An annoying tone jangles in Leo's ear, and for the umpteenth time, he tears off the headset Donnie had given him and throws it on the floor.

For the first time, Donnie doesn't immediately nag him to put it back on.

(How Don always knows that Leo has taken the headset off, Leo can't figure out. But then, he can't figure out how Don knows most of what he knows.)

The electronic tone continues to sound faintly from the discarded device, and after a few repetitions of the short melody, Leo realizes that is Don. His brother is calling him.

He stoops, picks up the headset, and fits it back over his ears.

"Hello?"

The irritating little song keeps playing.

Leo feels for the tiny button on the outside of the earpiece, and presses it.

"Hello?"

"Oh, Leo," Don says, as though he hadn't expected to find himself speaking to his eldest brother just at that moment. Leo is so used to the nerd's mannerisms that the inexplicable surprise doesn't even register. He's just glad to have exchanged the grating ringtone for his brother's voice. "We have a situation."

"Why are you calling me, Donnie?" Leo asks. He lowers his hand from the earpiece and cups it with the other in his lap, furrowing his brow as he stares across the room. It's weird to be talking to someone without looking at their face. Even though he trusts Donatello completely - he would do any number of things for his little brother, and actually has done an alarming variety of things he never even would have thought to put on that list - it makes him feel uneasy to be talking to anyone without being able to read their expressions.

"I just told you," Don says. "We have a situation."

Leo rubs his brow. His fingers bump against the plastic band of the headset, and he fights the reflex to tear it off and throw it on the floor again. The gear bothers him, in a way his mask and scabbards never have. He doesn't understand how Don puts up with being practically encased in the stuff. "Don," he says carefully. "Why didn't you just walk over here and talk to me?"

An awkward pause. Never a good sign with Donatello. (Some things, Leo doesn't need to see his brothers in order to read from them.) "You know I'm not home, right?" Don says.

Leo's eyes snap up, and his uncovered ear scans the Lair. It's quiet, but unlike with Mike and Raph, volume levels are never a reliable indicator as to Don's presence or absence. In some ways Don is a born ninja, fading into the background through what some would call a lack of personality, but which Leo prefers to describe as the gift of invisibility. Donnie has plenty of personality; he's just innately free of the need to advertise it all the time. "Why didn't you tell me?" Leo demands.

"I did!" Don replies indignantly. "I messaged you on the way out. Didn't you get my text?"

"Donnie, I don't even know what that is." Leo's voice rises and so does his body; before he knows it, he's standing up and pacing. Why can't his brilliant brother leave a note on the fridge like a normal person? Why couldn't he just tell someone his plans face to face? And why is Leo too dumb to know what a text is? His family is trying to communicate with him, and he's too disconnected to hear them.

"I guess that answers that," Don says. "Anyway," he goes on, circling back to the point his audience understood, "I'm not home."

"Right," Leo says, calming himself through an effort of will. He'll meditate on his failures as a brother and a jonin later. "And you have a situation."

"Exactly," Donnie says, delighted to learn that Leo understood that point too. "You see, I got in a fight with a mattress, and it kind of broke my glasses."

The battle to remain calm takes a sudden turn for the worse. "Are you kidding me?" Leo says. He is so wishing that Donnie were here right now, so he could give him an outraged look, or maybe even strangle him a little. These telecommunication systems Don is so in love with are not a remotely adequate replacement for real communication systems.

"I misstated that," Don says. "My glasses are really broken."

"A mattress?" Leo shouts, and out of the corner of his eye he sees Raph poke his head out of his exercise alcove, to see why his older brother is yelling about home furnishings.

"Well, I was trying to salvage the springs," Don explains, "when one of them sprung unexpectedly. Got me right in the face. I'm pretty sure I stopped bleeding, but the released tension shattered the frames and one of the lenses. What are the odds? I mean, I could calculate them, but for once I really don't want to know."

Leo drags a hand down his face. "So let me ask again, Donnie. Why are you calling me?"

"I need you to look at the feed from my shoulder cam and guide me home," Don says, as if he's put a great deal of thought into this. Between that and Don's comment about having stopped bleeding, Leo wonders how long his brother has been sitting out there, blinded and lacerated by a piece of bedding. How long ago had Don left home?

"Why don't you just navigate with your gizmos?" Leo asks. Raph has jumped down from the alcove to give him a penetrating look from close up. Leo waves him away, but Raph doesn't retreat.

"My display?" Don asks. "I can't see it."

"What do you mean you can't see it?" Leo demands. "It's huge and two inches from your face, Donnie."

