Chapter Text
“Are you sure this is safe, professor?” a young man asked tentatively.
“Of course it’s safe!” someone else replied with a hearty chuckle. A strange laugh reverberated ominously along the laboratory walls. “I’ve tested it dozens of times. Hundreds of times, even!”
Luigi shifted anxiously. The chair he sat in was built in such a way as to lock his arms and legs into metal cuffs. All he could do to alleviate his nerves was shimmy the rest of his body around mindlessly. “B—but you never tested it on something alive. What if it explodes and kills me?”
From across the room, Professor Elvin Gadd laughed again. “Luigi, you worry too much. I would never subject you to this if I weren't certain you’d be fine.” He whirled around, a maniacal glint shining from behind his tinted lenses. “Now! Let’s not waste any more time, shall we?”
“O—okay.” Luigi gulped, bracing himself as the professor approached. The old man was holding a repurposed pasta strainer, outfitted with lights and plugs and coloured buttons. Blue and red wires protruded from every hole, looping in and out of the strange device. A steady but hollow beeping noise emanated from within the bowl.
Once Gadd was directly in front of Luigi, he placed the strainer atop the green plumber’s head. It sank comically over Luigi’s face, eliciting a frustrated whine. “It doesn’t even fit!”
“It doesn’t have to fit, my boy. It just has to stay on your head.” Gadd reached beneath Luigi’s chin, fumbling with the two straps that dangled by his ears. The buckles snapped together with a satisfying click. Gadd stepped away to admire his work, but not before pushing the strainer upright to ensure it didn’t cover Luigi’s pouting face. “Aaaaand... there. We’re all set!”
Luigi didn’t look quite as excited as the professor did. “Will it hurt?” he asked meekly, already looking rather defeated.
Gadd smiled, shaking his head. “Not one bit, I promise.” He shoved his hand into the pocket of his lab coat, feeling around for a moment or two, before fishing out a rectangular remote with only one large, red button. With no further fanfare, he pressed it eagerly, grinning from ear to ear.
Luigi flinched. The strainer on his head was beeping louder, more rapidly, and the lights started flashing on and off. The whole thing began to vibrate and buzz, and for a moment, Luigi convinced himself that his ears were about to bleed. He squeezed his eyes shut as the lights flashed faster, and the beeping grew ever shriller. The strainer vibrated even more violently, rattling Luigi’s brains around until his thoughts were nothing but a cacophony of terror and adrenaline.
And then it stopped. The smell of smoke permeated the air.
“No, no, no!” The professor dashed to Luigi’s chair, plucking the strainer away and flipping it around in his hands. “Darn it all! Poppycock! Absolute rubbish!”
Luigi groaned, shaking his head to chase away the pounding headache. “Wh—what happened?”
“A melted battery is what happened! It ruined the central wiring!” Gadd let out an angry huff, tossing the strainer onto a nearby table without a second thought. “I’ll have to redo it all... What a waste."
Hearing those words made Luigi look up at the professor hopefully. “...Does this mean I can go home?”
Gadd stared at Luigi for a moment, his face unreadable, and then he deflated. “Yes, you can go home,” he sighed. “Let me get you out of that thing.”
As the professor fiddled with the metal cuffs binding him down, Luigi wiggled his toes in anticipation. These tests usually took multiple hours, and getting to go home early was a welcome change. Maybe he’d have time to do some baking. Or perhaps he could catch an episode of his favourite soap opera. And if the night was still young, he could even do some gardening. The possibilities were endless!
Before he knew it, the cuffs snapped away from his limbs. Luigi carefully stood up, stretching his body and grinning widely. “Okay, I’ll see you later, professor.”
“Now, Luigi, before you go—“
“I’m going home now, Professor.”
Gadd blinked owlishly. “Y—yes, of course. I just have to—“
“Gottagetgoing! Bye!” Luigi waved gleefully behind him as he made a mad dash for the door. He wasn’t about to get wrapped into more mad experiments, no sir! Luigi was going home right that instant. The professor wasn’t about to rope him into doing anything else that night.
“But Luigi! Just a moment—“
“ARRIVEDERCI, PROFESSORE!!” Luigi hollered as he slammed the door open and bolted away.
Gadd gazed out the door Luigi left through, watching helplessly as the young plumber vanished into the cloak of the foggy night. “...Oh well,” he murmured with a shrug. “I tried.”
“You’re home early,” Mario commented as the front door swung open.
Luigi only nodded in reply. The younger brother flung his body onto the living room couch, snuggling into the blankets and humming contentedly.
“Don’t get too comfy,” Mario said with a smile. “I made dinner.”
“You did?” Luigi perked up, popping his head over the back cushion. “What did you make?”
“Pancakes and strawberries. I didn’t think you’d be home, so I packed yours in the fridge. You can eat it when you’re ready.”
