Leo makes his way out to the barn so he can talk to Donnie privately. Walks. Not limps. He is not limping, no matter how much effort it takes to not favor his right leg. Even so, it's hard to keep control, and he bumps into a stack of crates by the entrance to the barn, which makes Donnie jump.

"Mikey, how many times have I told you—oh! Leo!"

"Hey, Donnie." Leo advances, and takes a seat on the other stool. Carefully. Not rushing, like he needs to sit down as soon as possible.

Donnie faces him with hands twitching at his sides. "Did, um, did you need something?"

"Yeah. I need you to tell me what's wrong with my leg." It's not getting better—or it gets better and then gets worse again—and Leo needs to know.

"Well— well, I can't be certain, I mean, with what we've got here—" Donnie waves his hand vaguely at the barn around them. "I'd need equipment, like real equipment, to tell for sure, so there are a number of possibilities, and I'm not—"

Leo cuts him off. "You must have some kind of theory, though. Give me your best guess, that's good enough for now."

Donnie blinks and fidgets with the paper on the workbench and looks anywhere but at Leo. "Um... it might be a tear to the anterior—"

"In simple words, please."

They'd all studied basic anatomy, so Leo expects Donnie to flare up and remind him of that fact, but instead his shoulders hunch, and he wilts, saying, "Look, you remember there's a pad of cartilage cushioning the leg bones inside the knee, right? And several ligaments that stabilize the joint."

"Right." Leo does remember, and he has a feeling he isn't going to like what Donnie says next.

"So my best guess is you've injured one or more of those ligaments, or even the cartilage. Could be a partial tear, could be more. There's no way for me to tell without some kind of scan, and we just don't have access to the right kind of equipment."

No. Leo definitely doesn't like that. "So what does that mean? When is it going to get better?"

Donnie opens his mouth and shuts it again, eyes shifting. Leo narrows his eyes. "Donnie. Tell me what you know."

"I don't know!" Donnie spins around on his stool and then pushes himself off it, pacing in long strides. Leo watches with more than a pinch of envy. "It's not a fracture. You had some of those, too, and we set them and they healed. I'm— nearly certain we s-set them correctly, and you were resting the whole time. Those healed. Ligament damage could take— I don't know. A long time. You can put weight on it, so it's probably a partial tear. It'll heal, but... slowly. Humans would get, um, surgery for something like this, but I can't— it's too risky, especially without knowing what's actually wrong, and we don't have anything we need to do it safely, I'm not even sure we can create a sterile environment around here, and I don't know how to—" He spins around on his heel so he's facing Leo, but his eyes are fixed on the floor. "I don't know, okay?"

"Your best guess," Leo says again. Sometimes you have to do or say something to shake Donnie out of the spiral of his own thoughts.

Donnie throws his arms wide. "I don't have a best guess! I—" He stops himself and takes a breath and finally looks Leo squarely in the eye. "Worst case: it's always going to be weak. It may never get better, and it might get worse as the cartilage wears away. It'll always be vulnerable to re-injury." He takes in the look on Leo's face and adds hastily, "It's been improving, though, so maybe it's not as bad as it could be. Maybe it'll be better in... I don't know, a few months?"

It's obviously a guess, and not even a great one, but Leo nods. This was what he asked for, and no matter how bitter the news is, he has to figure out how to deal with it. Months, though... "That's too long, though. We can't stay up here forever."

Donnie shrugs, hands spreading helplessly. "I know that, but I don't think there's any way I can speed it up. I mean, I could keep messing with the mutagen medicine..."

Leo grimaces. "I'll think about it."

"Keep it wrapped for support." Donnie's voice has gone soft and toneless. "Ice it to keep swelling down, heat if it feels too stiff. Alternate them. Rest it. Don't push things too hard. It's easy to injure it again."

"That's not good enough," Leo mutters, more to himself than to Donnie, but Donnie answers anyway.

"I don't know what else to tell you, Leo, except... I'm sorry."

