Donnie squinted over his test tubes as he slowly added his next chemical into the beaker on the bunsen burner. Could this be it? Could he finally have discovered the holy grail of all medicines? He had to be careful at this part. At an agonizing pace, he carefully added a drop of his chemical composition to the slightly boiling mutagen. Instantly, the beaker reacted and froze; the entire mixture seemed to freeze into a crystal of ice with how cold it became. Groaning, Donnie quickly wrote down "FAIL" in his notebook before reaching for his long metal tongs. He was sure touching the newly formed ice with bare flesh was a good idea. Disposing of it in his bio waste bin, along with the remaining chemical composition, Donnie took a seat at his desk and rubbed his temples. Finding this retro mutagen was irritating. He hadn't had time for really anything he considered fun. Not being able to work on his own inventions was really starting to catch up with him, along with the late nights of no sleep and barely eating his needed meals. Though after the most recent run in with the run a muck squirrel mutants, that almost cost everyone their life, he was more determined than ever.

A small knock on the door sounded, jumping the turtle from his thoughts. The time read 12:24 in the morning. Who, aside from him, would be awake at this hour? Rising from his seat, he expected it to be Leo or Sensei, ready to force him to bed. What he didn't expect was to see the color orange behind his door.

"Mikey?" Donnie couldn't help the confused expression. "What are you doing up this late?" Mikey's eyes were looking at the floor, as he seemed to refuse to look at his older brother. Donnie felt concerned as he stood aside a bit before inviting his brother in. "Come in for a bit."

Mikey didn't look up at him, but moved in sluggish movements as he went into the lab. Donnie's worry only began to grow. Even in the middle of the night, Mikey never moved slowly. Donnie closed the door and walked past Mikey, pulling up a spare chair for his brother. Mikey sat in it, and Donnie sat across from him.

"... Mikey, what's going on?" Donnie watched as suddenly Mikey's shoulders started trembling. Reaching out for the younger brother, Donnie jumped back when Mikey finally looked up. Tears were welling up in his eyes and his face was red from embarrassment.

"Mikey..." Donnie said softly before pulling Mikey to his chest. The youngest instantly wrapped his arms around him, sobbing into his brother. It was no secret that, if something had really bothered Mikey, he would seek out the smart turtle. Well, there was the one time with his Shredder nightmares, but Donnie, Leo, and Raph had quickly cured Mikey of that. Though here, the smart turtle was left alone. Not that he minded really; it was nice to see his only little brother still needed him. Donnie began gently shushing Mikey, knowing that it calmed the younger turtle down when he would murmur calming words into his ears. Subconsciously, he found himself rocking the turtle back and forth, desperately trying to get Mikey to stop crying.

"Shhh... It'll be okay," Donnie offered as he rubbed his baby brother's shell. He wasn't sure what was going on with Mikey, but the one thing he did know was that no matter what it was, he would correct it. Period. Mikey nodded against his chest, his cries beginning to subside a bit. "Just calm down, and tell me what happened."

Mikey sniffled and hiccuped, his sobs finally starting to go away. Not looking up to see Donnie, he started speaking finally.

"It... It was the Squirrelinoids," he hiccuped. "I can't get them out of my head, D. I tried but I'm starting to have nightmares. R... Raph was snoring loud, and Leo was asleep, and Sensei hates when we are out of bed late and I saw that your light in the lab was on and-"

"Shh shh shh shh shh," Donnie cooed gently. "It's okay Mikey. I don't mind, seriously."

Deciding that the chairs weren't a comfortable spot, Donnie gently pushed Mikey back a bit and offered a smile. Mikey sniffled, a little upset that had lost the contact from his brother; Donnie couldn't deny how cute Mikey looked when he was looking for more hugs. Donnie rose from his seat, gently pulling at his brother's arms in a silent motion for him to follow. Donnie pulled the younger turtle to a corner of the lab that housed a bean bag chair and a bookcase, where the smart turtle loved to read his books away from the noises of the lair. Mikey was confused when Donnie picked up the bean bag and tossed it to the side. The smart turtle then set himself up into the spot with his back against the wall and pat the floor in front of him. With sniffles still present, Mikey crawled to the floor and leaned his shell against Donnie's chest. Donnie wrapped his legs loosely around the younger turtle before wrapping his arms around his waist. Mikey reacted by holding onto his brother's arms, happy to be back into that contact again. Donnie couldn't help but grin. They used to snuggle like this when they were little. It soothed Mikey when they were just tots, so he figured this would be more comfortable for both of them, while making sure they could talk alone.

