*Disclaimer: I do not own the rights to the Teenage Mutant Ninja Turtles franchise.

Author's Note: Here's chapter 1 of 'A Shell of Himself.' I hope you like it. Thank you to everyone who has taken the time to provide feedback and favorited/followed me. I really appreciate the support.

Chapter 1 – Caught Green-handed

The system tray clock on the bottom right hand corner of his computer monitor informed him that the exact time was 3:06 A.M. The font of the digital clock was almost too tiny for his tired eyes to read, but all he had to do was slant his body forward slightly and squint a few times to bring the numbers into focus. Well, focused enough so that he could decipher them.

Donatello dragged his olive-green colored hands down his face and then rested his carapace against the worn back of the task chair he was stationed at.

3:06 A.M.

That meant that he was supposed to have gone to bed four hours and four minutes ago. The reason he knew precisely how long it had been since he was supposed to have gone to bed was because it had been 11:02 P.M. on that same desktop clock when his oldest brother, Leonardo, had ever-so calmly placed his hands down on the top of Donatello's desk, leaned over him, and ordered him to turn off all of his equipment in the lab and call it a night.

Now that it was past the three o'clock hour – ante meridiem rather than post meridiem – Donnie realized that he couldn't really call it a night any more. Not if he wanted to be entirely accurate, which he did. Technically, if he went to bed now, he would be calling it a morning. Of course, Donatello had no intention of calling it a morning at this point, even though he was well aware that Leonardo would be seriously ticked off if he found out that his little brother had directly disobeyed him and forgone sleep again, just as Donnie had done the past five nights.

Sure, Donatello felt a little guilty for defying his oldest brother's very explicit commands. Okay, strike that . . . He felt a lot guilty for defying Leo's commands, but, in Donnie's defense, he had shut down most of his equipment and switched off almost all of the lights.

That had to count for something, right? Okay, maybe not . . .

Truth be told, Donnie hadn't turned off any of those things out of the goodness of his heart or even just to appease his sometimes overbearing oldest brother. No, Donnie had done those things to protect his own shell. Not for selfish reasons. Being selfish wasn't in Donatello's nature. It was well-known that the dubbed genius of the Hamato Yoshi family did not have a selfish bone in his body. All of his close-knit friends and family would personally vouch for that. Donatello always put others' needs before his own, hence the reason he was currently depriving himself of all sleep and nutrition. He was doing so out of purely unselfish reasons. He was trying to help his friends. Friends that he had recently made solemn promises to that he fully planned to keep, and, in his mind and his heart, those vows came before fulfilling any basic needs that he might have. So for the past five nights, instead of wasting time on trivial things like eating or sleeping, Donnie had locked himself away in his lab, day and night, so that he could work on the cure that he had promised to find. He had promised his friend, April O'Neil, and he had promised his friend, Timothy (aka 'The Pulverizer'). Donnie had no intention of breaking his promises.

Now, more than ever, it was imperative that Donatello develop an antidote for mutagen as soon as possible, above all else. His friends were counting on him. That was why Donatello was pushing himself so brutally hard to find a cure. He had been ever since the unfortunate incident with Timothy . . .

Six nights ago, Donatello had been forced to make a difficult choice. One that Donnie wasn't so sure he could live with himself for making, even though, deep down inside, he knew without a doubt that it was the only viable choice he had. In order to save his three brothers and the human girl he was head over shell in love with from a crazed mutagen monster, Donnie had no choice but to take that monster out. And take it out he had. To be exact, he had tricked the demented creature into ingesting an unsuccessful, highly experimental batch of retromutagen Donnie had made earlier in the day. The altered mutagen had effectively froze the creature solid inside of a glass containment unit, just as Donnie had anticipated.

The problem was, that crazed, now-frozen monster had been Donnie's friend. That mutated monster that had tried to hurt them was once a human boy. A rather inept, flabby, obtuse human boy that called himself 'The Pulverizer,' but a human boy nonetheless.

Looking back now, Donnie couldn't help but to blame himself for the human boy's most unfortunate fate.

On multiple occasions, Donnie and his brothers had saved 'The Pulverizer' (whom they later found out went by the common name of Timothy) from getting . . . well, pulverized. Timothy was a bit of a – for lack of a better word –nincompoop. The teenager wanted to be New York City's next big hero, but he lacked any kind of actual skills or abilities. Mostly, he was just a klutz. Donnie's brothers had thought of Timothy as nothing but a hopeless loser/bumbling idiot. Actually, everyone seemed to think Timothy was pretty much 'expendable.' The Kraang . . . The Foot clan . . . Heck, even Donatello's father (aka Hamato Yoshi, aka Master Splinter, aka Sensei) had referred to Timothy as a 'doofus,' and Master Splinter had always taught his sons about the values of humanity and compassion. Not once before did Donnie remember a time that their father, who just so happened to be a giant rat as well as a grand master of Ninjutsu, had called someone a hurtful name only a few seconds after meeting them. That was perhaps a true testament of just how extraordinarily incompetent Timothy was.

