan to prove that she can't prank them, but her daughter's voicemail sadistically confirms that everyone has fallen into her trap. As everyone begins panicking, pranks begin to befall onto the family:
Lisa, claiming it's safer in the room, sits down on the bed, when suddenly, the bed folds in on her, trapping her in the wall. Lisa tells her family to go on without her.
As the family runs on the pathway, the wooden boards begin breaking apart, causing Luna to fall into a giant block of gelatin. Lynn tries to help her, but Luna tells her family to save themselves, as she begins sinking into the gelatin.
The family arrives to the lobby, but are afraid to open the door. The siblings vote who will open it by playing "Nose Goes", and Leni loses by touching her ear instead of her nose. She opens the door, and an inflatable clown flings her onto the motel sign, covered in fly paper, and modified with a laughing Luan neon sign.
The family enters the lobby, where the employee gives them a key for a new room. Lola takes the key, and enters the designated room, but it's actually a janitor's closet. Worse, a skunk sprays Lola, causing her to faint.
Lana takes the key, and heads off to the actual room. However, fearing that it could be like the prank Leni fell victim to, grabs a janitorial cart, and rams the door down, however she ends up falling into a pit full of pies. Unfortunately, Lana's face swells up, causing her to realize that the pies are filled with rhubarb, which she's allergic to.
Lori, unable to take it anymore, jumps into Vanzilla to drive off, but the airbags deploy, causing her to lose one of her eyebrows.
The family seeks refuge in the laundry room. As they hide, Lily spots a rattle on the floor, and begins waddling towards it, wanting to grab it. Rita, however, stops Lily from grabbing it. However, a bunch of laundry falls onto her, rendering her immobile.
As the family attempts to leave, Lucy accidentally triggers a rope, causing some liquid to spill onto her. Suddenly, she completely turns white, realizing the liquid that spilled onto her was bleach.
With Lynn Sr., Lincoln, Lynn, and Lily remaining, Lynn Sr. suggests on what to do next, but as they discuss, a fishing line snags Lily, and a monkey gets lowered into Lily's place. As Lynn Sr. tells Lynn to take herself and Lily to a safer place, the monkey begins attacking Lynn.
Lynn Sr. tells Lincoln that they should head to the rooftop. However, Lincoln discovers his father looking at his arm in suspicion. Lincoln looks at his father's arm, and discovers it's actually a list of all the places where they got pranked, causing him to realize that he was aiding Luan. Lynn Sr. escorts his son into a closet, and admits that he was helping Luan. He explains that a few weeks ago, while taking a drive, Luan approached him, and said she needed help in pulling off her biggest April Fools prank yet. He made the advertisement for the clown camp, and had bought a huge section of land just to set up the fake entrance. The van breaking down was actually due to one of Luna's fog machines, and Luan was observing them all along, not wanting to miss out on her family getting pranked. Luan is also revealed to be in disguise as the motel employee. When Lincoln questions why he did this, Lynn Sr. says that Luan was going to give him a prank free decade. Lynn Sr. eventually breaks down, regretting taking part in Luan's schemes instead of going against her. Lynn Sr. then realizes that he can redeem himself if he gets back at Luan, and Lincoln immediately goes along with his plan.
As Luan watches over the security cameras, she witnesses Lincoln and Lynn Sr. walking into the elevator. However, the elevator breaks down, and Lynn Sr. calls Luan over the elevator phone to come and fix the elevator. Luan, disguising herself as the employee, fixes the elevator, when suddenly, an inflatable clown shoves Luan, resulting in her falling into the numerous pranks her family got themselves into, ending with her being lifted into the air by Lana and Lola's "prank-proof" hazmat suit. As the family begins cheering that they managed to get back at Luan for all the mistreatment they've endured, Luan tells her family that they may have gotten back at her, but she warns them that next year, she won't go easy on them, especially on Lynn Sr. This causes the family to run away in terror, all while Luan laughs maniacally.
Lynn - Gets attacked by the monkey that took Lily's place.
Luan - Gets stuck to the motel sign, then gets a pie to the face, falls onto a fold-in bed that flings her into a bin of dirty laundry, gets launched into gelatin, gets sprayed on by a skunk, and floats up into the air by Lana and Lola's inflatable hazmat suit.
Lynn Sr. was the only one who didn't get pranked by Luan, because he was her partner in crime.
