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Donnie hated being sick.
It was messy, inefficient, and worst of all—it made him weak. His head throbbed, his throat burned, and every sound seemed ten times louder than it should’ve been.
And Leo, of course, was being Leo.
The blue twin’s laughter echoed down the hall, lighthearted and bright, cutting through Donnie’s pounding headache like a blade.
“Leo, for the love of the cosmos—could you not be so loud?!” Donnie snapped, voice cracking mid-sentence.
Leo froze mid-spin, his grin faltering. “Whoa, easy there, Dee. Didn’t realize my charm had volume control.”
That did it. Donnie glared, muttered something incomprehensible under his breath, and stormed off toward his room, his robe swishing behind him.
The moment the door shut, all the fire drained out of him. His legs trembled as he stumbled to his bed and collapsed face-first into the pillow. He felt awful—physically, emotionally, cosmically awful. He’d yelled at his twin, the one person who always put up with him no matter what.
Tears burned at the corners of his eyes as his breath hitched. His fever made everything foggy, and his guilt made it worse. “I didn’t mean to yell…” he mumbled to himself, voice muffled by the blanket.
Meanwhile, in the living room, Leo blinked at the closed door before sighing.
He knew that tone. That sharp, snappy tone Donnie got when he was trying not to show he was miserable.
“Poor guy,” Leo murmured. “He’s sick, isn’t he?”
It didn’t take him long to act.
Within minutes, Leo was in the kitchen, stirring up Donnie’s favorite hot soup—simple, comforting, and easy to keep down. He grabbed the soft blue blanket that Donnie always loved (though his twin would never admit it out loud) and padded quietly toward Donnie’s room.
He pushed the door open slowly. “Dee?” he whispered.
The sight hit him right in the chest.
Donnie sat on the bed, trembling slightly, eyes red and glassy with tears. His mask tails drooped, his face flushed with fever and streaked with sweat. He looked small—fragile, even—and Leo’s heart squeezed.
“Oh, Dee…”
He crossed the room, setting the bowl on the bedside table. “Hey, baby. I brought you some soup. And your favorite blue blanket that you always like to steal from me”
Donnie lifted his head, eyes wide and watery. His voice came out weak and broken. “Nardo…? You—you’re not mad at me?”
Leo’s expression softened. He sat on the edge of the bed, draping the blanket gently around Donnie’s shoulders. “Mad? Nah. You were sick, cranky, and yelling is basically your fever language. I get it.”
Donnie sniffled, his bottom lip trembling. “I’m s-sowwie for relling at you, Reo…”
Leo’s grin returned, warm and teasing. “I gotcha, baby.”
He picked up the spoon, blew on it gently, and held it out. “Open up.”
Donnie hesitated, then leaned forward to sip. The warmth slid down his throat, easing some of the ache in his chest. He sighed softly, a pitiful little chirp escaping before he could stop it.
Leo chuckled. “You’re sweet and cute when you’re so miserable.”
“...I wuv you,” Donnie mumbled through his congestion, eyes heavy with exhaustion.
Leo’s smile turned soft. He chirped back gently, “Love you too, Dee.”
He kept feeding him until Donnie couldn’t take another bite. Then he set the bowl aside, helped him sit back, and offered the medicine. Donnie took it without complaint—a sure sign he was really sick as Donnie would usually fight him when it came to taking medication.
“Good job, my little genius,” Leo said quietly, fluffing Donnie’s pillows and tucking the blanket snugly around him. “Now rest, okay? If you need anything, call me.”
Donnie nodded sluggishly, his eyes already closing. “Thanks, Nardo… love you…”
Leo’s throat tightened. He leaned down, pressing a soft kiss to the top of Donnie’s head. “Love you too, little bro.”
He stood for a moment, watching as Donnie’s breathing evened out and the tension finally left his face.
“Sweet dreams, Dee,” Leo whispered as he turned off the light. “I’ll be back later.”
He slipped out quietly, closing the door behind him—leaving the room filled with the faint sound of Donnie’s soft chirps, comforted and safe under the blue blanket that smelled just like his older twin.
.
.
.
The lair was quiet. For once, Leo found himself enjoying the rare peace — no explosions from Donnie’s lab, no chaotic shouting matches between his brothers, just the faint hum of the city above.
He’d been checking on Donnie every hour or so, peeking into the room to make sure his twin was still resting peacefully. The last time he looked, Donnie had been fast asleep, his fevered face pressed into the blue blanket, a small chirp slipping out every now and then. Leo had smiled and slipped away.
Now, an hour later, his phone buzzed on the table.
A message.
From Donnie.
Dee: Nardo... come here... please...