Still, Donnie had felt sorry for the boy. Maybe that was because Donnie felt as though he could somewhat relate to Timothy's situation. Granted, Donnie was never quite as pathetic as Timothy had been, but Donnie knew what it was like to be looked down upon. Donnie was also quite familiar with what it felt like to try your best and still not be good enough in the eyes of those you most admire. Donnie had always been the weakest fighter in a family of gifted ninjas. No amount of studying, training, or practice could ever make Donnie as good as his brothers were at martial arts. Donnie had long ago accepted the harsh reality that his three brothers were natural born ninjas and he . . . was not. He would never be as good as them. The acceptance of that reality didn't mean the truth hurt any less.

It had been Donnie's severe insecurities about himself, combined with his kind heart and gentle soul, that had ultimately caused the normally brilliant turtle to suffer a major lapse in sound judgment and decide to try to help Timothy. Donnie had even gone so far as to show Timothy some basic Ninjutsu moves so that the kid could at least have a chance at defending himself. It was a decision that Master Splinter hadn't exactly been too keen on.

Donnie could still hear his father's words replaying in the back of his head when he had told Master Splinter that he just wanted to teach Timothy some rudimentary skills.

"If you train him, you are responsible for whatever happens . . ."

Propping his elbows up on his desk, Donatello buried his face in his shaky hands. Tears started to sting his droopy eyes, but he blinked the moisture back as quickly as it had formed. He refused to allow himself to cry. This was not the time to fall apart like some useless weakling. Timothy deserved better than that . . .

Timothy . . .

". . . you are responsible . . . you are responsible . . . " The words repeated in Donnie's head like a demotivational mantra.

So much time had passed since Timothy's horrible transformation, yet Donnie could still vividly recall the events that had lead up to Timothy being mutated into a barely sentient glob of intestinal goo as if it had happened only yesterday.

"Shredder's gonna mutate just one Foot soldier first as a test. And guess what? I volunteered!"

"What?"

"I know! Isn't that cool?"

"No! Why would you think that's cool?"

"This is my chance to be like you guys. Throw some mutagen on me and boom! I'm a superhero. I'm taking Shredder down!"

"The mutagen is dangerous! You have no idea what that stuff could do to you!"

Despite Donnie's repeated warnings about how unpredictable and unstable mutagen was, Timothy's delusional fixation on becoming a hero had made it impossible to get through to him. The boy's mind was set and he completely – and foolishly – disregarded Donnie's vain attempts to stop him.

"Timothy, no! What are you doing?"

"I'm gonna be a mutant like you!"

"Um, doing the mutation thing is notoriously unpredictable . . . AND REALLY STUPID!"

In the end, all of Donatello's desperate efforts to save the human boy from himself just weren't enough. Donnie wasn't able to stop Timothy from willingly dousing himself with mutagen, nor was Donnie able to prevent Timothy from mutating into what Donnie's second oldest brother, Raphael, later referred to as a pile of guts in a jar. A crass remark, but rather apropos.

What Donnie's most uncouth brother, Raph, had meant when he had said 'jar' was the mutagen containment unit that they had stored Timothy's mutated blob-like form in while Donnie tried to synthesize a retromutagen to cure Timothy's condition. Since his mutation, Timothy had been housed in that unit in Donnie's lab up until six days ago. That was when Timothy managed to get into one of the full mutagen canisters on Donnie's desk. Consuming the mutagen caused Timothy to sprout a pair arms and legs from his containment unit, which allowed Timothy the mobility and strength needed to break out of the lab and wreak havoc on the streets of the city.

Timothy's secondary mutation had made him extremely volatile and dangerous . . . like even more so than Raph on a bad day. 'The Pulverizer' spiraled out of control and tried to destroy the turtles. Much to his dismay, Donnie had no other option than to put his friend into an indeterminate cryogenic state, essentially turning poor Timothy into a giant popsicle in order to protect his brothers from being smashed and/or melted by Timothy's acid hands. In addition to protecting his brothers, Donnie also had to protect their friend, April, who had been the one Timothy was actually going after. All because Donnie had talked about April nonstop in front of Timothy. Donnie had put her life in danger with his whining.

Ah, April . . . sweet April . . .