Luigi hummed, smacking his lips. “Grazie, bro. I’ll eat in a bit. I’m just gonna—“ A gaping yawn cut him off. Luigi’s excitement had suddenly worn off; he began to feel dreary and worn out. “—sleep for a bit.”
Mario frowned, looking up from his empty plate. “Put on some pyjamas first. It’s not good to sleep in your overalls.”
“Okay.” Luigi dragged himself away from the couch, disappearing into the bedroom to change clothes. In the meantime, Mario busied himself with cleaning up his dishes, whistling a merry tune as he worked.
It was nice to have Luigi home early. The two often had conflicting schedules, especially on weekdays, so Mario always treasured the afternoons they could spend together. The elder brother briefly considered fetching some ice cream from the freezer and putting Luigi’s favourite TV show on.
But then a sickening thump sounded from the bedroom.
Mario flinched at the noise. Luigi tended to trip over his own feet sometimes. However, that sort of thing was usually followed up with a muttered curse, or Luigi awkwardly laughing at his own clumsiness.
“Luigi?” Mario called from the kitchen, unnerved by the sudden silence. “Are you okay in there?”
Luigi didn’t reply.
Mario shoved the dishes aside, making a beeline for their bedroom. Just as he feared, Luigi was sprawled out on the bedroom floor, limbs strewn in all directions. His pyjama shirt was only pulled on halfway, and his nightcap had fallen off during his collapse. The poor man wasn’t even moving.
Mario gasped, kneeling to the ground to help his brother stumble to his feet.
“B—bro,” Luigi breathed, swaying in Mario’s grip. He was conscious, at the very least, but unsteady and barely lucid. He swallowed thickly as he struggled to stay upright. “D—don’t feel good.”
Mario’s brows furrowed in worry. “Oh, cavalo… Come on, bro. Let’s get you into bed.”
Luigi nodded but didn’t move.
“...Luigi, come on. You have to walk with me.” Mario guided his brother to the bottom bunk, lifting Luigi’s legs and gently rolling him over until he was lying down. Mario pulled the comforter over Luigi’s trembling body, shushing him and whispering reassurances. “It’s okay, bro. You’re gonna be fine.”
“It hurts.” Luigi winced when Mario brushed his hand along his forehead. Way too hot. He must be running a fever. “I think... the professor... his machine. And that’s why... I don’t... feel good.”
“Professor Gadd?” Mario cocked his head. He wondered what the professor could have to do with Luigi’s sudden illness. And what’s this about a machine? “I’ll talk to him, alright? You just get some sleep.”
“Thanks, bro.” Luigi’s eyes fluttered to a close. “L—love you.”
Mario sighed, watching closely as Luigi gradually fell into a fitful sleep. “Love you too.”
When Luigi finally woke up, a new day’s sunlight was trickling from the window.
The young man groaned, his hand instinctively shooting to his forehead. God, he felt awful. His head was pounding painfully, his legs were numb and sore, and he was sweating like a hog. If it weren’t for the sunlight directly in his eyes, Luigi would have gladly gone right back to sleep.
But instead, Luigi grumbled and sat up straight, forcing himself to wake up. He’d have to venture downstairs for some medicine, maybe a cup of tea. With a heavy heart and a muttered complaint, Luigi clambered out of the blankets and rose to a stand.
The first order of business was to put on some clean clothes—preferably something that wasn’t drenched with his own sweat.
So Luigi meandered his way towards the closet, fumbling around for something to wear. Neither he nor Mario had anywhere to be that morning, so Luigi decided to wear something more comfortable. After rummaging through his clothes, he settled on setting aside a pale green turtleneck sweater, blue denim jeans, and—of course—his signature hat.
But as Luigi stripped down and began to change clothes, he noticed something strange.
His jeans, which fit perfectly fine last week, were now too small for him. He couldn’t even manage to slip his legs through the darned holes. Not only that, but as soon as Luigi finally stuffed his arms into his turtleneck sweater, the seams along the arms began to tear apart. He quickly took the shirt off before it was completely ripped up.
Worse yet, his poor hat wouldn’t even sit properly on his head! This was an outrage!
Needless to say, Luigi was confused. He began to pace around the room in his boxers, his ruined and ill-fitting clothes shoved into a corner. After some contemplation and failed attempts to put on overalls, a button-up, and a soccer jersey, Luigi put his remaining intact clothes back into the closet.
“Mario,” he called, unsure of what else to do. “Can you come here?”
“Sure thing!” Mario hollered from another room. Footsteps quickly clomped through the house, and Mario appeared in the doorway, relieved to see Luigi was awake. But then his expression morphed. His eyes widened, his eyebrows shot up, and he stepped backwards.
“Uh, bro?” Mario said quietly, “Did you… have a growth spurt?”
“I guess so!” Luigi spat in exasperation, throwing his hands into the air. “None of my clothes fit, everything hurts—oh, and I’m pretty sure I’m going to vomit.”
