Reasonable Doubt

Disclaimer: I do not own TMNT. I make no profit from this story.

Author's Note: This story contains no slash/incest. There will be mild to extreme cursing on rare occasions throughout different chapters. Everything takes place not long after the 4th TMNT movie, though I have adjusted April and Casey to be more in line with their personalities from the 1st film.

Thank you for taking the time to read my fic! I began writing this many years ago and have not forgotten it. I am extremely grateful to all my previous reviewers and watchers, your kind have words have really inspired me not to abandon this project, and I'm really excited to read and discuss with any new readers as well! This story has been my pet project for a number of months now as I have completed the entire first draft, and I really hope readers will find it just as thrilling as I do.

Enjoy!

-oOo-

Leonardo supposed it was his fault.

And the more he thought about it, the more he was certain of this, so he could only continue to force himself to remain patient with his younger brother.

After all, it had been his suggestion to Donatello to set up a security camera system around his most frequently visited dumpsters. He had hoped that in doing so, Don might exponentially cut back on his lone trips topside in his various attempts to find some new part or gadget he always seemed to be in need of.

Likewise, Leo was also quite aware that had the cameras not been installed in the first place, Don would have done the sensible thing and waited until after the harsh storm had passed before making his visit up top. However, after the tech-savvy turtle spied a recently dumped load from the local electronic store, it was obviously clear he was determined to make the journey topside, lest the gadgets be rendered completely useless from the recent downpour.

With what felt like the hundredth sigh uttered that evening, he reached up and wiped away the dripping water from his eyes. Though his actions were in vain as the pounding rain only poured onto his face relentlessly. The older turtle gritted his teeth as another fierce chill passed through his body. Squinting, he tilted his head back. He could only see the gray, thick clouds blanketing the sky, concealing the tops of the taller buildings of the bustling city.

As another severe shiver shot through him, Leo couldn't help but think it an interesting reaction, as he had always assumed he, as his brothers, were more cold-blooded than not. They all seemed to fare a lot worse in the winter than in summer, and he wondered why Donatello, in all his extreme curiosity of the world, had never once thought to settle this mystery once and for all.

It didn't take long for him to pull up a memory from ten years earlier to stifle that question. A time when a rather irritated Master Splinter had reprimanded a budding young "doctor" Donatello from attempting to extract blood for experimentation from a sleeping Raphael.

Raphael hadn't been overly pleased with the whole experience either.

Shaking the thoughts from his mind, Leonardo glanced down once more from where he was perched on the lip of the dumpster. His gaze fell on the crouched form of his sibling below. He frowned as he could clearly see the goose bumps raised all along Don's arms. Scooting a few inches to the left, Leo cleared his throat in hopes of catching the others' attention, already knowing it was useless.

"Come on Don, you've had enough time. Wrap it up. It's time to go."

"Yeah Leo, I just need five more minutes."

Leo had long since given up trying to tell time when it came to any of his brother's losing themselves in their own little worlds. But even he knew that Don's internal clock couldn't be that messed up.

"Don, I've given you over two hours more than what we agreed upon. That's way longer than we need to be up here. Now hurry up."

This time, the younger turtle lifted his head, a look of exasperation etched into his face.

"Leo, the whole reason it's taking this long is a direct result of you rushing me. If you had not been so impatient, I would not have dropped and lost this thing in the first place."

Shifting from where he perched, Leo tried to hold back another sigh. He nodded.

"Alright," he muttered as he hopped down, landing nimbly besides his brother. "Fine, then tell me what it is you're even looking for anyway."

"I'm not entirely sure."

An intense twitching overtook Leo's left eye and he suddenly understood Mikey's concern that it would someday pop right out of his head completely. "Come again?"

"I only saw it for a moment before I dropped it, but it looked unlike anything I'm really too familiar with. Its shape sort of resembles a soda bottle with a spoon through the opening, if that helps your search any. But it's a lot smaller than a soda bottle, obviously. It's more of a gray color than true black, and- "

Leo didn't allow the babbling turtle to finish his sentence as he reached out instead and latched onto Don's arm, yanking him to his feet. "Don, you don't even know what this thing is. So it's safe to say, no one else does either, or even that it's here. You can come and look for it tomorrow, after it's stopped raining. Now let's go."

Don had pulled away almost instantly, just as Leo had expected. The brief moment of contact had been all Leo needed to feel just how cold his younger brother's skin actually was and the frown on Leo's face deepened. He couldn't ignore the fact that of the four of them, Donatello had always had the weakest immune system. And it had only worsened within the last five years. Leo also knew that they also still had a long trek back through the damp sewers -another strike against Don's health.

"Go back if you want. Do you really not trust me to stay out for just a couple more hours on my own?"