There's too much packed into the last two words, and when Leo looks up, frowning in confusion, Donnie is staring at the floor again, shoulders slumping. "I'm sorry," he says again. "It's my fault, I shouldn't have argued with you or—"

"Well, you were sort of right." Leo stretches out his bad leg, carefully. "We really didn't have time to scout out locations outside the city."

"No, but you were right!" Donnie says. "The Turtle Mech was too much, and even then it wasn't enough to stop Kraang Prime, not totally, and if I hadn't argued with you and slowed us down, we wouldn't have had to split up and then you wouldn't—"

"Donnie. Donnie, hold up." Leo remembers the argument, but it hasn't exactly been at the forefront of his mind, with how everything else has gone. He remembers being angry about it, but the emotion already feels old and faded. "Have you been thinking about that this whole time? All these months?"

Donnie stares at him, and Leo doesn't know why he bothered asking the question. Obviously Donnie has, and Leo should have known he would. He was there, after all, when Donnie beat himself up over Metalhead, and the Pulverizer, and Mr. O'Neil. He tries for a reassuring smile. "It's okay, Donnie."

"It's not," Donnie says. "It's my fault you're—"

"I'm what?" Leo knows his own tone is sharper than he would have liked. There have been enough words floating in his own head. Crippled, and weak, and useless— what kind of ninja can barely even walk without limping—

Donnie's mouth twists. "—hurt."

"Pretty sure it was the Shredder and his people who ganged up on me." Leo fights back a shudder. He stills sees it in his dreams: the Shredder silhouetted against a turbulent sky, watching him with pitiless eyes. Sometimes Karai is there, too, sometimes it's just the others, but always someone, watching, watching, cold and still and judging while he struggles. Even now, the thought of it makes him tense up, breathing harder.

There's a hand on his shoulder, solid and comforting, and Leo looks up to find Donnie peering at him with anxious dark eyes. He attempts a smile again. "So, you know, don't— don't blame yourself."

"I am sorry, though," Donnie says. "I'm sorry I fought you, and I'm sorry you went through that alone."

Leo flinches again. His brothers haven't asked too many questions about exactly what happened, and he hasn't felt much like telling them, beyond that it was the Foot. Would they have done better if they'd stayed together? He thinks about walls, endless walls, closing in, and wave after wave of Foot bots, and the arrows. "There were too many," he says. "Even with all of us—there would have been too many. They were ready. They'd— I think they'd planned it." Only in saying it does he realize how true it is, and it feels like he's expelling something sour from his chest and gut. Donnie's grip tightens on his shoulder, and Leo adds, "Besides, you were already hurt."

"Yeah." Donnie touches his scar with one finger; it's half-hidden under his wrist wraps, a welt that's a darker green than the rest of his skin. "Still, I screwed up, and I wish..."

When he doesn't continue, Leo says, "Maybe— I think we both made mistakes that day. The Kraang were prepared, and the Shredder was prepared, and we weren't. Not enough, anyway. But at least we made it out." This time his smile doesn't feel like a struggle. "Thanks for taking care of me all those months."

"Of course," Donnie says. "I mean... of course we weren't going to give up on you. I just... I wish Sensei were here."

"Yeah," Leo sighs. A little part of him is selfishly glad he didn't have to see their father fall, like the others did. He straightens his knee again, testing it, feeling for the little pull or click that's become too familiar. It comes, right where he expected it, and he grimaces.

"Maybe you should put some heat on it," Donnie says.

Leo nods, and holds his tongue when Donnie helps him off the stool. He doesn't need it, really, but it doesn't hurt, either. "I might need to learn to compensate for it," he says once he's on his feet. "While it heals, at least." He's not willing to give up on the idea that it's going to heal, not yet, though he's not going to forget Donnie's worst-case scenario, either. "You're all going to need to help me with that." Again, and it stings a little—they've already done so much—but not as much as it could have.

"You know we will," Donnie says. They're close enough to the house to hear voices, Raph and Mikey and Casey all arguing at once. Leo rolls his eyes at the noise and Donnie smiles back at him.

His leg still hurts, twinges on every step, but Leo takes the steps on his own. Not limping. He just has to learn to adapt, like Sensei always said. It's not much of a plan, but it's what he's got.