"I can't see it!" Don's voice is rising in both pitch and volume. He never, ever complains about his low vision, but at rare moments like this, Leo is reminded how scared Don is of his disability. "I knew I should have made a tactile display, but I never got around to it!"

"Okay, okay," Leo says, trying to keep Raph out of his personal space and comfort Don at the same time. "Tell me where you are. I'll come get you."

"I - I need to do this, Leo," Don says, and there's the steel that always follows his fear. "What if this happens someday and I'm too far away for you to get to me? We should have done this as a training exercise, but -"

"I know," Leo says. "That's my fault." He sidesteps the question of why Don would ever be too far away for his brothers to get to him. As far as Leo is concerned, that distance would be measured in lightyears. He sets that aside, and refocuses on the problem at hand. "Tell me what I need to do."

"You need to turn on the feed from my shoulder cam," Don says.

Leo waves his hands the way he's seen Donnie do countless times in the past years - tentatively at first, then confidently, then with the same automaticity he'd use to interact with familiar physical objects. But no holographic display bursts into existence.

"How do I turn on the display?" he asks.

"What?" comes the response. That's a rare and worrying answer from Donatello, and Leo revises his estimate of this mission's chances of success in a downward direction.

"The headset's display, Donnie," Leo says. "How do I turn it on?"

"Oh, it doesn't have one," Don says. "It's just a headset."

Leo presses his eyes closed, trying to keep his composure. "Donnie, since when do you build anything that's just that thing?"

"Well, I simplified it for you…" Don says in a small voice.

The words go through him as if Donatello had just shouted "Baka!" at the top of his lungs. He'd simplified it, because Leo is too dumb to muddle his way through the technology his brother wears like a second skin. Once again, he's letting his family down.

"You need to turn on my mainframe," Donnie is saying, and Leo almost misses it because he's too busy berating himself. Another failure.

Leo starts moving immediately, only to realize he doesn't know which direction to go. "Which is your mainframe?"

"Oh," Don says. "That's kind of hurtful." A pause just long enough for Leo to give himself more demerits for not being able to identify objects of great importance to the people he cares about most. "It's the big one on my desk. You need to wake it up from sleep mode. Just hit any key." Another pause as he reconsiders that instruction, and judges it too difficult for Leo to follow. "Press the button with the letter A on it."

"You gonna tell me what's happening?" Raph demands, as Leo strides towards the mass of monitors Don often ensconces himself in, connecting himself to the information flow of the world without ever leaving their home.

"Don broke his glasses and can't get home," Leo says, as he punches at the big letter A on the rack of buttons on the desk. The buttons seem too big for normal fingers, and it's always mystified him that humans don't make smaller ones. "I need to navigate for him."

"Yes, I know that," Don says in his ear.

"I'm talking to Raph," Leo explains, disoriented by the dual conversations. He's never understood how Don does this either.

"Oh," Don says. "Hi, Raph."

Raph doesn't respond to being greeted, and it takes Leo a minute to realize that Raph can't hear the other conversation. "Don says hi," he relays.

"Are you logged on?" Don asks, before Raph can say anything.

Leo doesn't know how to answer that, so he says, "There are pictures on the screens."

"Okay," Don says. "I'm going to remote in to Master. Tell me when you see a different picture." There's a brief pause, and then Don speaks in the commanding tones he only uses with machines, never with people. "Cast Hackwrench to Cerebro. Access code 20-13-14-20."

For a moment nothing happens. Then the central screens flicker into a grayscale feed of what looks like a garbage dump, while the peripheral monitors continue to show news programs, views of the sewers surrounding their home, and strings of numbers whose relevance Leo can't begin to guess.

"Got it," Leo reports.

"Good," Don says. "Hold on. Transfer call from Blue Hat to Cerebro. Raph, can you hear me?" And suddenly his voice is coming out in stereo.

"Yeah, I can hear you," Raph says, and with unusually slow and cautious movements, Leo takes off the headset and places it on the desk.

"Donnie, are you still there?" he asks, unsure where to direct the question.

Don's omnipresent sensors must pick it up, because he replies in the affirmative. "I hear you, Leo."

Leo leans close to the monitors. The image is jiggling around as the camera rises and falls with Don's shoulders, with his breath. "Donnie, where are you?"

"I'm on a garbage barge," Don says. "I know how to get home from here, but I need you to help me find a safe path."

"How are you going to get off the barge?" Leo asks, sensing a serious flaw in the plan.