Yet another friend that Donnie had let down.

April hadn't talked to the turtles for weeks now. Not since her dad's mutation.

Yet another mutation that Donnie was responsible for . . .

Several weeks before, Donnie had discovered via a Kraang communication orb that the Kraang were back and were using one of their stealth ships to transport a shipment of unknown cargo. With the help of April and her father, Kirby, the turtles tracked down the stealth ship and boarded it only to discover that the Kraang were transporting mutagen canisters. Lots and lots of mutagen canisters. While the turtles were fighting the Kraang aboard the ship, several tactical errors that Donnie was not proud of were made, which resulted in dozens of mutagen canisters plummeting down upon the city, including the one that landed on April's father and turned him into a giant bat-like creature.

Donnie could still remember the horror that had befallen across April's face when his younger brother, Michelangelo, had revealed to her that they had been the ones responsible for dropping the mutagen containers on the city.

"Listen. Don't blame yourself, April. It was our fault. We spilled the mutagen. We'll fix it."

"What? Y– you guys . . . You guys spilled the mutagen?"

Upon seeing how upset April was, Donnie had tried to comfort her to no avail.

"I swear by Darwin's beard we'll cure him."

"You mutated my father!"

April had no sooner finished that sentence when her father escaped the large cage the turtles had trapped him in. Kirby bat or 'WingNut' (per Mikey) had tried to grab April, but Donnie had knocked him away with his bo-staff. Then, the bat/human mutant had flown off into the night, leaving a very angry and devastated April behind.

Again, Donnie had tried to console April, but the second time that he had reached out to her, she had jerked away as if she was repulsed by his very presence.

Then, she had spoken the words that Donnie would never forget, and though she had been speaking to all of them, she had looked at right at Donnie when she had said them.

"Don't! Don't touch me! You keep away from me! I never want to see your faces ever again!"

That was when Donatello's heart had been broken into a million infinitesimal pieces. The expression April had given him that night was nothing short of gut-wrenching. Her big, blue eyes had never looked at him that way before. It was as if she hated him.

Regrettably, April had stayed true to her word. She hadn't stopped by the Lair or even attempted to contact them since the incident. Donnie had tried several times to call the T-phone he had made for her, but she had turned it off, apparently doing everything she could to avoid them altogether. Donnie, on the other hand, could not avoid her. Not completely. Though it shamed him, he had followed her in secret multiple times to check up on her . . . just to make sure she was okay.

Okay, maybe that was a little bit creepy in a stalker sort of way, but Donnie was worried about her. She had been so upset and it was Donnie's fault. He hated himself for hurting her.

That was why it was so urgent for Donnie to find a formula that would make mutated cells turn back to normal. Maybe if he cured Mr. O'Neil, April would find it in her heart to forgive him. Then, maybe – just maybe – he and April could be friends again. Plus, if Donnie could find a way to reverse engineer mutagen into retromutagen, that might mean he could save Timothy, as well.

Of course, getting his friends back was all contingent on whether or not he could develop some sort of an antidote, and, thus far, that endeavor was not going so well.

Pulling his hands away from his face, Donnie looked to his left at his latest of many failed experiments on his desk and let out a lengthy sigh. He then looked back at the clock on his computer screen again.

3:14 A.M.

Morning practice started in a few hours. Time was ticking away and he was still no closer to a cure than the night before or the night before that . . . That meant that, most likely, tomorrow night would be another sleepless night.

Way to suck, Donnie. At least you're consistent . . .

Pressing the tips of his thick fingers firmly into his aching eye sockets, Donnie tried to massage away the sleep, the killer migraine coming on, the burning sensation, and any wetness that may have accumulated without his knowing. His body was beginning to show indisputable signs of overfatigue that would have concerned him if it had been anyone other than him exhibiting the same symptoms, but Donnie couldn't afford to worry about such things right now, nor could he allow his body to just conk out on him like it was threatening to do. He owed it to April and Timothy to keep working and he wasn't going to let something like sleep deprivation or the onset of an epic headache stop him. They deserved better than that.

They deserve better than me . . .

Drawing in a deep breath, Donatello tried to shake off his dreary thoughts. What he needed was an instant pick-me-up and he knew just the remedy. Donatello reached for his favorite coffee mug filled with an extra strong serving of now room temperature liquid caffeine and guzzled the remaining contents of the cup down, savoring the all-too-fleeting bitter taste that rolled down the back of his dry, scratchy throat.

That ought to do the trick. Just need to get the brain stimulated again is all . . .

