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Sleep was a luxury he could no longer afford, apparently. Leo sat up from his bed after fruitless hours of trying.
It had been weeks since the episode with the mutant fungi, since the effects of those spores had worn off and the edge of sheer panic that laced his dreams had turned into a dull throb. Still, something had to be said for subconscious self-preservation. Rather than awaken gasping, he simply didn't fall asleep. Now, he'd collapse from sheer exhaustion every so often, insensate to the world, and then he'd wake up to start the cycle all over again. It was getting to him and Master Splinter had noticed, pinning him with a particularly intense gaze. A talking-to was forthcoming, Leo could feel it.
In truth it hadn't been the spores for a while now, Leonardo had enough fuel for his nightmares. What he'd said to that one-eyed freak was true. He did face the fear of losing his team, his family, every single day. And with every close call, Leo could feel his nerve slipping.
This last time, it had been Mikey's turn to be badly hurt. Some idiot purple dragon had gotten lucky with a knife and nicked his arm in the wrong place. Then came the blood. Too much of it. Had it not been for Donnie and April's quick thinking... Leo shuddered to think of the consequences. The image of his brother, pale and supine in some dark alleyway, surrounded by enemies, propelled Leo off his bed and out of his room. His heart thundered and he braced himself on the wall to steady his swimming head.
Deep breaths Leo, he told himself. Cleansing breaths. A nervous chuckle surged out of him, sounding distorted and wrong in the silent lair. He shook himself and inhaled deeply through the nose. The bitter scent of coffee filled his nostrils.
"Donnie."
Warmth curled into Leo's chest. Normally he'd be upset at his genius brother for being up at this hour, but lately he'd come to appreciate what it was like to have an uncooperative brain.
Still unsteady on his feet, the turtle made his way out of the tunnel and down the steps into the common area. Light poured out from underneath the laboratory's door on the other side, drawing Leo forwards like a moth. When he pushed the door open, however, he found a blank computer screen and an empty chair. Sniffing the air more carefully, he realized the scent was coming from the kitchen.
This time he succeeded. Donatello was sitting on one of the benches, a half-drained mug of steaming coffee in one hand, his head cradled in the other. Leo made sure his steps were heavy, not wanting to startle his brother. Donnie still jumped when he pulled up a chair next to him.
"Rough night?" asked Leo, taking in the drooping of Donnie's eyes, his sagging posture.
"Yeah," was the only answer he received.
"Hit a wall?"
"Something like that... I guess."
Leo pursed his lips, dragged himself closer and winced at how the scraping chair broke the deep silence around them. "Sometimes you're worse at lying than Mikey. What's wrong?"
"Why does something have to be wrong?" came the clipped response.
"You haven't even looked at me" Leo deadpanned. That was what finally made Donnie turn to face him and oh, it was worse than Leo thought at first. His eyes were red (though not puffy, thank heavens) and his brow had that pinched sort of look it got when he was about to get one of his famous raging migraines. His throat was working now and he wrapped his arms around himself, looking away from his brother.
Leo's brows shot up, he couldn't help feeling offended. Donnie could be the most reticent of his siblings, if the mood struck him, and it was true that they never spoke much, but that was only because they seemed to operate on the same wavelength anyway. Whatever this was, though, it clearly had him on edge. Now wasn't the time for silence and Donnie knew this. Leo put on his best leader face and leaned into Donnie's field of vision, staring hard.
One glance, then two, and his brother crumbled, sighing out and looking for all the world like he was in physical pain. Leo ignored the twinge of guilt and waited patiently for him to gather his thoughts.
"Okay, remember how I've been storing blood from all of us? Just in case?"
How could he forget? After that incident with Mikey, they'd all been hit with the reality of how ill-prepared they were to handle serious injury. It's not like they could just walk into the nearest hospital and ask for mutant turtle blood, for starters. Leo simply nodded, not wanting to interrupt his skittish brother.
"Well I ran some tests on our different blood samples, you know, to determine if our antigenic- uh... I mean... If any of us are the same type." More nodding from Leo. The pained expression returned with full force. "I found... Well I found something I wasn't looking for. About our DNA. Leo we... we don't match."
"What, we're not the same type?" That was it? That's what had Donnie so worried? Leo huffed out a laugh that was half annoyance, half relief. "I mean sure, it limits the options for a transfusion but that's why you've been taking blood from all of us."
"It's not just the blood, Leo," Donnie dragged a heavy hand over his face, pulling his mask askew, "Nothing is the same, the genetic makeup for each one of us is different. I mean really different."
A pause, then-
"Wait, are you saying-"
"Collectively, there are two different strains of human DNA present, and three different combinations of turtle DNA. Not a single one of us is the same combination as any other."
Leo wasn't sure at what point he'd risen out of his chair, but now he sank back heavily.
"Two different- but I thought that Master Splinter- That Hamato Yoshi-"
"He's one of the two!" Donnie cut him off, raising his hands in a placating gesture, "As for the other? No idea. It could've been a kid who picked us up at the pet store, the store manager when they handed us off to Yoshi. It could've been anyone, really."
