They walked in silence for a while, something that wasn't necessarily a strain for them. Unlike either of Leo's other brothers, Donnie was easy to be quiet with, which made moments like these comfortable.

They listened to the mundane hum of the sewers, the trickling of water through pipes and down the brick walls of the tunnels, the squeak and patter of rats moving through the shadows, the rumbling of subway cars in the distance. As Donnie followed the cables along the wall with his flashlight, looking for the glitch, Leo strolled next to him, occasionally glancing toward the beam of light moving along the wall, but mostly watching the shadows for movement outside of their own.

He kept to his own thoughts, vaguely wondering what tone the atmosphere might've obtained if Raph had joined them on this little stroll. He rubbed the back of his hand across his cheek, forgetting until then the scars blemishing his face. He sighed to himself, suddenly deciding thinking probably wasn't the best.

"So …" Donnie said.

Leo's muscles tightened, already aware what his brother was going to ask.

"Have you given it anymore thought?"

The turtle in blue pursed his lips, keeping his eyes on the trail in front of them. "I don't exactly have your thought process, Don. I'm going to need more time than that."

Donnie exhaled a chuckle. "I know. I was just checking your progress."

Leo bit the inside of his lip, quiet for a minute as a slow heat blossomed on his cheeks. He rubbed the back of his neck, and when he spoke next, his voice was just barely audible.

"Since we're on the subject, can I ask you something?"

Donnie shrugged. "That's what I'm here for, right?"

Leo allowed himself a smile. This was what he liked about Donnie, the only one of his brothers that cared more about listening than imposing his own arguments. Sure when he got into talking he tended to ramble and his vernacular liked to roam into realms of factual intelligence that was hard to follow, but when he wasn't being asked a specific question, Donnie had a particular talent for paying attention. And this was Donatello—Mr. Extra-Sometimes-Unnecessarily-Thorough. He didn't just listen, he made it his duty to try and understand, which only made asking him questions that much easier.

Leo pulled in a breath. "Do you … Do you think it's weird?"

It was only now that he turned his eyes toward his younger brother. Rather than watching the wall, Donatello was now gazing at Leo with soft brown eyes. He didn't smile or frown but pressed his lips in a thoughtful kind of way, turning his eyes around the tunnel as he contemplated an answer. He sucked in a breath and then exhaled confidently.

"No," he said finally.

This did more to intensify the heat in Leo's cheeks than to cool it. He wasn't sure what response he'd expected, but it wasn't that. "No?" he said.

Donnie nodded. "Do you think it's weird?"

Leo faltered, eyes shifting again. "Well I … I mean—Raph's my brother."

"He is … Do you want to hear my thoughts?"

Leo nodded. He didn't tell his younger brother that his thoughts were exactly the thing he was desperate for.

"Well ... We are our own species of sentient beings. We never have and never really will fit into human society. So we've always lived by our own rules, our own sense of culture. I wouldn't say that human ideals necessarily apply to us. What's weird to you is an idea that the humans say is unacceptable according to their principle beliefs. Love, both between same sex and siblings is neither encouraged nor really accepted, but the last time I checked, neither was the existence of mutants living in the sewers and lurking around the city at night."

He smiled and Leo's shoulders leveled.

"You realize we got lucky," Donnie went on, "with Casey and April? And how many more enemies do we have than friends? We're all we really have, Leo. And for fifteen years, we were all the company we ever grew up knowing. In a situation like ours, there was already a solid eighty-six point seven percent chance that something was going to blossom between at least two of us. Even without that, we love each other anyway, and there's nothing wrong with that."

Leo pursed his lips to the side. "What about Master Splinter?"

"What about him?"

"He was human once. All of those rules applied to him at some point. Wouldn't they get passed to us?"

Donnie glanced away again as he considered this, but the resolution in his gaze never waned. "Well, if you're worried about Sensei's approval, that's something you have to take up with him," he said with a slow shrug. "But even Master Splinter said that the human world isn't something he's a part of anymore, and I've got the distinct feeling that he'd understand, Leo. Heck, he might even know already. It is Splinter."

Leo's stomach squirmed. He didn't want to think about that.

"You know," Donnie continued, his voice lowered, "April and I wouldn't necessarily be socially acceptable either—if we were ever anything more than just friends. Same thing with you and Karai."

Leonardo looked toward his younger brother who now had eyes on the mucky sewer floor. There was a distant hopelessness to his gaze that made Leo's chest tighten.

"But … would you let that stop you?" Donnie asked, turning his eyes back on his older brother.

Leo shook his head in silence.

"Neither would I."

They shared an understanding smile and from there continued to walk on in a space of comfort.

"How is that going by the way?" Leo asked.

Donnie rolled his eyes. "It would be going great if Casey had never entered the picture," he said bitterly.

