With Luan locked in a cell in the basement, who is responsible for the April Fool's Day pranks this year?
Lincoln is hard at work patrolling the door to the basement. He explains to the viewers that today is April 1st, also known as April Fools' Day; the day Luan becomes a crazed maniac by relentlessly pranking her family. Wanting to ensure that she does not pull any pranks whatsoever, the family have gone the extra mile by securing Luan in a locked cellar in the basement a week beforehand. Going into the basement, Luan tells Lincoln that she has retired from April Fools pranks, saying she has grown up now. However, Lincoln refuses to listen, and after a petrified Lynn Sr. comes down with her lunch, Lincoln prepares to head back up. Suddenly, a salami on a string comes down and swings right into Lincoln's face. Lincoln accuses Luan of setting that up, but Luan tells him she did not do that because she is locked up. Suddenly, the house vibrates, and when Lincoln goes to check it out, he sees his family being mercilessly pranked by booby traps set all over the house. The family attempts to seek refuge in Lisa's underground bunker and the garage, but they too have been laced with pranks.
The family goes to confront Luan to tell her to stop with her pranks, but Luan tells them she is innocent, saying she retired from April Fools pranks. However, the family thinks she is lying and prepare to leave, but Lincoln realizes that the pranks that hit them are much different from Luan's usual ones, like how some of the materials that were used were only done during a specific time of their lives. Despite this detail, the family refuses to listen, and leave when Lincoln suggests letting Luan help them catch the real prankster. When Luan says she knows how a prankster would think, Lincoln decides to let her out under certain conditions.
After carrying Luan, wearing Lynn's hockey mask and tied to a dolly with Lynn's sweatbands, upstairs, they enter the bathroom, and discover that no one has entered yet. After agreeing to let Luan loose, Luan observes that the toilet was set to explode the next time it flushed, and that there is a tripwire connected to a tarp full of eggs. She also realizes that whoever set them haven't left any clues of their presence. Meanwhile, the rest of family is on a drive to get away from the madness, and decide to get something to eat at Burpin' Burger.
Arriving downstairs, Luan tells Lincoln to look at the couch. He sees Charles sipping a box of juice, and thinks it normal. Approaching the dog, Luan tells him to come down, when he suddenly responds with "No!" and can seemingly stand on two legs. When Lincoln points out that he has never seen Charles do that, Luan says it is not Charles, and after tackling him, she pulls off the mask to reveal Lily, the real prankster. Luan is admittedly surprised by this revelation, but she demands her to stop with her pranks. Lily refuses, and turns on the TV with her bone (which doubles as a remote), revealing the family driving in Vanzilla. At that moment, the family arrives to Burpin' Burger, and just before they can place their order, Rita gets a text from Luan saying that Lily is the prankster. As first, the family does not believe her, and when Lynn Sr. pinches on "Lily's" cheek, he inadvertently pulls off a mask to reveal Charles, much to the horror of the family. With the secret revealed, Lily activates her grand prank: she has the locks on Vanzilla lock the family in, and the car begins to drive around the Burpin' Burger building on an endless loop. Luan begs Lily to stop, but Lily lets out a fart cloud to escape.
Running upstairs, Lincoln and Luan discover that Lily fled to the attic. Upon entering the attic, they discover a console with numerous monitors showing the family screaming for their lives. At that moment, Lily arrives on her toy trike with a loaded diaper, ready to attack them. As Lincoln fights with Lily, Luan attempts to shut down the console and stop Vanzilla. After falling through the floorboards by a trap Lily set up, Luan uses a juice box to squirt juice onto the console, which successfully shuts it down and makes Vanzilla stop moving. Lily is initially disappointed her prank was foiled, but cheers up when Rita and Lynn Sr. vomit from all the motion.
Later that day, as the family sits in the living room, exhausted from everything they went through, Lincoln, Luan and Lily approach them. Rita declares that Lily is grounded until she is 16 years old (boosted to 21 after they get onion water dumped on them). However, Luan admits the onion water prank was hers, saying that because of Lily's actions, she feels reinvigorated and decides to come out of retirement. When Lily fist pumps with a "Yes!", Luan realizes that Lily deliberately pranked her family to motivate her to come out of retirement. Touched by this, Luan hugs her baby sister in gratitude, while Lynn Sr. realizes in horror that now, the family has somehow raised two pranksters.
This was the last episode on which Jared Morgan worked before his departure from Nickelodeon. According to Jared, he did two weeks worth of work on this episode at home due to the COVID-19 pandemic.
This is the first April Fool's Day episode to not have the word "fool" in the title.