Mario cleared his throat, gathered himself and stepped into the threshold of the bedroom. “I mean, I know you’re taller than me, but this is ridiculous,” he joked half-heartedly. “You’ve sprouted, like, half a foot! Maybe we should get you on the basketball team.”
Luigi pouted, his lower lip quivering. “Not funny, bro.”
“Ah, scusi.” Mario had the decency to look sheepish. “So, um… the Princess and Professor Gadd are here. They’re in the living room.”
A startled, strangled noise erupted from Luigi’s throat. “O–oh, boy. I–I, uh...” He spun around, flustered at the thought of visitors seeing him like this—especially the Princess. “B–but only my pyjamas fit. I don’t have any other clothes.”
“They won’t mind.”
“But they… I don’t…” Luigi grasped the bridge of his nose, trying to mentally psych himself up. “Okay, okay, fine. I’ll be right there. Let me put my pyjamas back on.”
Mario nodded, making a brisk exit to return to the living room. Peach was seated in the corner nursing a cup of tea, while Gadd stood nearby with a mug of pitch-black coffee. They both gazed at Mario questioningly.
“He’ll be just a second,” Mario told them. “He’s just putting on clothes that fit.”
Peach cocked her head. “Clothes that fit?”
“Professor Gadd can tell you all about it,” Mario deadpanned, jutting his thumb toward the Professor. “He tested another weird machine on Luigi. Now he’s sick, and he’s way taller, too.”
The professor suddenly perked up, his eyes widening behind his glasses. “Luigi grew taller? Is that true?”
“Sí. We just noticed this morning.”
“That’s peculiar,” Peach murmured, stroking her thumb along the rim of her cup. “Professor, do you have any idea why this happened?”
“I most certainly do,” Gadd replied, downing a hearty swig of coffee before continuing. “Luigi helped me test a new invention of mine last night. I had a feeling this fever of his was a side effect, but I had no clue the machine actually worked.” He set his mug aside, folding his fingers together and resting them thoughtfully on his chin. “Mario, how much taller did Luigi grow by?”
“Seven inches,” someone replied.
Three heads whirled around at the new voice. Luigi was standing behind the hall corner, barely out of sight, as if he were afraid to come into the open. “I just measured it,” he muttered lowly, keeping himself partly hidden behind the wall. “I’m seven inches taller.”
“Incredible,” Gadd gasped. He clapped giddily, a huge grin crossing his wrinkled face. “Come in here, my boy! I must see it!”
“I–I don’t want to.”
Mario sighed. “Bro, it’s okay. They’re not going to judge you.”
“Yes, they are. And then Professor Gadd is gonna start poking me with measuring stuff.”
“No, he won’t,” Mario replied. He shot a pointed glare at the professor, who had the courtesy to look embarrassed. “Just come out.”
Luigi sighed miserably. He hesitantly sidestepped the nearby wall and into full view of the curious professor.
Mario blinked, taking in the full view of his brother standing awkwardly in the open. Sure enough, he’d sprouted up in height dramatically, enough so that Mario actually had to crane his neck to meet Luigi’s gaze.
“Amazing!” Gadd cried before Mario shot him a seething grimace. “Er, I mean… How unfortunate. This is awful.”
“Professor,” Peach sighed, looking rather disappointed as she nursed her teacup. “Do you remember what we discussed?”
Gadd coughed and looked away, his cheeks flushing. Based on his reaction, this wasn’t the first time he was verbally chastised by the princess. “…No testing inventions on live subjects.”
“You know better than to put Luigi in these situations. You’re taking advantage of his helpfulness.” The princess looked over at Luigi, her face crestfallen and her tone apologetic. “I’m so sorry about this, Luigi. The Professor is going to fix this for you. Immediately.”
Her final word was biting and venomous and was obviously directed at Gadd, who grumbled in reply.
“Yes, yes, I was just going to do that.” Gadd hopped off his chair and began meandering towards the door, abandoning his coffee mug on a nearby side table. “Come along, Luigi. Let’s get this sorted out.”
Luigi blinked, glancing between Gadd and Peach, before ducking his head and following the professor out the door. Mario and Peach silently watched them leave. The door clicked shut behind them.
Mario and Peach were silent for a minute.
“I think I’ll—”
“Perhaps you should—”
Mario cleared his throat and held his hand out, gesturing for Peach to speak first.
“I imagine Professor Gadd is planning to pester Luigi with more experiments,” Peach explained, eyeing the door he’d just walked out of. “You should make sure he stays on track.”
Mario’s face fell. “I was thinking the same thing. I’m so sorry, Principessa… I wanted to spend the morning with you.”
“I’m available all day, Mario. Just stop by the castle when you’re free again.” Peach stood up, brushing her skirt free of wrinkles. She turned and planted a brief, chaste kiss on Mario’s awaiting forehead. “Thank you very much for the coffee. It was lovely.”
“S—Sí, anytime,” Mario replied with a flustered cough.