As he waited for the caffeine high to kick in and hopefully give him his fifteenth or sixteenth wind (he had lost count of which wind he was on hours ago), Donnie used the heel of his foot to turn his blue office chair about ninety degrees so that he could lay eyes on Timothy's containment unit, thinking maybe it would summon some much-needed inspiration. He immediately regretted doing so. Not just because of the guilt that devoured away at him when he stared at Timothy's frozen form, but also because he was so dizzy, he just about fell out of his chair.

Turning back towards his desk so he could use it for support, Donnie pushed his empty ceramic mug aside to make room for the scientific equipment necessary to conduct his next experiment.

The morning was still young and there was much work to be done.

The clock beside him read 4:15 A.M.

If he fell back to sleep now, he'd still get a few more hours of rest in before morning practice. However, that task was not as easy as it had sounded in his head. Especially not when one felt as though they were now wide awake.

Leonardo rolled onto his right side for about the fifth time in the last half hour, trying to find a more comfortable position, but that was no simple feat when you had a bulky shell on your back. Leo had been tossing and turning for the better part of an hour now, but he just couldn't achieve a tranquil enough state for sleep.

At this point, Leo had already kicked most of his covers off, thinking that perhaps the room's temperature may have been contributing to his current case of insomnia, but then, he remembered that he was cold-blooded. Warmth didn't keep him awake. It helped him to sleep.

Rolling onto his carapace and draping one leg over the side of his bed so that his foot just grazed the floor, Leo tucked an arm behind his head and stared at the ceiling. He let out a long sigh, like he was deflating all of the air out of his lungs.

His mind kept telling him that he needed more sleep, but his gut was telling him that something was off.

As much as Leo wanted to stay in bed, he couldn't just ignore his gut. After all, his gut instincts had always been uncannily accurate. Oftentimes, Leo's youngest brother, Michelangelo, had claimed that Leo's stomach was to hunches as Donnie's brain was to big words and Raph's fists were to punching things. That was why whenever Leo said that he didn't have a good feeling about something, Mikey would start wigging out.

Leo pushed himself up so that he was seated on the edge of his bed. He rolled his shoulders and shifted so that his joints popped back into proper alignment before getting to his feet. He then padded to his door and silently slipped out into the hall of the dormitory area.

The first room Leo approached was his immediate younger brother's, Raphael. Leo figured that Raph was the most likely to get himself into trouble, so it seemed only logical to check up on him first. As quietly as possible, Leo pushed the door to Raph's room open just wide enough to poke his head inside and verify that Raph was in his bed. Once he saw that Raph was sleeping soundly, Leo made a swift exit, not wanting to chance having Raph wake up and see him standing there watching him sleep. That would have been extremely awkward and there's no way Raph would react favorably.

The next room Leonardo headed towards was his youngest brother, Michelangelo's bedroom, but Leo didn't need to bother going into the room to see if Mikey was inside. From outside of the door, Leo could hear his baby brother mumbling and chattering merrily in his sleep. Even while slumbering, Mikey couldn't keep quiet or still for more than a few seconds at a time. A small smile passed Leo's lips as he thought about his happy-go-lucky brother's zany antics. No one could ever accuse Mikey of being boring, that much was for sure.

Walking away from Mikey's doorway, Leo tiptoed towards his second youngest brother's room as quietly as he could, knowing that Donatello was the lightest sleeper of his siblings. The last time Leo had seen Donnie, the genius was shutting down all of the equipment in his lab per Leo's orders. Leo had noticed how worn out his younger brother looked and the oldest turtle had decided to mandate an earlier bedtime for the brainy turtle.

It had been a rough evening on all of them. Leo's wicked sore muscles were proof of that.

Due to a most unpleasant run-in with a dozen-plus Footbots while searching for mutagen canisters, the four brothers had opted to shorten their nightly patrol. Luck had not been on their side that night. The band of brothers hadn't located a single container of mutagen and Mikey had hurt his wrist during the fight. Leo, the dutiful leader of the team, had called for a tactical retreat, and, after some initial grumbling from Raph, the four brothers had used a smoke bomb to slip into the sewers and escape the robotic ninjas that had been effectively waxing their shells. Once down in the depths of the sewers, no one – not even belligerent Raphael – had objected to cutting their losses and heading back to the Lair for the night.

Upon their return home, Donnie, not surprisingly, had gone straight to his lab rather than taking the opportunity to go to bed at a decent hour for once. That was when Leo had decided that an intervention of sorts had become necessary and that he had to put his foot down.

