At the Magic and Mystery Museum, Hypno-Potamus was enjoying a cup of tea while the brainwashed Luan juggled for his amusement.

"You won't get away with this, Hypno!" Dana cried out. She was locked inside a reinforced magician's zig zag box. And Hypno had already divided her into three pieces!

"Oh, but I already have, Lov." The mutant hippo mused. "Those blasted turtles will fall right into my trap."

"Not before I warn them first you big, fat-" Dana was cut off when Luan threw a pie at the mutant's face.

Hypno laughed and applauded. "Brava! We make an excellent team, Lu- er, I mean, Calamity Clown!"

"Yes, Master." Luan droned.

As Hypno-Potamus laughed in his throat, the wall suddenly blew up and the turtles stormed in. "Alright, Hypno! Hand over Dana and Luan! Or we're gonna make you disappear!" said Raph.

"Good line! Gotta remember that!" Leo credited.

Hypno-Potamus set down his teacup and stood. "Ah, turtles. So glad to could come! Welcome to my show!" He took out his razor-sharp magician hoops. "Calamity Clown! Attack!" And the villains sprung out, ready to fight.

"Let's get 'em, boys!" The turtles were ready to pounce, but for some reason, they didn't! They looked down and saw their feet stuck to the floor!

Hypno stopped charging and laughed at the trapped turtles. "April Fool's!"

Calamity Clown took out a remote and pressed the red button. The turtles screamed when the floor electrocuted them.

"Too easy! But then again, it doesn't take much to fool you turtles!" Hypno patted his brainwashed slave on the head. "Excellent job, my little jester!" The two approached the fallen ninjas. "Now, then...what do to with these little monsters? I could sell them to a freak show or perhaps that Baron Draxum fellow, a raging warrior scientist must be tapping some big bucks. Hmmm..." He turned to Luan. "What do you think Calamity Clown?"

The mesmerized Luan said nothing.

"Of course! Make the turtles my slaves! Excellent idea, Calamity Clown!" Hypno-Potamus took a deep breath, about to hypnotize the turtles with his voice. "MESME-"

"SHADDAP!" A female voice yelled before a foot kicked Hypno in the back of the head. He crashed into a pile crates filled with pranks supplies.

"What the-?!" Hypno removed a whoopee cushion off his head and gasped seeing Dana out of her boxes in one piece. But she wasn't alone. There was also ten other children with her as well. "What's going on here?! Who are you lot?!"

"We're the Loud family! And we're here to take back our sister Luan!" said Lincoln.

"AND PAYBACK FOR THROWING A BRICK AT MY HEAD!" Lori screamed. Her head was banaged like a mummy's.

"It was simple removing Dana from a cheap magician trick." said Lisa.

"CHEAP TRICK?!" Hypno-Potamus roared. He stomped to his feet. "I'll saw you in half and then we'll see if THAT'S a cheap trick!"

The turtles jumped in the hippo's way. Leo drew his sword out. "This is between us, Hypno! Leave the kids out of it!"

"Don't have to get me hands dirty with those brats." Hypno threw his rings at the turtles. "Calamity Clown! Get the bat!"

"Yes, Master." As the turtles fought with Hypno, Luan took out a seltzer bottle and sprayed a green liquid at Dana. Dana and the Louds dodged in time. They gasped with horror when the green liquid melted through the floor.

"It's acid!" Dana yelled. "You guys gotta get outta here!" She dodged another blast from Luan.

"Not without our sister!" Lori said. "Okay, guys! Operation Comedy Relief is a go!"

The Louds scattered as Dana dodged Luan's attacks.

"Hey, Lola! Knock, knock!" Lincoln said, making sure he wad loud enough for Luan to hear.

"Who's there, Lincoln?" Lola said very loudly.

"Amous!"

"Amous who?"

"A mosquito just bit me!"

Luan suddenly stopped. Her face was blank as her mind registered the joke.

"Keep going!" said Lori.

"Knock, knock!" said Lincoln.

"Who's there?" asked Lola.

"Andy."

"Andy who?"

"And he just bit me again!"

Luan started to crack a smile. She chuckled a little.

"Dudes! It's working!" said Luna. "More jokes!"

"Lucy! What did the skeleton say when he heard a joke?" asked Lynn.

Lucy shrugged. "I don't know, Lynn. What?"

"That was pretty humerus!" Lynn laughed, pointing at her leg. "Get it?"

Luan dropped the seltzer bottle. Her laugh became louder.

"Keep going!" Lori said, hiding behind a crate.

"What are you guys doing?!" Dana asked as she dodged another attack from Luan.

"Hypnotism is a powerful induction of one's state of consciousness. But not strong enough to overcome one's inner nature!" said Lisa. "Luna! Why did the guitar go to the music store?"

"Cause he was out of tunes!" Luna joked.

Luna dropped the seltzer bottle and laughed some more!

"Oh, no ya don't!" Hypno-Potamus roared. He took out a magician's hat and made an army of rabid rabbits pop out of the hat. Dana and the Loud siblings were pinned down by the rabbits. "DESTROY THEM!"