Leo’s stomach dropped. There was something about those few words — the broken phrasing, the “please” — that sent pure panic rushing through him.
He didn’t hesitate.
He sprinted down the hall, nearly tripping over one of Mikey’s abandoned toys before bursting into Donnie’s room.
“Dee—?”
His heart clenched.
Donnie was curled up in the center of his bed, shaking violently under his blanket. His face was pale except for the angry flush on his cheeks, and sweat dripped down his temples. Tears streamed freely from his eyes as he whimpered, his breathing ragged and fast.
“Nardo…” Donnie’s voice cracked painfully, hoarse and weak. “I—I saw you… you were gone— I couldn’t—” He choked on a sob, clutching his chest as his throat gave out mid-word.
Leo was at his side in an instant, kneeling beside the bed and gently grabbing his shoulders. “Hey, hey, shh… it’s okay, I’m right here. I’m here, Dee.”
Donnie gasped out another sob, reaching forward with trembling hands to cling to Leo’s arm. His chirps were broken, distressed — the kind that hit Leo right in the heart.
Leo pressed his hand against Donnie’s forehead and winced. “Shells, Dee… you’re burning up.”
He grabbed the thermometer from the bedside table, taking Donnie’s temperature with practiced care. When the reading blinked, Leo’s jaw tightened. It was higher than before.
“I’ll be right back, okay?” he whispered softly, brushing the back of his fingers against Donnie’s cheek.
Donnie shook his head weakly, eyes wide and glassy. “No… please… don’t go…”
Leo’s heart cracked at the desperation in his twin’s voice. He squeezed Donnie’s hand gently. “I’ll be fast, I promise. Gotta grab a few things to help you feel better. Just hang on, Dee.”
Donnie whimpered as Leo reluctantly slipped out the door.
Leo flew down the hall, practically skidding into the kitchen.
“Mikey!” he shouted. “Need more soup—stat!”
Mikey blinked from where he was half-asleep at the counter but immediately went into action. “You got it, bro!”
Leo grabbed medicine, a cold compress pack, and a clean towel, juggling them as Mikey handed over the hot bowl of soup.
“Thanks, Miguel. You are an angel,” Leo said breathlessly before dashing back toward Donnie’s room.
When he returned, Donnie was still curled up, his chirps weaker now, fading into soft, pitiful sounds.
“Hey, I’m back,” Leo said, voice gentle but firm as he set everything down. “Told ya I’d be fast.”
Donnie’s watery eyes flicked open, relief washing over his face.
“Okay, little bro,” Leo murmured, lifting Donnie’s head just enough to help him sit up against the pillows. “Let’s get you sorted.”
He coaxed Donnie through taking the medicine, whispering encouragements with every swallow. Donnie grimaced, the bitter taste making him wrinkle his nose, but he obeyed without a word — too tired to fight.
Then came the soup.
Leo took the spoon, cooling each bite before bringing it to Donnie’s lips. “Come on, Dee. Half the bowl, at least. Doctor’s orders.”
Donnie tried to argue, mumbling something weakly about data efficiency and discomfort, but the next second, a miserable chirp slipped out that shattered Leo’s composure.
“Yeah, I know,” Leo whispered, voice thick with emotion. “I know, baby. Just a little more.”
By the time Donnie finished half the bowl, his eyelids drooped, and his body sagged against Leo’s shoulder. Leo set the dish aside and pressed the cold compress gently to Donnie’s forehead.
“Better,” he murmured, brushing a few damp mask tails away from Donnie’s face. “That’ll help.”
He stood to rinse the towel — but then Donnie’s weak hand shot out, gripping his fingers tightly.
“Nardo…” Donnie’s voice was barely a whisper. “Don’t… leave me. Please.”
Leo froze. His twin’s eyes were wide and glassy, trembling lips pressed together like he was trying not to cry again.
Leo smiled softly and sat right back down, pulling Donnie’s hand into his own. “I’m not going anywhere, Dee. I’ll stay right here, okay?”
Donnie sighed shakily, the tension melting out of his shoulders. He curled closer, resting his head against Leo’s plastron, his breathing evening out as the fever fog pulled him toward sleep.
“Thank you, Leo…” he murmured, voice muffled. “You’re… too good to me… I don’t deserve you…”
Leo’s heart ached, and he leaned down to press a gentle kiss to Donnie’s cheek. “Hey, don’t ever say that. You’re my baby twin. Taking care of you is the easiest thing in the world.”
Donnie’s breathing hitched once before settling again. “...Love you, Nardo…” he mumbled sleepily.
Leo smiled, eyes soft as he brushed a hand over Donnie’s shell. “Love you too, Dee.”