Leo knew that Donatello had been burning the candle at both ends as of late, putting in late-night shifts in his lab . . . possibly all-nighters. That was why Donnie had looked so exhausted all day long, and, it was most likely the reason that Donnie's moves had been less-than-stellar during their skirmish with the Footbots. Leo had had to block a blow meant for Donnie at least twice during the battle and Raph had thankfully grabbed Donnie just before the genius was about to accidentally take a swan dive off of a rooftop.

Donnie had definitely been sloppy and distracted during the fight, which could have been disastrous.

Well, more disastrous than it already was, Leo groaned in his head.

Leonardo had already made a mental note to confront his little brother about his performance after morning practice. Leo would have lectured Donnie about it before going to bed, but Donnie had looked so dead-tired, Leo didn't think he'd be able to stay awake long enough to hear him chew him out.

Slowly pulling down on the handle of Donatello's door and pushing it open with the slightest of movement so as not to be detected, Leo crept inside of Donnie's room to check on his younger brother only to discover that there was no brother to check on. Donnie's bed was unoccupied and showed no visible signs of having been slept in any time recently. The bedding and pillow appeared to be untouched and arranged eerily similar to the last time Leo had been in Donnie's room, which was four or five days ago.

Initially, a flood of panic washed over Leo when he thought back to the bad omen kind of feeling he had gotten in his gut earlier. The feeling that had told him something was wrong. The sudden realization that his second youngest brother was missing sent Leonardo into a momentary tizzy as his sometimes overactive imagination began to sift through the scores of worst case scenarios that popped into his head. Each one was more gruesome than the next. Then, Leo's sensible side took the helm once again and panic was quickly replaced by irritation.

Staring down at Donnie's vacant bed, Leo clenched his fists at his sides and pressed his lips into a thin, grim line. He knew exactly where Donatello was. The very same place Leo had left him in when he had mistakenly assumed that his little brother had listened to him.

Something along the lines of a growl rumbled in the recesses of Leo's throat.

Exiting Donnie's room in far less stealthy fashion than he had entered, Leo marched through the arched stone aperture that lead to the main living space of the Lair and headed straight for Donatello's lab.

Normally, Leonardo would have knocked on the laboratory door, or, at the very least, announced his presence before entering his genius brother's domain, but, in this case, Leo wasn't feeling all that courteous and he skipped such respectful formalities. It was a breach of manners, Leo knew, but he wasn't really concerning himself with such things at the moment.

When Leo stepped foot inside of the lab, it took less than a split-second to spot his younger brother, who was hunched over his desk, pouring something into a beaker. As soon as Leo made his way past the threshold of the lab entrance, Donnie let out a sharp gasp and one of his hands instinctively flew to his chest to make sure his heart was still where it should be. The other hand nearly dropped the test tube he was holding.

Needless to say, Leo had startled Donnie.

"L – Leo! What – what are y – you doing up?" Donnie stammered out in a whiny tone that came out about a half-octave higher than Donnie had wanted. The genius turtle was also vaguely aware of the undesirable tremor that rocked his voice. It was certainly not a confident way to start off what was sure to be an uncomfortable conversation.

"Funny . . . I was about to ask you the same thing," Leo said in a much colder manner than Donnie had expected, which was undoubtedly a bad sign of things to come. Donnie also noticed that Leo approached his desk using far shorter, ungainly strides than was typical of his graceful big brother. He was almost . . . stomping. Kind of like Raph would.

This is so not going to bode well, Donnie thought to himself.

Placing the test tube he had been holding when Leo had barged into the lab into a test tube rack, Donnie then quickly put his hands under his desk to hide the fact that they were trembling. Once his hands were concealed from Leo's line of sight, Donnie sat in premeditated silence, opting not to respond to Leo's comment so that he could buy himself some time to think. Well, that and every response that popped into Donnie's head was sarcastic in nature and he was fairly certain that Leo was not in the mood for his wit right about now.

Donnie was right. Leo was so not in the mood.

A scowl creased Leonardo's features as he stared at his younger brother, who was intently staring down at the surface of his desk.

It didn't take a scientific genius like Donatello to see that said turtle was doing his best to avoid eye contact with his oldest brother, which only irritated Leo all the more. The least Donnie could do was have the decency to look him in the eye after what he had done.

"Donnie! Do you have any idea what time it is?" Leo asked, folding his arms across his plastron and tapping his foot on the floor impatiently. Again, Leo's behavior was more befitting of Raphael.

Apparently, Leo got up on the wrong side of the bed this morning . . . Donnie thought to himself, somewhat amused.

Of course, the irony of that thought was not lost on Donatello. The moment Leo had come in, showing clear signs of anger, it had occurred to Donnie that Leo was crabby because he hadn't gone to bed. The paradox would have been hysterical if Leo wasn't so darn grumpy.