"See, that's the problem," Don says, confirming Leo's suspicions. "All my gear automatically turns off when I'm in the water. I need you to point me in the right direction, and then I'm just going to have to swim for it."

Leo pinches the ridge between his eyes. "Donnie, are you sure you don't want us to come for you?"

"I can do this, Leo." The image shifts, everything moving downward, and Leo realizes Don has just stood up. "Which way am I facing?"

Leo studies the screen, but all he can see are piles of garbage and indistinct buildings in the background. "I don't know, Don," he says. "Turn on your navigation system. I'll read it for you."

"The hologram will be out of sync with the camera," Don says. "You won't be able to see the display."

Leo doesn't understand the explanation, but he trusts the statement. "Okay," he says. "Can you walk around a little? Help me get my bearings."

"I'm somewhere between Greenwich Village and Hoboken," Don reports, as the camera pans around.

Raph snorts. "Why?"

"Because this is where the garbage barges go?" Don replies. "I mean, are you asking for a history of landfill siting and trash removal in the Tri-state area?"

"Hell no," Raph says quickly. "Hey, stop."

Don stops. "Which way am I facing?"

"Well, one side or the other." Raph squints at the fuzzy buildings, and so does Leo. "That's gotta be the New York side."

"Don't send me to New Jersey," Don says. "I'll never forgive you."

"Yeah, yeah," Raph says. "Walk to the side of the boat, genius."

"Barge."

"What's the difference?"

"Don't answer that, Donnie," Leo interrupts, before Don can launch into an explanation of different types of watercraft. "Stop a minute. Why is this video so grainy?"

"Sorry," Don says. "It's on night vision. This is as good as it's going to get."

Leo reins in his frustration, and tries to appreciate what a gift it is to be able to open one's eyes and see the world clearly. "Don, let me see you."

A pause. "Why?"

(Faces meant little to Donatello. The first time he had put on a decent pair of glasses and seen his brothers' faces clearly, he had cried - not from happiness, but because he couldn't tell which of them was which. To him, they were a voice, a pattern of movement, a distinctive shell texture, not a collection of facial features. It was distressing to him to finally see his family, and not feel an instant sense of recognition.)

(And, Leo had only realized much later, having never seen his own face properly, Don hadn't known how monstrous they were. He'd been frightened by his own brothers' appearances.)

"Just do it."

"Um, okay." The image shakes nauseatingly as Don detaches the camera from its harness and turns it around, holding it out at arm's length.

It's strange to see his brother pixelated and drained of color, but Leo studies the image closely. There's a jagged scratch running right across Don's face, mercifully missing his eyes and sparing what little vision he has. His techno-goggles are perched on his head, but his glasses are gone. Presumably whatever's left of them is packed away in one of Don's pouches. He's looking in the general direction of the camera, yet not quite connecting with its gaze.

"What the hell happened to you?" Raph says, both alarmed and impressed at the clotted wound on his little brother's face.

"Can we talk about it when I get home?" Don says, hurriedly turning the camera away and fastening it back in place. "We're wasting darkness."

"Right," Leo says. "Donnie, keep walking to the edge of the barge."

"Can't see it," Don reports, as he feels his way forward. Before he got his glasses, Don had navigated with such limited visibility that blindness training was nearly unnecessary for him. In some ways, he's more comfortable in pitch blackness than with the lights on. He's also well-used to his brothers steering him. But none of that means that he goes confidently striding forward when he knows there's an edge nearby.

"Neither can I," Leo says. "Go slowly."

Don reduces his pace another increment, navigating himself around another heap of garbage. The image quality is too poor for Leo to identify any of the refuse, and he worries again about this plan.

"It'll be fine once we get him in the tunnels," Raph says, reading Leo's thoughts.

"He's a long way from an entrance," Leo points out. "The manholes on that side of town are too small. He'll have to roof it at least as far as Midtown."

"Guys, can we limit the side conversation?" Don says. "Jumping off this blind is going to be not-fun enough if I'm ready for it."

"I can see the edge now," Leo says, refocusing on the screen. "Ten feet."

Don counts his paces - Leo can tell, even though it's been a long time since his brother has needed to do it out loud - and then the camera angle shifts as Don crouches to feel for the low rim of the barge.

"Got it," he says, and Leo can see his gray hand closed around the fold of metal before the camera tilts up again.

"Just go straight ahead," Leo says. "We'll pick you up on the other side."

"Okay," Don says. "I'm going to turn everything off. I'll be back in a few minutes."

And before Leo can say anything, the screens go dark and the phone connection cuts out.