Lincoln and Lily's pranks actually turned out to be mess-free and somewhat harmless.
The main colors on the title card represent Luan's signature color (yellow), and the name of the episode is the color of her squirt flowers (hot pink).
This episode reveals that Lana is allergic to rhubarb.
This is the second time since "Overnight Success", that Lynn Sr. refers to Lynn as "Lynn Jr.".
This episode reveals that, like Lincoln, Lynn Sr. tends to come up with overly long names for his plans.
When Lana is saying a prayer for her pets, she mentions that she has an ant colony.
In the UK, Lucy's lines: "Please tell me this is not bleach" and "And it's bleach", were cut.
The Prank-Me-Not Poncho that was supposed to protect from Luan's pranks became a prank device used on Luan.
When Rita received the threatening voicemail from Luan, everyone screams, except for Lynn Sr. This foreshadows the fact that Lynn Sr. was aiding Luan.
Fool's Paradise - The title is a reference to the term of the same name, which is a state of happiness based on a person not knowing about, or denying the existence of potential trouble.
XYLØ - This episode title was a song title by a duo singer under the same name.
Evil Con Carne - There is also an episode of this show with the same name.
Vacancy - The plot is similar to the 2007 thriller-movie starred by Luke Wilson and Kate Beckinsale.
Saw - Lynn Sr. becomes an accomplice of Luan, which is similar to Amanda Young and Mark Hoffman from the films.
Kansas - Luna quotes the beginning lyrics of the chorus to the band's song, "Carry On Wayward Son", while falling into the gelatin trap.
This marks the second time Luna quoted this same song.
The first was in "Pets Peeved", when she said the third line of the chorus' lyric "Lay your weary head to rest".
Fearless - The epic Veigar Margeirsson song plays when Lincoln and Lynn Sr. devise a way to get back at Luan.
Psycho - The Buttz Motel, the setting of this episode, is a pun on the Bates Motel, the setting of this classic horror film.
It - The inflatable clown resembles the titular character from this Stephen King novel.
Futurama - At the beginning of the episode, Lisa suggests on putting Luan in a freezing chamber. The appearance of the chamber resembles the cryonic tube Fry fell into in the series pilot.
The Rugrats Movie - Luan switching Lily with the monkey is similar to the scene where Chuckie and the twins switch Dil with a baby monkey.
Total Drama - When Luan makes a joke and laughs evilly while the Loud Family screams in horror, music from the show plays and later when the Loud Family (minus Lisa) leaves the hotel room while Lincoln drops the cricket, music from the show plays.
Leni said she always gets "Nose Goes", the method of touching your nose to indicate you don't want to do something, wrong, but in "Suite and Sour" and "Potty Mouth", she got it right, and the one who lost in those episodes was Lincoln.
In "One Flu Over the Loud House", Lincoln claims that nobody in his family has a food allergy, but this episode reveals that Lana is allergic to rhubarb, when she was eating the rhubarb pies in the room she fell in.
He could have probably meant him and his surviving sisters: Lisa, Lucy, and Leni. Lana was already infected and it was too late for her.
After Lynn gave Luan her blue clown shoes, Leni gave Luan her sandals as a back-up pair, but when the family are at the motel, Leni has her sandals back.
Rita's eyelashes are disconnected from both of her eyes and for every split second, Lynn Sr.'s patches are both gone and back when he moves his arms up and down.
When Lana rams the room door with a janitorial cart, the "BROOMS" on the closet door is visible, despite the door being open.
When Luan is floating in the prank-proof suit and telling her family that they got her, her eyelashes are missing.
In the next shot, where she tells them she'll get them back next year, her eyelashes are back.
Lana noticed that her toolbox was missing when Vanzilla "broke down", but when she managed to shut down the electronics going haywire, she had her tool belt.
It remains a complete mystery as to who owns the Buttz Motel, and how Luan was given the right to infest it with traps.
It's unknown how Luan managed to hitch a ride beneath Vanzilla even though she left for "clown camp" and that Vanzilla had already left her behind.
When Leni is hanging from the motel sign, her eyelashes are disconnected from her eyes.
The family falling victim to Luan's pranks, and were being left behind, which they said that it's okay for them.
Lynn Sr. suggesting on places to hide.
The "Prank-Proof" hazmat suits (also known as the Prank-Me-Not Poncho) being worn by the Loud family.
The family coming up with plans to avoid Luan and her pranks.