The scowl lines on Leo's face deepened as he waited for Donnie to reply to his question. Leo could have sworn he saw the ghost of a smile pass Donnie's lips, but he gave his little brother the benefit of the doubt, thinking there was no way Donnie could have possibly found the situation the least bit humorous.

Then, as if to prove Leo wrong, out came a taste of Donnie's infamous sarcasm.

"Is that question supposed to be rhetorical or do you actually want me to tell you what time it is?" Donnie had not meant for his answer to sound quite so abrasive, but once it left his mouth, it was obviously too late to take it back. Unfortunately, life didn't have an undo button like computers did. Donnie oftentimes found himself wishing that it did. It would have made things so much easier if he could just click a button and wipe out all of the stupid things that he had done in his life.

Timothy would still be human . . .

April would still be my friend . . .

My brothers wouldn't think I'm useless . . .

"It's four o'clock in the morning, Donnie!" Leo howled in the shrill, snarky voice he reserved for when he got really worked up about something. Leo liked to think that he had honed his vocal intonations enough that he could imply 'have you lost your mind?' or 'what were you thinking?' without actually having to say the words.

Dropping his arms to his sides, Leo balled his hands into tight fists as he stooped over Donnie, who was still sitting in his chair, looking down at his desk. Obviously, talking to the top of Donnie's head was not ideal. Leo really wished Donnie would just look at him so he could better gauge what Donnie was feeling right now. Sometimes, Donnie could be difficult to read. Whereas Leo's other two brothers didn't try to hide their emotions – even if Raph's emotions pretty much consisted of anger and more anger – Donnie had a tendency to keep his emotional cards close so no one could see them. Sure, they could visibly see if Donnie was upset about something, but a lot of times, that visual confirmation was all of the details they got out of their introverted brother. Donnie had a bad habit of bottling things up inside. Instead of talking to his family or friends, his solution was to hide away from them in his lab so he could try to work through things on his own.

Hence the reason Donnie was in his lab at this very moment.

Leo was just starting to feel sorry for his little brother when Donnie spoke again.

"Technically, it's closer to four – thirty," Donnie corrected Leo, lifting his head up slightly and pointing at the computer monitor to substantiate the accuracy of his statement. In all actuality, Donnie was only trying to be helpful when he had corrected his brother, but Leo hadn't seen it that way. It was yet another time that Donnie's mild case of OCD had gotten him into trouble.

Me and my big mouth . . .

"Don't get smart with me, Donatello!" Leonardo scolded, planting his hands on his hips to strike one of his classic 'I'm the leader and you're not' poses that had clearly come straight from the playbook of Leo's all-time favorite television character, Captain Ryan, from that extra cheesy Space Heroes cartoon Leo was so infatuated with.

Did he seriously just tell me not to get smart with him? Seriously? That's like bringing Mikey to a pizza parlor and asking him not to eat anything.

A hundred and one snide comebacks raced through Donnie's brain at all once, but he had to bite his tongue, hard, in order to keep himself from capitalizing on such an easy opportunity to let his sarcasm run rampant at his oldest brother's expense. Besides, Leo had just employed his full name, which warned Donnie that his older brother was not to be trifled with right now. Leo didn't use their first names unless he really meant business.

Now gnawing on the inside his bottom lip rather than his tongue, Donnie wrapped the hand that he had used to point at his computer just a few seconds ago around his forearm and rubbed his palm up and down his arm nervously. Still purposely attempting to avoid the disapproving stare that Donnie presumed Leo was giving him, Donnie's eyes wandered back down to his desk. That was when his gaze locked onto the beaker three-quarters full of mutagen. That was when his eyes started to gather moisture once again.

He could still hear himself making that oath to Timothy.

"I promise, Timothy. One day, I'll turn you back."

He couldn't stop thinking about the vow he made to April.

"I swear by Darwin's beard we'll cure him."

He had promised them something that he wasn't even sure he was capable of.

Smart one, my shell . . . I'm about as useful as a glass hammer.

Donnie was half-tempted to throw that beaker of mutagen across the room, but he didn't want his brother to bear witness to him lose his temper. Leo was already disappointed enough in him as it was, just like everyone else who had the displeasure of knowing him . . .

He had let Timothy down.

He had let April down.

Now, he had let Leo down.

Was there no end to his incompetence?

Donnie was so caught up in his own misery that he didn't even notice Leo bend down right beside him. At least, not until he felt Leo's hand cup firmly underneath his chin and pull his face up towards him, forcing Donnie to look at him against his will. Donnie immediately tried to break free of Leo's grasp, but then Leo curled his other hand around the back of Donnie's neck to hold his brother in place.