While Don is gone - swimming blind, deaf, and alone across the dark Hudson - Leo fills Raph in on how they got here. Raph howls with laughter when he hears that Don is in this predicament because of a mattress, and promises that he will never let their little brother live this down.

"Real mature, Raph," Leo says, and then the hated ringtone is coming out of the computer, and Leo doesn't know which button to press. Raph hits a button seemingly at random, and then the screens are showing Don's sneakers in front of the lapping river water.

"Well, I made it," Don says. "But now I don't know where I am."

"Can you show us a street sign?" Leo asks.

"I'm outside 11th," Don says, referring to the street that ran along Manhattan's western shore. "I'll try to find you a pier number."

He stands up from the sand, and in short order has flipped himself on top of the pier he had paused under. He zigzags in and out of the shadows, hiding incompetently, too unable to see to judge whether anyone else could see him.

"Stay left," Leo says, and Don obeys. Leo feels strangely tiny, riding on his brother's shoulder in this way. At the same time, it's deeply satisfying to micromanage Donatello's movements, directing his every step. He's sometimes wished he could step into his brothers' bodies, to make the right moves for them and keep them safe, and as Don walks along the quiet pier, Leo thinks this is as close as he'll ever get. Until Don invents an actual mind transfer device, at least.

"Bogeys ahead," Raph says, and Don crouches in the shelter of the shipping containers Leo had guided him to.

"I can hear them," Don says quietly. "Dock workers." A soft inhalation of breath. "Smoke break."

"Wait them out," Leo advises.

"Negative," Don replies.

"Take 'em out," Raph suggests.

"What?" Don says. "No." Effortlessly, soundlessly, he pulls himself up to the top of the shipping container, and points his camera towards the foot of the pier. "Plot me a course."

Leo studies the maze of shipping containers, and names a sequence of moves that should carry Don safely across them. The bottom drops out of his stomach, though, when Don takes his word.

"Here I go," Don says, and the bottom of Leo's stomach comes back up forcefully, trying to eject whatever's sitting on top of it, as the image on the screen rushes and spins across the corrugated landscape. Don is taller than Leo, faster and more agile; the way he covers ground is different from how Leo would have covered it, even with the same moves. At the risk of making himself sick, Leo keeps his eyes on the screen - and it's a good thing he does. A split second before it's too late, he can see that Don is going to overshoot the last landing pad.

"Pull back!" he shouts, hoping it's still not too late. "Pull back!"

Don checks his speed and shortens his last jump, hitting the metal roof hard and clumsy. He rolls over his shoulder to kill the last of his momentum, then comes back to his feet.

"Are you okay?" Leo asks.

"Um." Don pauses, running what he calls his organic diagnostics. "Yeah," he says. "Nothing broken. That wasn't already."

Leo presses the heel of one hand into his eye. "Please tell me you don't have injuries you forgot to mention."

"I said I'm fine," Don says shortly. He points his camera over the edge of the shipping container. "Am I clear?"

"You're good," Raph says, because Leo just can't right now.

Don lets himself down and presses his shell against the side of the container, pivoting slowly to give his brothers a view of the area. "Do you see a sign?"

"Yeah," Raph says, "but I can't read it. You gotta get closer."

"Hold on," Don says, and the image joggles for no apparent reason. "Right or left?"

"Back to the left," Raph says.

"Tell me when," Don says, and the image pans back the way it came.

"There," Raph says. The image stops, and then suddenly jumps forward, bringing the sign into view. "You're at Pier 59."

"That's between 17th and 18th," Don says, as the camera jumps back again.

"Yeah, I know that," Raph says.

"Just saying," Don murmurs, and then he's moving again, heading towards the roads that cut off the waterfront from the rest of the city.

"Hey, guys," Mike says, materializing suddenly to lean on Leo's shoulder. "You playing a new video game? Lame graphics."

"It's Donnie," Leo says.

"Donnie made these lame graphics?" Mike reappraises the screen, then shakes his head. "Disappointing. His work is usually so much better."

"No, it's Donnie," Leo says again. "He's out there and he's trying to get home."

"Not following the plot," Mike replies candidly.

As Don approaches the roads - busy even at this hour - Raph explains about the mattress and the broken glasses. When Mike is done laughing, he spins Don's chair into position, sits down in it - his feet not quite reaching the floor, Don is so much taller than him - and cracks his knuckles. "Donnie, my bro," he says. "You hear me?"

"Hey, Mikey," Don says. He sounds tired.