He stayed there long after Donnie fell asleep, his fingers tracing idle patterns across his twin’s shell as he watched the slow, steady rise and fall of his chest.
“Get better soon, genius,” Leo whispered into the quiet room. “I’ve got you.”
.
.
.
The next morning came quietly, sunlight filtering faintly through the cracks in the lair’s walls. Donnie stirred under the weight of his favorite blue blanket, blinking groggily as his vision focused. His head still felt heavy, his throat still a little raw—but the ache had dulled. The feverish fog that had clouded his mind the day before was finally beginning to lift.
For the first time in what felt like forever, he didn’t feel completely miserable. Just… tired.
He shifted slightly and froze when he noticed someone slumped beside his bed, chin resting on crossed arms.
Leo.
The blue twin’s mask tails were slightly tangled, and there was a faint crease on his cheek where he’d clearly fallen asleep leaning against the mattress. His hand was still resting lightly on Donnie’s shell, as if he’d kept it there all night to reassure himself that Donnie was still breathing.
A quiet wave of warmth spread through Donnie’s chest. He hated being sick — but even he couldn’t deny how safe he felt knowing Leo was there.
“Nardo…” Donnie’s voice came out hoarse and raspy.
Leo stirred immediately, blinking the sleep from his eyes before lifting his head. When he saw Donnie awake and looking at him, a bright, relieved grin spread across his face.
“Morning, Dee,” Leo said softly, stretching before leaning closer. “How’re we feeling today?”
Donnie rubbed at his eyes and mumbled, “Still a little bleh… but not as bad as yesterday.”
Leo’s grin widened. “Good. Fever’s down too—see?” He placed the back of his hand gently against Donnie’s forehead, nodding in approval. “You’re not boiling alive anymore. Major win.”
Donnie couldn’t help but chuckle weakly. “Guess your care plan worked, Dr. Leo.”
“Of course it did,” Leo said smugly, then his tone softened. “I’m just glad you’re okay.”
Donnie glanced away, pulling the blanket up a little higher around his shoulders. “I… um… about yesterday,” he began, voice hesitant. “I’m sorry you had to—uh—deal with me like that. I must’ve been awful to take care of.”
Leo frowned slightly. “Dee—”
“I mean,” Donnie rushed on, his cheeks heating, “you had to feed me soup, for crying out loud. Like I was a toddler. It’s humiliating.”
Leo cut him off with a raised hand and a gentle look. “Donnie. Stop.”
Donnie blinked, startled into silence.
Leo smiled softly. “You don’t need to apologize for being sick. And taking care of you wasn’t some chore, okay? You’re my little brother—my baby twin. It’s literally my job to make sure you’re not miserable and alone.”
Donnie opened his mouth, but Leo continued before he could argue.
“If I had to do it a hundred more times, I would. No question. You’d do the same for me.”
That quiet sincerity in Leo’s voice made something twist in Donnie’s chest. He looked down, the faintest smile tugging at his lips. “You’re ridiculous,” he murmured softly, “but… thank you. For everything.”
Leo shrugged, his trademark grin returning. “No problem, genius. Though I do recommend resting another day. Gotta make sure that supercomputer brain of yours doesn’t overheat again.”
Donnie rolled his eyes, but there was no real bite to it. “Fine. Rest day it is.” He hesitated, fiddling with the edge of his blanket. “Um… would you maybe… stay with me? Y’know, help me rest?”
Leo blinked, then his expression softened completely. He grinned, gentle and fond. “I’ll do anything for you, Dee.”
Donnie felt his face flush again, but this time, it was from something warm and good. “Thanks, Nardo.”
The day passed slowly, comfortably. Leo brought snacks (courtesy of Mikey), queued up a few of Donnie’s favorite documentaries, and even let Donnie ramble about data patterns between naps. Occasionally, Leo would make a joke just to get his twin to roll his eyes — and each time, Donnie’s chirps came a little stronger, his smiles a little brighter.
By the afternoon, they’d settled into an easy rhythm: Donnie half-asleep against Leo’s shoulder, Leo absentmindedly tracing circles on Donnie’s shell. The hum of the lair filled the quiet between them — soft, steady, and peaceful.
Donnie sighed contently, voice barely above a whisper. “You’re… a good brother, Leo. A-a good twin”
Leo smiled and nudged him gently. “Yeah, well… I learned from the best.”
Donnie gave a small, tired laugh before murmuring, “Love you.”
Leo’s grin softened into something fond and real. “Love you too, Dee.”
And as Donnie drifted back to sleep — no fever, no tears, just peace — Leo leaned back, closing his eyes, grateful for the simple joy of having his twin safe and healing beside him.