It was at this point that Leo realized what poor health Donnie was truly in and he kicked himself for not noticing it sooner. Donnie's normally bright, beaming ruddy-brown eyes were red-rimmed and duller than Leo ever remembered seeing them. Even with the scant lighting in the lab, Leo could still see the dark circles and bags under Donnie's cloudy eyes. His brother's purple mask could not hide how terrible Donnie looked.

Leo wondered how the heck he could not have seen this before. Yes, Leo had observed that his second youngest brother had looked more tired than usual, but this . . . This was beyond tired. Donnie looked like a shell of his normal self.

Surely, Donnie couldn't have looked this bad last night . . . I would have noticed . . .

Examining Donnie's wilted figure before him, Leo shuddered at the sight of his brother. The skin on Donnie's face was hollowed, sunken, and pale and it felt much warmer than it should. Not only that, but Leo could feel his brother shivering in his grip.

"Donnie . . . when was the last time you got some sleep?" Leo asked with a mixture of concern and frustration as he pulled his brother closer.

Donnie's ashen cheeks flushed with a slight tint of scarlet as he once again tried to pull away from his brother's hold, but Leo did not let up. If anything, he just clutched Donnie tighter, to the point that Donnie was pretty sure it was going to leave marks behind.

"Leo, you're hurting me," Donnie practically whimpered, still futilely attempting to wriggle himself loose.

Leo noticed that Donnie's efforts to get away were feeble at best and he was getting more and more flaccid by the second. Leo had felt more resistance from a blanket.

"Answer the question, Donatello!" Leo barked, not slackening his grip even the slightest bit. Leo hated to be so harsh when his brother was clearly not well, but he had to know the answer.

Donatello's eyes widened to twice the size that they had been moments before and he peered up at Leonardo, nonverbally pleading with his big brother to release him, but Leo didn't budge.

The anger burning inside of Leo was making it difficult for Leo to think straight. At this point, he wasn't even sure who or what he was truly mad at.

"How long, Donnie?" Leo hissed, giving Donnie a vigorous shake.

"I . . . I'm not sure. N – not s – since the night I – I froze Timothy . . . I – I think," Donnie stuttered and he closed his eyes so that he did not have to see Leo's reaction.

"What? That was like five or six nights ago! You haven't slept for almost a week? Why would you do that?" Leo asked and his voice was growing more and more agitated as his stress level rose. He couldn't believe that Donnie would neglect his own personal safety like this. Even worse, Leo couldn't believe that he had neglected Donnie's safety like this. As Donnie's big brother and his leader, it was Leo's responsibility to protect and watch over Donnie. How could he not have seen that Donnie had been abusing himself so badly? How could he have let it go on for so long?

"Leo," Donnie breathed out his brother's name, and then, his voice all but abandoned him before he could go any further with what he had been trying to say. He cursed himself for being so weak.

"And when was the last time you ate something, Donnie? And I mean solid food! Coffee doesn't count!" Leo snarled, not even realizing that he was still shaking his little brother with each syllable that he spoke.

"I . . . I don't know. Maybe . . . a few days? I . . . I was – " Donnie tried to explain, but Leo didn't allow him finish.

"You were what, Donnie? Trying to make yourself sick? By starving yourself? By not getting any sleep?" Leo seethed and his blue eyes narrowed into nothing more than angry slits zeroed in on Donnie.

Donnie cowered away as much as he could, which wasn't much at all. Leo's grip was unfaltering.

"No . . . I . . . I was . . . I had to –" Once again, Leo cut Donnie off before he could complete his sentence. It was a getting to be a rather annoying trend and Donnie could feel his fear edifying into something more aggressive than what he was used to feeling.

"You didn't have to do anything other than go to bed, which I told you to do hours ago, but you chose to disobey me!" Leo snorted, putting heavy emphasis on the words 'have' and 'chose.' Donnie could see and hear that Leo was clearly upset, but, then again, so was he.

"I couldn't just drop what I was doing, Leo! I had work to finish!" Donnie snorted back, taking Leo somewhat by surprise.

"Work that could have waited until morning! You completely disregarded my orders, Donatello! I thought I could trust you, but apparently not," Leo uttered, fully intending for the words to cause offense. With that said, he finally released his hold on Donnie's chin, but only so that he could pull his T-phone out of his belt. As Leo started to push buttons on his phone, his other hand remained tightly clamped around Donnie's neck, effectively keeping him pinned down in his chair.