The flatness that had crept into Don's voice forced Leo silent. He paused to stare into Don's face.

Neither of them wanted to say it.

After all, Raph went topside often, usually against Leo's wishes. Although it was an undeniable help in easing his temper at times, typically in the form of seeing a movie or "busting some skulls" down in Central Park, he had long since ceased in seeking out any type of permission for doing so. Mikey had also taken to venturing into the city almost on a daily basis, as his former job had required, upon which he had not quite fully shaken the habit.

"Don, this has nothing to do with trust."

"Yes it does. You don't believe I am capable of defending myself alone on the extremely slim off-chance I should happen upon trouble."

This time, Don's words stung. Leo forced his jaw shut and stared quietly at the other. Don's eyes narrowed sharply, but it was gone in a moment as he returned to his previous scanning of the trash below.

Leo closed his eyes as Don had looked away from him. He measured his breathing and tried to focus on loosening the muscles in the back of his neck and shoulders.

"It isn't very often that I ask you to come up here with me." Don continued, "Yet when I do, this is the reaction that I get? So, is it just because I'm an easier target to leash in than Raph, or have you just given up completely in trying to control him?"

It took almost all of Leo's willpower to keep his hands from bunching into fists as his eyes snapped back open at the sound of Don's quiet voice.

"Don," he began, forcing his tone to remain even, "you know better than anyone that I don't approve of Raphael's trips up here. Not before and not now. But you also have to understand that, well, you and he are two entirely different situations."

Don's eyes narrowed as he visibly stiffened.

"I see. So the fact that Raph is out gallivanting like some kind of vagabond at all hours of the night is perfectly acceptable. It certainly makes absolute sense that you should just ignore any rule he breaks and focus on trying to control me instead."

"It's because he does know more than you," Leo hissed tightly through clenched teeth, "At least up here anyway. He's stronger than you, and more experienced at making his way around the city. That doesn't mean that I approve of everything he does, but, while I hate to admit it, he knows his way around the city better than any of us, Don." He finished off, trying not to sound too exasperated.

Leo unintentionally flinched under the cold glare of his younger brother. He held his palms open, helplessly.

"I'm just trying to protect you, Don."

"When did I say I ever wished for your protection?"

Don had practically whispered the words, but for all Leo knew, they had been screamed inside his skull. He fell quiet as he noticed the sickening similarities the angry words and pouring rain held of a painful memory that he'd rather sooner forget than repeat.

A quiet shuffling noise caused Don's eyes to flicker over as he saw Leo bend over the garbage.

"So, you said a soda bottle with a spoon?"

-oOo-

A loud, throaty cough echoed down the long, cold sewer and Leo's footsteps slowed for the fifth time since he and Donatello had left the dumpster. It took a lot of effort to keep from frowning, and even more effort not to lecture. Instead, all he could do was wait as patiently as possible for Don to finish coughing before they could continue on.

He reached over and gently brushed off a small tick nestled on Don's arm. The dumpster had been infested with a myriad of the insects, and it hadn't taken Leo long to realize how much they agitated his already ailing brother.

The icy chillness of Donatello's skin only made Leo all the more impatient to get back to the lair and warm up. He knew Don had a cold at the very least, and he wasn't willing to wait around and let it develop into something worse. After a few more seconds, Don's painful coughs began to subside and Leo slowly resumed navigating their way down the damp passageway.

A comforting, warm blast of air greeted the two as the heavy door to the lair slid open, revealing the reassuringly familiar room within.

There were two inhabitants already seated in what made up the living room, but only one pair of tender golden brown eyes lifted up in a silent greeting as Master Splinter was able to avert his attention from the chess game he was currently engaged in with his second eldest. Raphael, who was in one of his rare, quieter moods, kept his sole focus on the game board spread before him. Slowly, he reached forward, brushed his fingers against one of the pawn pieces, and then quickly withdrew, resuming his meditative stare of intense concentration once again.

Splinter didn't speak, opting instead to watch in silence as Leo steered his younger brother to the kitchen, sitting him on one of the stools. Even from the distance, Splinter's old eyes were sharp enough to pick out the numerous small nicks that littered Donatello's arms and legs. He let out an almost inaudible sigh.

He knew that of his four sons, Leonardo and Donatello were usually the most cautious when it pertained to those types of things and it troubled him when both returned coated in water, or how Don continued to shiver. He decided to allow his eldest to finish tending to his brother in silence. He did happen to notice, however, that Don seemed to be paying exceptional care to the burlap sack he used to carry his "treasures" with, though Splinter said nothing of it as he watched the younger turtle slightly pull away from the blanket Leo now attempted to place around his shoulders.

Splinter turned back just in time to see Raphael take his turn. Reaching forward, Splinter moved his own pawn without hesitance.