Leo tried not to let his grin get out of hand. He was supposed to be sympathetic. But the strength that Donatello carried in the way he felt for April was undeniably adorable. "I thought you just said we were lucky to have met him?"

Donnie scoffed. "Yes, we, as a unit, are lucky. I never said that meant I actually like having him around."

Leo shook his head to himself, still smiling. "You know, Donnie, you should try letting April like you sometime."

Donnie paused, completely stopping in the middle of the tunnel as though he'd hit a barrier. He raised a brow at his older brother. "What?"

Leo shrugged and continued to walk on. "You always try so hard to get her to like you, to look cool in front of her, and make her see why you think you're worthy, but the truth is, I don't think you really need to do that." He glanced over his shoulder. "I'm pretty sure if you'd just relax and allow her to see you for who you really are, you'd have a better shot with her. Because … Well, to be honest, Don, you're a pretty extraordinary guy."

Donatello blinked, and even through the shadows Leo could make out a blush under the green tint of his skin. "Y- … Yeah?"

Leo nodded.

Donnie smiled to himself and shined his flashlight back on the cables, beginning to walk again. "You know, since you told me about Raph confessing his feelings for you. I've been wondering ... Maybe I should tell April?"

Leo shrugged and faced forward again, strolling ahead. His initial response was to note that he was one-hundred percent sure April was already well aware, but he wasn't sure how this would affect his younger brother's confidence. So he gave a general, "It couldn't hurt."

"But that's just it. It could. There are all kinds of variables to consider, not to mention there's about twenty-three ways she could respond. And on top of that, a countless number of ways I could say it, but what if she—"

"Shh." Leo stopped and threw a hand out behind him.

"What?"

"Did you hear that?" Leo said, tilting his head right and straining his ears.

He wasn't sure what he was listening for. He wasn't even sure what he'd heard the first time.

After a moment of silence, Donnie decided to wave his light toward the cables again. Leo saw him moving closer to the wall out of the corner of his eye, as though he'd spotted something, but the leader did not move. His blue eyes stared down the darkness of the tunnel at the point where his beam of light vanished into a wall of shadows. An icy foreboding started to creep up his spine and made goose bumps rise on his arms.

The atmosphere had shifted a moment ago. He hadn't noticed until he'd stopped walking. But it was definitely different, heavy, more crowded. Something was lurking in the shadows somewhere—close.

He slowly closed a hand around the hilt of one of his katana, but did not withdraw it yet.

"Leo."

Leonardo's eyes shifted cautiously away from the darkness and toward his brother who was gesturing toward the fat cords hooked to the sewer wall. Leo drew closer and peered down at one of the cables where two holes had punctured the rubber jacket and frayed the wires.

He furrowed his brow. "They're—"

"Bite marks," Donnie said with a nod.

Something shifted in the shadows behind them and Leo whirled around, whipping his flashlight out as though it was one of his swords.

"But they've got to be about two point three, two point four centimeters in diameter …"

Leo, pulse stuttering in his chest, slowly began arching the beam of his flashlight up the wall, waiting for the moment that it'd land on the thing that was hiding.

"… Maybe five and a half centimeters long—and the circular contour—they've got to be fangs. It's reptilian …"

Leo could feel his eyes growing as his chest tightened, like the oxygen was getting squeezed out of his lungs and stuffed into his head.

The light had found it—on the ceiling, reflecting the beams back at him from white, silvery-purple scales.

He backed slowly toward the wall until his shell hit his brother's and he could go no further. "Donnie."

"What?"

Donatello turned and his inhale echoed throughout the tunnel as he caught sight of it too. The beam of his flashlight joined Leo's on the pipes above and illuminated the mutant's entire figure, thick coils wrapped tightly around the pipes, bigger and longer than he remembered. Then again, he'd never been this close to her, at least not while she was so still.

His eyes followed her form from her tail all the way over to her head, which was rising now, bright green eyes glaring at them fluorescently.

A low, threatening hiss reverberated off the walls of the tunnel and her whole body began to move, slowly uncoiling, loosening its vise around the pipe as she lowered herself to the floor, torso first. Her tail followed, thumping the cement with a heavy splash. She raised herself up, and both boys backed away until their carapaces met the wall.

Donnie's beam of light began to quiver. Leo stretched an arm out across his brother's plastron as Karai slithered closer, leaning forward so that her face was level with theirs and Leo could see each individual scale rippling with iridescence across her snout.

She opened her mouth, revealing those long, pointed fangs and strings of glittering saliva. She hissed, sharp and loud, and Donnie's flashlight hit the ground, flickered out and rolled into the sewage. Leo felt Donnie's hands close around his forearm.

"Leo," he squeaked.