"Wait! Wh – what are you doing?" Donnie asked with anxiety filling his voice. His moment of anger had subsided and he was now trying frantically to free his neck from Leo's iron grasp to see the screen image on his oldest brother's T-phone, but Leo used his better leverage point to keep Donnie trapped in his chair while he sent off a quick text message.

"Sorry, Donnie, but you left me no other choice. Raph will be here soon," Leo said, tucking his T-phone back into his belt.

"What? You texted Raph? At four o'clock in the morning? Are you insane?" Donnie shrieked, his voice nearing soprano range. If circumstances were a little different, Leo might have laughed at Donnie's high-pitched voice.

"Well . . . technically, it's closer to four – thirty, remember?" Leo said with a bitter smirk, throwing Donnie's prior smart-aleck response back in the genius's face without an ounce of sympathy.

"You're out of your shell! Do you even realize what you've done? Raph is gonna de-shell us both for waking him up!" Donnie snapped, struggling to keep his volume down to a 'non-wake up the entire Lair' level.

Knowing exactly what he had done, Leo continued to hold a now very-panicked Donnie against his will until a very-irate Raphael came trudging into the lab, much like a raging bull entering a fighting ring. It was painfully obvious that Raph had just woken up and it was even more painfully obvious that Raph was not a happy turtle. Not at all . . .

Donnie gulped down the lump stuck in his throat, loudly. Leo gulped as well, only he was a little more subtle about it.

"I got your text, Leo. Someone better have a darn good reason for waking me up," Raph growled in a gruff voice as he tilted and turned his head from side to side to audibly crack his neck. Raph liked to use neck cracking as an intimidation tactic of sorts. He wanted to be sure that his brothers understood that they had seriously teed him off when they had decided to interrupt him from what had been a really pleasant dream.

"Oh, it's good, all right. I just found out that Donnie hasn't slept for five or six days, Raph. Not since the Timothy incident," Leo announced, fully aware that he had just tattled on his second youngest brother like they were little kids again. Leo wasn't exactly proud of that fact, but Donnie's health came before his pride. Leo knew that Raph would have an easier time getting Donnie to go straight to bed than he would. Sure, that's because Raph would throw Donnie over his shoulder or drag him kicking and screaming, but at least Donnie would get some sleep. Well, after he calmed down.

"You what?" Raph grunted, fixing a livid glare at Donnie, who was now visibly shaking all over. Leo wasn't sure if that was because Donnie was sick or because he was frightened of Raph. "When I said you looked tired and asked if you were okay yesterday, you said you were fine! You lied to me!" Raph thundered, pointing a foreboding finger at Donnie.

"I – I wasn't lying! I was fine! I am fine! You two are totally overreacting. Now, will you please just leave me alone so I can finish up my work before practice?" Donnie asked almost mockingly and he had observed that as he was making his request for his older siblings to leave, Leo had backed away to give Raph full access to him. Donnie looked up at Leo as though he was a traitor for doing so. In a way, Leo was. It was kind of like he was handing Donnie over to the enemy.

"Oh, don't think you're getting off that easy, Brainiac! You brought this on yourself!" Raph roared menacingly, cracking his knuckles. "You're going to bed, now! You know the routine. And I suggest you cooperate and keep quiet this time. You don't want to go waking up Master Splinter again, do you?" Raph asked snidely, following with a crooked sneer.

"No! Don't touch me!" Donnie shouted, pushing himself up out of his chair and holding his hands out to defend himself from Raph's advances.

Unbeknownst to everyone in the lab at the time, Donnie getting up so fast was a mistake. A really, really big mistake.

"Donnie . . . "

As soon as Donnie stood up, the edges of his vision started to soften and everything around him started to get all white and fuzzy, like his brain was using a blurring effect from some kind of photo editing software. Then, all of the sudden, Donnie's head felt as though it was a balloon floating high above him and his skin started to tingle and go numb.

"Donnie? Donnie!"

Confused by what was happening to him, Donnie looked to his brothers for answers, but he could barely see them through his now spotted and distorted eyesight. It was at that point that he realized his hearing was no longer working the way it should be, either. He could hear that his brothers were speaking in what sounded like panicked tones, but everything they were saying was a jumbled up mess, completely incomprehensible, as if they had switched languages when he knew they hadn't. Raph didn't even know a second language. Not unless cussing was considered a language.

"Donatello!"

As his brothers' voices began to fade into nonexistence, what Donnie could still see through his hazy eyes started to spin relentlessly and Donnie could feel his breathing start to catch in his chest, as if his lungs were shutting down on him. Scared out of his shell, Donnie was about to call out for help when his world rapidly went black and he felt his legs give out underneath him. And then . . . there was nothing.

To be continued . . .