Leo nodded, as though he understood, as though any of this were making the tiniest bit of sense. His mind latched on to whatever could continue the conversation, pull them out the other side.
"And the three turtles?"
"Not three turtles per se, three different sets of parents, therefore three combinations."
Leo frowned, "Among the four of us? But that would mean-"
"That only two of us are related on the turtle side, so to speak," Donnie finished for him.
Leo had gone from nodding, to shaking his head now. This was too much, all at once. There was something nagging at him though, like a stone caught between his scutes.
"Donnie, do we all have Splinter's DNA?"
He regretted the question as soon as it left his lips. He snapped up to face Donnie and retract it, but the beaten expression that greeted him was answer enough.
"Oh man," Leo sighed, dragging a hand over his head, wishing he had his mask on so he could pretend to adjust it or something. "Don't tell me who, I don't want to know. It's bad enough that you do."
A wan laugh from Donnie drifted up between them and they finally looked at each other again. For a while they just sat there, breathing, processing. Leo could see everything he was feeling reflected in those mahogany eyes; the confusion, the hurt, the uncertainty, and it was all giving way to rising panic.
It had to stop.
"Listen," he started, "This doesn't mean anything."
It was the wrong thing to say.
"Doesn't mean- Leo! Didn't you hear a single word I just said? Of course it does! We're not related to Splinter, we're not even related to each other!"
"So what," Leo was very aware of getting out of his chair this time, "you're saying we're not brothers? That having grown up together doesn't mean a thing? Who found us, Donnie? Who took us under his protection, fed us, taught us all these years?"
"Splinter, I know but-"
"Blood doesn't matter! That's not what makes us family."
"Well then what does that say about Karai?"
Leo froze, blood draining from his face, but there was no stopping Donnie now that he'd latched on to an idea.
"You keep telling us that she's Splinter's daughter, not Shredder's. That it doesn't matter who raised her because she's Splinter's blood. So which is it then? Is she family or are we? You only think blood matters when it suits you!"
Leo reeled like he'd been punched. He swallowed hard against a distinct tightness in his throat, nodded with a grimace and moved to turn away.
Donnie started after him. "Ah, jeeze, Leo I-" but Leo held his hand up to stop him.
"It's fine-"
"No it's not, I didn't mean to-"
"Don, really! I don't have answer to that. I can't-" He scrubbed a hand across his face. "I can't tell up from down anymore when it comes to her. All I know is that Splinter cares. When he looks at her he sees his daughter and he's our- I can't think about her any other way now." He saw Donnie reach for him but the touch never came, so he continued, failing to keep bitterness out of his voice.
"I also know that I have a father and three brothers and your results aren't going to change that."
He turned away in earnest this time, but a hand caught his wrist in a vice-like grip. Leo rounded on its owner, expecting the fight to continue, but the fear written on Donnie's face was enough to stop him.
"You're right," Donnie said, voice shaking but urgent. "You're right, I'm sorry. I panicked. I was scared, but you're my brother and... I-I don't know what I was thinking, I'm sorry!"
Leo sighed tiredly but he put his free hand on Donnie's shoulder, wincing when it made him jump.
"I know," was all he said at first. Then, "This is freaking me out too. But I mean it, this doesn't change anything unless you let it."
"I won't," Donnie replied, suddenly vehement, and it made Leo sag with relief. He suddenly felt very tired.
"I think I'm gonna head back to bed," he kept his tone gentle and a smile on his face, "I think you should too."
Donnie nodded, but his own smile was tight and he seemed no lighter than when Leo first found him.
"Good night, Leo."
"Good night, Donnie."
Leo turned away with a wave, aware that Donnie was still simply standing there, not knowing what to do about it. The walk back to his room was a blur, and the sight of his rumpled bed was still not a welcome one. He knelt on it, tugging at his covers mechanically and trying to settle the roiling emotions at the pit of his gut. Some sense he hadn't yet put a name to kicked in and Leo stopped and turned, only to find Donnie standing, contrite and a little forlorn, at the door to his room. The tall turtle took a tentative step forward and then retracted it, hands reflexively reaching to tug on the strap of his holster even though he wasn't wearing it.
Leo tried his best to hide his grin. He knew exactly what Don wanted, and how hard it was for him to ask for it. They were sixteen after all, not six.
"Come here," he said, scooting over towards the wall. Donnie looked affronted for a moment, and Leo turned away, leaving the empty space as an open invitation. He didn't have long to wait. Soon the mattress sank as Donnie lowered himself onto it, not saying a word.
Too much time had passed since they'd last done this. His bed was the same but he was bigger, and Donnie was even more so, all gangly limbs and sharp edges. Leo tossed around a bit as well until he ended up on his stomach with one of Donnie's long arms thrown over his shell and a knee poking at his shin. It wasn't exactly comfortable but his brother was there, warm and heavy and with his mask still on, pretending to be asleep already so his pride wouldn't suffer.
And really? Nothing had changed.
Leo smiled as he plucked off the purple mask, snuggled down, and was swallowed by a dreamless sleep.