"Checkmate."

Raph's eyes widened, fists clenching as a single vein of frustration popped on his forehead. His head snapped forward, and he stood up so hard his chair was almost knocked backwards.

Splinter slowly lifted himself from his seat, as Raphael gripped both ends of the table.

"Rematch."

Splinter hid a smile, as he continued to walk away.

"Not tonight, my son. It is already very late. I must turn in for the night and I advise you to do the same."

He paused for a moment, watching his second eldest slump down to his chair, eying the chess game, mumbling under his breath, no doubt replaying the game in his mind. He turned back to the two turtles in the kitchen. Making eye contact with Leonardo, they shared a mutual understanding, before Splinter turned his gaze to the other teenager seated before him.

Don, however, was so consumed with cleaning up his various cuts along his arm he didn't even notice. The rat had no reaction to this, giving only a soft, "Good night, my sons." before closing the door after him in silence.

Pushing away from the chess game with a disgusted grunt, Raph turned around in his seat and leaned up against the back of the old, worn in sofa. He looked a bit smug as he glanced to his older brother, "That was just a little bit longer than twenty minutes, don't ya think Leo?"

Intrigued by the glare that Leo threw his way, though completely unfazed by it, he instead turned his attention to their younger brother. He straightened up when he noticed just how battered up Don seemed to actually be. Shaking his head he gave a low whistle, which in turn earned him another scowl from Leo.

"Damn Donnie," Raph muttered, still ignoring the annoyed noises that continued to emerge from the oldest turtle, "What the hell happened to ya?"

"Broken bottles," Don answered before Leo could speak, "the shards of glass were everywhere."

Raph's curiosity was piqued even more now. What was so important that would have his little brother digging through glass shards? Before he could ask, Don spoke up.

"Where's Mike?"

An awkward silence clamped down on the room and for a moment all Leo and Raph did was stare, each with their own gazes of curiosity and guardedness, while Donatello continued to bandage up his arms.

Fortunately, the stillness only lasted a few seconds. Almost as if knowing his cue, the door to the lair slid open once more and the youngest bounced in, flipping his skateboard up into his left hand, the other clutching a reasonably soggy Domino's pizza box.

"Hey dudes! I'm… uh, I'm back!"

Mikey's usual jovial greeting faltered slightly at the three stares he was greeted with. He stepped forward, shooting a questioning glance over to Raph, since Don had been very quick to look away from him, and he was trying to avoid the frustrated look Leo was shooting his way.

He tried to nonchalantly step around Leonardo in order to slide the pizza box onto the table. Unfortunately, Mikey wasn't very good at reading Raph's facial cues, and he didn't manage to step away before Leonardo reached out, grasping a firm grip on the back of his shell, and gave him a sharp jerk back.

"Mikey," Leo snapped, "Where were you? You said you were going to get dinner. That was before Don and I even left!"

The smaller turtle grimaced and cast a pleading look over to Raph, who had yet to move from his position on the sofa. Raph only shrugged and looked back at Don. Mikey gave a small groan as his helpless eyes scanned the room before realizing there was no one to save him.

"I-" his voice suddenly cut off as he noticed Don's arms for the first time. "Whoa! What happened to you, bro? You look like you've been eaten alive! Nasty!"

Mikey stepped forward, effectively slipping from Leo's grasp, circling behind Don and pausing as he peered in closely, "Ew! You got bites all over your neck too! Mondo-gross out!"

"Go away, Mike." Don huffed, as he pushed his personal-space invading brother away from his neck.

"And you didn't answer me," Leo interjected. "Where were you?"

Mikey's eyes widened as he suddenly waved his arms. "Did you know they opened up a penny arcade over on 3rd street? Just a penny Leo! That's like- do you know how long I can stick around on just a dollar?"

He paused when he noticed Leo's unaltered expression, and gave a shrug, "Geez, what's the big deal? I thought we'd worked this out? I mean, Raph goes up all a time-"

"Leave me out of this."

"and it's fine! You know, it's not like I would get in any sort a trouble, I'm not that dumb. Chill out Leo."

Rolling his eyes, Mikey brushed past Leonardo as he made his way to the fridge, pulling out a soda and popping it open.

Leo said nothing, but was painfully aware of the stabbing glare sent his way from the Don, who had finished up with the last of his bandages. He purposefully tried to avoid Don's stare, keeping his attention on Mikey, though he was feeling ridiculously out of sorts as he struggled to find a proper response.

Without a word, Don abruptly pushed away from the table, the legs of his chair making a loud screech against the floor as he stood.

Mikey's eyes widened as the door to Donatello's room gave a tight click shut after him.

"Dude, what's the matter with Donnie?"