"When did the nightmares start?" Donnie asked softly.

"They started the night of the squirrel problem," Mikey sighed. "But I thought it would go away. It's only been a few days, and I know we all went through it. But I feel so scared. I can still feel that one gripping me with it's tongue and trying to drag me down the drain with it," this prompted a shudder from the young turtle. Donnie sighed, upset to see his young brother in distress. He squeezed a little tighter, securing Mikey to the here and now.

"I see," the smart turtle replied. "Well, you know we flushed those suckers down the drain. They won't be coming back."

"But what if they do, D?" Mikey turned his head to look at his brother.

"Then do you really think any of us would let them hurt you?"

"... No..."

"There you go. Simple logic," Donnie giggled. Mikey turned back and leaned his head on his brother's shoulder, not helping the small smile that spread over his face. "You're safe now, brother."

Mikey sighed as they just laid like that with each other, not caring if someone tried to barge in uninvited. He lost himself in his brother's embrace as even on the floor Donnie started to rock him a little bit. Relief began to wash over him, and he knew his brother wasn't judging him. A thought crossed his mind, remembering the last time he a cried to his brothers. It was embarrassing to be caught from the night terror that had gripped him. But it was more embarrassing what they had learned about him. Though the embarrassment of his brothers finding out he enjoyed being tickled was mostly gone, Mikey couldn't help but remember what Donnie had told him when they had all formed a mini slumber party in his bedroom.

"Next time you want to be tickled, just ask."

Mikey didn't know how much he had dared to ask. He knew Donnie had been so busy with is retro-mutagin, and he didn't want to bother him. But on the other hand, he knew he wasn't able to go back to sleep yet. Mikey let out an exasperated sigh, alerting Donnie to the mental turmoil.

"Mikey?"

Mikey mentally cursed at how loud his sigh ended up being. "I'm just thinking."

"What about?" Donnie was concerned. His brother had calmed quite a bit, but he could still sense something on the younger one's mind. Mikey silently gulped, knowing he would have to answer his brother.

"I... I was wondering if you could do something for me... and it stay between us?"

Donnie cocked his brow a bit at the question. "What is it?"

Mikey glanced back, a blush on his face. "... Do you think you'd be okay to tickle me?"

Donnie's mouth fell open for a moment, before being replaced with a grin. Of course; he remembered now how much Mikey liked to be tickled now. He knew something was missing in the turtle's cure for nightmares. The smart turtle and the other brothers had had a blast torturing their baby brother the night they dealt with the nightmares of the Shredder. Without giving it a second thought, Donnie gave Mikey a semi evil smile, wide enough to show the gap in his teeth.

"Oh? You mean, like this?" Donnie quickly shifted his hands from Mikey's waist to his sides, tickling at a moderate pace. Mikey squealed before dissolving into giggles. In his reaction, he pushed himself more into Donnie's chest; of course sealing his capture as Donnie wrapped his legs more tightly around him. "Is this what you're after?" Donnie teased as he tickled the sides of Mikey's ribs.

"HEHEHEHEHE Y-YEAH! HEHEHEAHAHHAHAHAHAHAHAHA!" Mikey giggled wildly, which caused Donnie to let out a small giggle of his own.

"Or," Donnie drawled out. "Maybe I should tickle you... HERE!"

Without more warning, Donnie switched to tickle Mikey's tummy, causing the little turtle to wrap his arms around himself and kick his legs a bit. He even started thrashing from side to side a bit, though the purple banded turtle knew it was just a reaction. If Mikey had really wanted him to stop, he would be pushing his hands away with more force and making it clear for him to stop. Donnie couldn't help but laugh at how cute his little brother looked, nor how much he was laughing.

"HAHAHAHAHAAH DONNIIIIIIIIIIEEEEEE!" Mikey squealed as his brother tickled lower, right around where his belly button would have been. Easily, it was one of Mikey's most ticklish spots. Donnie just laughed and grinned.

"What's the matter?" he teased. "I thought you liked it when I tickled you there."

Mikey laughed wildly, unable to reply to his brother's statement. Donnie took this as a sign to keep teasing and tickling, scribbling his fingers a little faster,until he decided to up his taunting game.

"... Tickle..."

"HAHAHA D-DONNIE!" Mikey half squealed. He knew what was coming. But Donnie ignored him and slowed his tickling to match the speed of his taunting.

"... Tickle... Tickle... Tickle..." Mikey's giggles went up a pitch or two, anticipation spread across his face. While he knew this would tickle a lot and drive him crazy, he also knew that he was having fun, and so was Donnie; the purple banded turtle couldn't wipe the smile off his face, no matter how hard he tried. "Tickle tickle tickle tickle tickle..."