"Don't move," the leader whispered, his voice calm and level. He kept his countenance flat and undisturbed, but truthfully it was frightening staring down a ten to fifteen foot snake whose fangs were mere inches from his face—no matter if it was Karai or not.

She hissed again and then closed her mouth and leaned closer. Donnie's grip tightened, but Leo remained still. He closed his eyes and held his breath as her snout grazed against his skin, moving from his face to his neck and then his shoulder, as though she was searching for something.

He only let out his breath and opened his eyes when she followed his arm with her nose and began to sniff Donnie who trembled and whimpered, craning his face away from her with his eyes squeezed shut too.

Leo watched and felt his chest rising and falling quickly, though he kept his breathlessness silent. He forced himself to keep calm even when she flashed her fangs again centimeters from Donnie's neck as she hissed angrily.

"Karai," he called, as solidly as he could.

She did not acknowledge his voice. There was a flash of white and a splash of unsettled sewage as her tail whipped around and began winding around Donnie's legs.

Donatello's panic was not so contained now. "Leo," he said, squeezing his arm so hard that Leo's fingers started turning cold with the lack of blood flow.

"Don't move," he repeated, to which Donnie moaned. Karai's tail was already up to his waist.

"Karai," Leo called again, this time allowing the desperation to filter through his voice.

Her scales brushed by his arm, smooth with sharp ridges, blanketing pure muscle that snatched a strangled gasp from Donatello as she squeezed his torso.

Leo gritted his teeth and reached for the hilt of his katana again, shifting into a ready stance, his right arm now trapped both in Donnie's clutches and Karai's coils. "Karai, don't."

"Leo," Donnie rasped, the very end of her tail now curling around his throat. "She doesn't know who she is. You have to—"

His voice was cut off by a choke and Leo yanked out his sword, positioning the tip of the blade threateningly toward her tail.

"Karai!" he shouted, his grip tight and trembling. "Let him go … Miwa!"

She jerked, as though someone had thrown something at her. Her hissing quieted and she snapped her gaze to Leo, luminous green eyes softening as though with surprise. His heart stuttered, and he drew back a little with his katana.

"Miwa," he repeated.

She gave one curt hiss and then immediately began to uncoil. Donnie gasped.

"You remember," Leo said, slowly returning his sword to its sheath without looking away from her. "That's your real name. That's the name your father gave you—Splinter … Hamato Yoshi."

A high-pitched screech speared his ears and she lunged for him faster than he could grab for his sword again.

"Leo!" Donnie cried as the blue-banded leader was pinned to the wall and Karai's snake-head hands wrapped around his neck.

He gasped and panted, failing now in containing his panic. "Karai," he choked, abandoning his weapons and tugging at her arms. "It's—me. It's Leo!"

He glanced around her and saw Donnie rushing up with his bō staff drawn.

"No! No—Donnie, don't."

Donatello froze, arms raised over his head, ready to strike, eyes wide with a halting fear.

"I can …" Leo's muscles tensed as Karai's coils tightened. "Miwa," he said, looking back into Karai's glowering green eyes. "We can—take you to him, to Splinter …"

Her mouth opened until it was wide enough to fit his head inside. He turned away as she shrieked again, serpent slaver spraying his face.

He opened his mouth to speak, but his voice was completely severed by her grip and became nothing more than a choke. Black rings started to form in his vision and he could feel his pulse in his brain.

Her teeth dove for his face, mouth agape, and he squeezed his eyes shut.

There was a cry and a heavy thunk, and immediately Leo could breathe again, the cool sewer air rushing down his throat and into his lungs. He opened his eyes and watched Karai's coils lose their vigor and her eyes roll back into her head. Her snake-head hands slid away from him and she fell to the floor like a tree toppling stiffly to the ground, quivering the floor under her weight.

Leo's knees shook and he sank against the wall, staring down at her until he looked over at his brother who was watching him with wide eyes, clutching his staff close to his plastron.

"I'm sorry," he said breathlessly. "I didn't want to watch her eat you."

Leo nodded and reached out a hand. Donnie took it and pulled him upright, steadying him on his feet.

The water rippled beneath them, and they both looked back down at Karai whose body shuddered and arched, shrinking and darkening. Her tail split in two and became legs. The snake-head hands shrank into human hands, and short hair protruded from her head which then acquired a human face.

"By Darwin's beard," Donnie said, gaping as they watched Karai transfigure back into Karai and then go still again, lying on her back in the sewage, head to the side.

"But … But …" Donnie stuttered. "But how—"

"She's not human yet," Leo said, moving closer to her. He picked up her arm and draped it around his neck then scooped her carefully off the floor. "We need to get her back to the lair … Preferably before she comes to."

Donnie, though obviously stunned, set his jaw and nodded.