This came from talking with my sister and boyfriend while I was trying to think up ideas for more TMNT fanfics. I'm not sure how it came about to be honest.

This could be considered a part of the 2003 4kids series due to mentions of the Ancient One, but I like to think of it as part of the 2007 movie verse. But it's most likely the 2003 series.

Disclaimer: I do not own the Ninja Turtles in any way shape or form.

0-0-0-0-0-0

It was a rare opportunity to be allowed to watch the turtles spar as Splinter really didn't like others watching, even those such as the Ancient One, the one time he visited. So for April O'Neil and Casey Jones to be allowed, they said nothing and weren't about to look a gift horse in the mouth.

However, when Splinter told his sons that they were going to work on their skills fighting blind, the two humans were confused when Donatello came and sat with them, looking as if leaving his brothers instead of joining them was normal.

"Um..." Casey started, unsure of what to actually say.

His best friend, Raphael, grunted and said, "Donnie don't need to work on his skills fightin' blind."

"Donnie's the best at it," Michelangelo continued.

"I'm not the best," Donatello said, trying to downplay his skills.

It was Leonardo, of all people, who gave him a look that clearly told him to stop lying.

Casey and April didn't get a chance to elaborate before all three turtles turned their masks so they were blindfolded and training began.

Throughout the entire process, April noticed that Donnie was watching carefully, as if making note of what his three brothers were doing wrong.

When training ended and the four turtles and two humans were in the main/living room, April asked, "Mind explaining what you meant earlier?"

"When we spar blind, Leo, Mikey, and I are all on our shells within minutes. It's been that way since we were kids. Donnie's just too good," Raph said as he leaned back into the couch, arms propped over the headrest.

Mike frowned, thinking about that, before he said, "By the way, Donnie. I've been meaning to ask, but never did: how do you do it?"

Now Raph and Leo were looking at him expectantly.

Rolling his eyes, he answered that with another question, "What are you thinking about when you're fighting blind?"

"I'm trying to figure out where to put my feet and not knock into anything," he answered.

Don looked at Leo and Raph, silently asking them the same question, and Leo answered, "I'm thinking about how to do it."

"I'm with Mikey," Raph said.

"There you go. You're thinking. When I fight, I turn that off, basically. I stop thinking and start listening. I don't know if you've noticed, but when you're fighting blind, your other senses enhance to make up for that, especially hearing. I don't think about anything: I just focus on listening. Each of you are focusing on something different. Not only that, but I... expand, for lack of a better word, my senses so that I can sense where everything is, even though I can't see it. I can actively tell where everything is, even when it changes positions in the room. Remember when Sensei had us do it in the living room in the old lair, twice? Even though things had changed from the time between the first time and the second, I could still do it because I could sense where it was. I don't know how I do it, I just do. Just like how Leo does mediation, which, out of the four of us, I suck at," Donnie explained patiently.

All five were quite, thinking that over before Leo said, "Mind showing me?"

Donnie nodded and all six went into the dojo so that Mikey, Raph, and the two humans could watch.

Donnie turned his mask around and readied himself as Leo unsheathed his katanas.

They all watched carefully as Donnie clearly relaxed, not at all tense as he held his Bo in his hands.

Then, without warning, Leo attacked.

The attacks came at him over and over, but Don easily blocked them and returned with strikes of his own, hitting Leo at times.

April frowned, thinking, "Don's fighting style has changed a little. I wonder if he or the others have noticed."

Looking at Mikey and Raph, she could tell that they had noticed, which meant that Leo had as well.

Finally, the eldest turtle said, "Enough."

Don hopped back and turned his mask back around as Leo said with a frown, "I never noticed since we were all blindfolded, but your fighting style changes slightly. Not by much, but it does."

To their surprise, Don only nodded as he responded, "That's because when I'm blindfolded, I hear everything. I can hear hear you moving and I adjust myself to reflect that. I can even hear Sensei in his room, breathing as he meditates when blind. I can also hear the low humming of the arcade games. And because I'm hearing everything, I have to sort it all out as if I'm a filter. When I do "filter" it out, I can still hear it, but it's not on my radar, so to speak. I focus on what's around me and what be coming towards me."

"How so?" Leo asked, intrigued.

"Well, say I was fighting you and Raph was just coming into the lair. I hear it, but I ignore it. I can also hear and sense him coming our way to scare Mikey, who's playing an arcade game that's next to the dojo. Raph's using the stealth that we were all taught, but I still sense him and hear him."

Donnie shrugged self-consciously as he finished, "I don't know how I do it, I just... do."

"Well, it finally makes sense about the last time that we were fighting Shredder and you ended up kicking his butt. But your mask wasn't blinding you that time," Mikey said.

"I had been pepper sprayed by one of the slightly smarter Purple Dragons," the purple banded turtle answered.

"Mind trainin' with us a bit more, Brainiac? To help us get to yer level?" Raph asked.

Mikey and Leo nodded, looking at him expectantly.

Don blinked in surprise before a wide grin broke across his beak and he said, "Sure!"

As the brothers and friends continued to talk about fighting blind and how Don could help them, April couldn't help but wonder what other surprises that Don had in store and was waiting to be discovered by his brothers and two friends.

0-0-0-0-0-0

As I'm not a martial artist in any way, I don't know if this is actually possible or not. I just like the idea of Donnie being so badass at fighting blind that even Leo can't match him :D