It is also the first April Fools episode to not be written by both Sammie Crowley and Whitney Wetta, as Sammie left Nickelodeon in 2019 to work at Disney, as well as the first April Fools episode to not be boarded by Miguel Puga, as he now works on The Casagrandes.
This is the April Fool's episode that aired closest to the actual holiday, premiering six days before the actual date.
This episode takes place after "Fool Me Twice", as Luan tells her family that she has retired from April Fools pranks, having taken her promise of never pranking her family again from the aforementioned episode to heart.
Due to Lily's deliberate pranking, however, that promise may officially be broken.
Coincidentally, the title card bears a resemblance to that of "Fool Me Twice".
Lincoln brings up the events of "April Fools Rules" by stating that locking Luan up a day before proved unsuccessful, so they opted to lock her up a week before.
Another reference is where Rita and Lynn Sr. hide inside Lisa's Underground Bunker to avoid the pranks made by one person; in Silence of the Luans, it is Lily, but in April Fools Rules, it is Luan.
In the Hebrew dub, this episode shares its title with "April Fools Rules".
Lincoln only playing the audio of 'the Mass Hairwaxing Disaster' could be in response to U.K. airings of "April Fools Rules" omitting a scene in which Luan shaves her family's pets.
Lynn Sr. has been traumatized by Luan's April Fools antics so much, he sometimes cannot speak properly, resorting to him babbling his dialogue (which his wife can translate).
There are some subtle hints that foreshadow Lily and Charles having switched places:
When the family leaves in Vanzilla, "Lily" has a blank-faced expression, sits in a peculiar position, and the stitching around the wrists is visible.
When Lincoln and Luan see "Charles" in the living room, he's capable of sitting and standing like a normal person, and at one point, says "No!"
Lily was not seen when the family confronts Luan in the basement.
One hint towards Lily being the secret prankster was that the tarp used in the tripwire-egg trap was her blanket.
Due to her absence at college, Lori ends up being the only member of the core Loud family to not get pranked.
Despite this, she does appear in a flashback getting pranked at the beginning of the episode.
It is revealed that when Luan is very thirsty, her voice becomes raspy, and she has to cough to get her voice back to normal.
It's revealed that Luan originally used fresh whip cream for her pranks when she was younger but stopped around the time the twins were born and currently uses spoiled products to attract animals.
Luan, a prankster known for thinking several steps ahead of her targets, is foiled by Lily setting a trap in the attic, and even remarks that she should have seen that coming.
While disguised as Charles, Lily gave herself away by sitting normally on the couch, drinking from a juice box and yelling "No!" at Luan, making her disguise pointless.
When Lincoln suggests letting Luan out of her cell to help find the real prankster, Rita coldly states that she and the others will "leave his room untouched as a memorial," implying he would not survive if he fell victim to one of Luan's pranks.
One of the pranks Lily set involved the toilet shooting out a geyser of water which would have the victim jetted from the toilet while using it.
Cartoon physics: Luan flooded the entire house with mustard and even sent it floating down a river.
Silence of the Luans - The title and premise of this episode references the 1991 psychological horror film The Silence of the Lambs. At one point, Luan wears a face mask and a straightjacket while being carried by a dolly, resembling the attire of Hannibal Lecter.
Saving Private Ryan - The way Lincoln sees his family getting pranked in slow-motion while dazed is similar to the opening of this 1998 war film.
Kalamazoo River - One of Luan's previous pranks involves sending the Loud House down this Michigan river, which gained in notoriety in 2010 when it became the site of a disastrous oil spill.
Titanic - The scene of Rita and Lynn Sr. laying on their bed while their room is flooded with water is identical to the elderly couple dying together on their bed in this 1997 film.
In Polish dub, sound isn't synchronized with picture.
When Lily is unmasked, her hair clips through her Charles mask in one frame.
When Lily makes an angry face, her eyelashes are missing at points.
When Luan falls down from the attic, her ponytail disappears, leaving a brown spot.
In Vanzilla, Luna is sitting between Leni and Lucy. But when the family is seen through the monitors in the attic, Leni and Lucy are next to each other.
It is unknown how Lincoln had time to change his dirty clothes.
Possible: Lily attacks Luan and Lincoln with a diaper, even though she is potty-trained now. Though, she could have deliberately soiled it with the intention of using it as a weapon.
The Great Mustarding is said to have been three years ago. However, in the flashback, the characters look the same age as in the present.
Possible: Even though Lily was revealed to be the prankster, the family never apologized to Luan for assuming it was her. However, they might have done that later.