Luan returned to her trance. She took out a large hammer and heaved it high above her head.

"WILL YOU SHUT UP?!" Raph roared before punching Hypno-Potamus with his smash jutsu. The hippo crashed through a wall and was knocked out cold. "There! That should do it!"

"No, Raph!" said Leo, pointing at Luan. "She's still hypnotized!"

"LUAN! SNAP OUT OF IT!" Lincoln pleaded.

Lily started to cry. She cried and cried and cried.

"Huh?" Luan froze as the baby cried. Her mind replayed the many times when Lily cried and Luan was able to cheer her up with her jokes and comedy routines. "Lily?" She dropped the hammer and rubbed her eyes, groaning. "Guys?" She looked around. "Where am I? What's going on?"

"COWABUNGAAAAAAA!"

Luan was sucker-punched by Raph right across the face. The joking sister was sent hurling into a pile of crates.

The Louds gasped in shock as Raph dusted his hands. "There! That oughta snap her outta it!"

"Uh, Raph." said Lori. "Luan did snap out of it. You didn't have to punch her."

Raph blinked. "Oh...right."

Donnie and Lisa sighed in unison. "We'll get the medical equipment ready."

When Luan woke up, she found herself in Lisa's room. "Huh? I'm home?" When her vision cleared, she saw her parents and her siblings looking back at her.

"Luan! Oh, thank goodness you're alright!" Rita kissed her daughter on the forehead.

"Please don't move, Sibling!" Lisa warned. "You've suffered a severe concussion. You've been out for two days!"

"Two days?!" Luan yelped before she moaned from the pain of her throbbing head. "What happened?! The last thing I remember was a green and red truck running into me!"

Lincoln blinked. "Um, that wasn't a truck." He took a deep breath. "You might want to brace yourself for this." He walked over to the doorway and motioned someone to come in.

Leo, Donnie, Raph, Mikey and Dana walked in.

"AAAAHHHH!" Luan was scared right out of the bed. Luckily, Lynn caught Luan in her arms before she hit the floor. She gently set Luan on her feet.

"You see, Luan. There was this mutant hippo who hypnotized you into being his slave and pull crime-realted pranks all over town!" Lori explained. She took out her phone and showed Luan the news footage of Luan's Calamity Clown crime spree.

Luan was aghast. "I don't believe it! I did all that?!"

"Heck yes you did!" said Leni. "Thank goodness we hired the turtles to be our bodyguards or we wouldn't have a chance of getting you back!"

"How'd you get mixed up with that freak anyway?" asked Lynn.

Luan looked away in shame. "Well, Ron was a fan of my comedy show. When he told me he was a magician and good at special effects, I thought he could help me prank you guys on April Fool's Day...but he came into the house and hypnotized me!"

"Well, I hope you learned your lesson, Luan." said Lincoln. "Whether they're a fan or not, you need to be more choosy about who you get involved with, especially online."

"Trust me, I've learned my lesson." Luan said. "In fact...I don't even have a joke about it!"

The Louds gasped.

"Wow! That's literally a first!" said Lori.

"Guess Raph broke your face and your funny bone!" Leo joked.

Luan laughed her famous laugh. "That's a good one! What's your name?"

"Leonardo! Huge fan of your comedy channel!" said the turtle in blue. "Maybe when your head's all better, we can do a show together!"

"Sounds good to me!" said Luan.

Lynn Sr. and Rita came into the room. "Kids! Dinner's ready!" said Lynn. He looked at the mutant bat and mutant turtles. "Guys, don't you want to take off those costumes already? I made lasagna as thanks for protecting us!"

"Costumes?" said Luan, Lincoln gave her a nudge and shook his head, silently telling his sister not to reveal to their parents that the mutants were real.

"Um, we'd love to, Mr. Loud." said Leo. "But..." He started pulling om his face. "We've been so hot in these suits that they won't come off!"

"But we can still eat." said Donnie. "Been a while since I've had an Italian food besides pizza!"

"Oh, you guys are gonna love Dad's lasagna!" Lana said. "To the dining room!"

"Lasagna? I don't know..." Raph tapped his chin.

"Come on, Raph! Lasagna is just like pizza, but in pasta form!" said Mikey.

Raph licked his lips. "Well, when you put it that way, let's get down and pig out!"

Everyone took off to dine, but Lincoln and Lily stayed behind with Luan.

"Are you going to be okay?" Lincoln asked Luan. "You should still lie in bed. Raph nailed you pretty hard..."

Luan rubbed her head. "I think I'm good. That's the downside of comedy, Lincoln. You always take a punch when folks don't get the joke. But I'll always keep bringing on the punch lines!" She laughed.

Lincoln laughed too. "It's good to have you back, Luan." He went downstairs to join his family.

Luan heard Lily cooing. She looked down and saw the baby wanting to be picked up by her older sister. Luan smiled as she picked up her infant sibling. "And it's good to be back." She kissed Lily's cheek and headed downstairs for some Loud family lasagna.