And suddenly, with a burst of speed, Donnie raised the pitch of his own voice super high as he started tickling as fast as he could and teasing rapidly "TICKLETICKLETICKLETICKLETICKLETICKLE!"

Mikey lost it, a slight scream leaving his mouth before deep laughter and thrashing continued. Donnie broke into a bit of laughter himself at his little brother's reaction. It was hysterical to see him react in such a manner.

"HEHEHEHEHEHEHEHEHEHE T-THAT TICKLES! HAHAAHAHAHAHAHAHAHAHA!"

"That's the point," Donnie teased, switching spots to tickle his brother's ribs again. "Aww, is my baby brother ticklish here too?" Donnie cooed as Mikey's laughter went up an octave at the teasing. He was enjoying himself, and some how, Donnie's own giggles kept escaping his mouth as he felt his own tensions start to melt away. "Or how about here?" Donnie shifted his arms, keeping one wrapped around the laughing turtles ribs (tickling as he did so) he reached the other hand up and started spidering lightly around Mikey's neck. And that was all the orange banded turtle could handle.

Mikey thrashed again, this time with a sudden burst of strength as he managed to twist himself around so he was facing Donnie. The purple banded turtle ceased his attack in shock, before Mikey reached over and start scribbling the genius's own sides.

"H-HEY! HEHEHEHEHEHEHEHEHEHEHEHEHE!" Donnie giggled and fell back against the wall at the surprise tickle attack. In truth, Mikey hadn't even known if Donnie was still ticklish or not; he remembered they were all ticklish as kids. And Donnie thought that he had outgrown the ability to feel the ticklish sensations. Apparently, he was wrong.

"I didn't know you were still ticklish, D," Mikey giggled in delight. "I figured you would have outgrown it."

"I-I DIDN'T HAHAHAHAHA KN-KNOW EITHER!" Donnie thrashed gently under his brother's tickling fingers as more squealing giggles escaped his mouth. It was torture to Donnie, though he couldn't deny it was a little fun to be on the receiving end. But not enough to want to go down without a fight. "HEHE! BUT N-NOT AS TI-HAHAHAHA TICKLISH AS Y-YOU!"

Donnie quickly pounced on Mikey, knocking the younger turtle back onto his back. Mikey yelped in surprise, but that soon changed to giggling as Donnie tickled his sides again. Both boys wrestled on the ground a bit, taking turns tickling one another until finally both could no longer breathe from all the laughing. Donnie laid on his back, feeling even his own stressed from earlier in the night leaving his body. Glancing at the clock, he grimaced a bit when he saw that it was almost 2. Training in 6 hours.

"That was fun," Mikey giggled, rolling over to face his brother. Donnie grinned and turned to face Mikey well.

"Yes. Even though I don't think I enjoy being tickled as much as you do, it was fun to wrestle like that while simultaneously trying to best one another."

"It's called a tickle fight, Donnie," Mikey giggled and scooted closer, snuggling into Donnie's chest a bit. Donnie couldn't help the giggle that escaped his mouth when Mikey yawned deeply."I'm sleepy."

Donnie grinned. "You can camp out in my room if you want."

Mikey nodded as the two rose from their spot on the floor. Both turtles snuck out of the lab and down to Donnie's room (pausing briefly into Mikey's room to grab his pillow), where Mikey quickly curled up against the wall. Donnie chuckled, knowing that's where Mikey preferred to be in the bed, and joined his brother under the covers. The youngest quickly clung to Donnie, just thankful his brother was so cool with him liking the tickles. And, of course, not making him go back to his room alone.

"Goodnight, Mikey," Donnie smiled as he wrapped a protective arm around his younger sibling.

"Night, D," Mikey replied with a smile. "I really appreciate you listening to me... and the tickles."

Donnie smiled and nuzzled Mikey's head, causing a quiet string of giggles to erupt from the younger turtle. "Any time you need me, come get me. Okay?"

Mikey nodded as a long yawn left his mouth. Despite himself, Donnie felt himself yawn from the exhaustion. Closing his eyes, the smart turtle fell into a better sleep, knowing his little brother wasn't at war with his own mind. And he was ready to recharge to get back to his own experiments. With this new found zen he was feeling, he was beginning to understand why Mikey loved being tickled so much. Not that he wanted to be on the receiving end of tickles any time soon. But it was enough that it couldn't wipe the smile off of either of the two's face. Even in sleep.