"So I'm told we're basically playing a video game here," Mike says, seemingly completely at ease with carrying on a conversation through the computer. "Lucky you got a video game master for a little bro. We're gonna get you home and set the high score along the way."

"I don't think -" Leo starts, but Mike ignores him.

"First," Mike says, "Frogger totally sucks, so we're gonna go under this road."

"Which way?" Don asks.

"He's at 11th facing east," Raph says.

"Up bup bup." Mike holds up a hand in Raph's face. "Don't need a walkthrough, bro. Donnie, south."

Don obediently turns to his right, paralleling the road. Skillfully, Mike leads him to a pedestrian underpass.

"Might be people in there," Leo warns.

"There are people in there," Don confirms.

"Go in," Mike commands.

"Mikey -"

"Excuse me," Mike interrupts. "You had a turn, Leo. Now I'm playing."

Leo's temper rises in a flash. "Michelangelo, this is not a game! That's our brother's life! You can't -"

"Raph, would you remove this troll?" Mike says loudly, and the next thing Leo knows, Raph is herding him away from the desk. "These haters, man. So Donnie, is this a speedrun or what?"

And as Leo furiously tries to dodge around or batter through the brick wall that is his immediate younger brother, Mike guides Don into the underpass, even though they both know full well that there are humans in there.

The conversation reduces to terse commands as Don goes silent, and then there are the sounds of a swift and one-sided battle, and then Don is coming out the other side of the tunnel.

"I hate drug dealers," he's saying.

"How did you know they were drug dealers?" Leo demands, trying to stretch up over Raph's shoulder. "Those could have been innocent people."

"Innocent people, in a place like that in the middle of the night?" Raph says. "What kind of strategic genius are you?"

"They could have been homeless," Leo says, but no one is listening to him.

"So how was the scavenging?" Mike is saying, as Don crosses into Manhattan proper and looks for a fire escape to climb.

"It was good," Don says. "I got a load of -"

"Wait," Leo says, pitching his voice so the microphones - wherever exactly they are - will pick it up. "You still have a load? You're carrying a pack?"

"Of course," Don says.

"Why didn't you tell me?" Leo says, and Raph throws up his hands in the international sign for strategic genius!

"Thought it was self-evident," Don replies, and then it's clear that Leo is not needed or wanted in this conversation anymore.

He heads off to find Master Splinter. Their sensei hadn't emerged from his chambers during this whole debacle, but Leo is granted admission as soon as he knocks.

"Master," he says, kneeling automatically. "Donatello has left home. He broke his glasses and -"

"I am aware," Splinter says, without interrupting his calligraphy practice.

Leo slams on the mental brakes, but can't quite stop the next words from piling out. "- we're guiding him back. But -" And then he's able to switch to another track, one that writes a furrow across his brow. "How did you know?"

"Leonardo," Splinter says, with a warm smile, "I don't need a computer network to see what is happening with my sons. A father always knows."

Suddenly, Leo understands why Don never insists on Splinter wearing a headset. At least, sort of.

"But how?" he asks.

"Someday," Splinter says, "you will understand." He lays down his brush. "Let us go. I want to see Mikey playing this game."

When they get back to Don's nest of computers, Mike and Don are having a running debate about current events in the plot of their favorite comic book series, even as Mike guides Don across the rooftops of lower Manhattan.

"How are you doing that?" Leo asks.

"You really should spend more time gaming, Leo," Don answers. "It teaches you a lot about how to give commands to other people."

"Most impressive, Michelangelo," Splinter says, eliciting a "Hi, Sensei," from Don as he executes Mike's previous command. "You boys have done well, guiding your brother home."

"I'm not home yet," Don points out. "I'm still approximately 3.6 miles from the Lair."

"Indeed," Splinter says, and touches Mike's shoulder. "Might I take a turn?"

Mike cedes control, and Splinter immediately begins issuing commands for moves that are no more effective than those Mike had recommended - in Leo's opinion - but which are much more difficult to perform.

"I feel like I've just been hacked," Don pants, after he completes the sequence and pauses to rest.

"Did you think you would not get in trouble for this?" Splinter says, his tail curling and uncurling in that slow and dangerous way. "No student of mine loses a fight with a mattress and walks away unpunished. Have I not taught you better than that?"

"I know," Don says. "I should have been more careful about the -"

"You should have lied!" Splinter says over Don's apologies. "Had you said you had been incapacitated by a real enemy, we all would have been happy just to have you home. But how we shall ever get over this dishonor, I fear I do not know."

No one speaks. No one can tell how serious their father is.

"Anyway," Splinter says, "look over the edge here. Let us see if you can get underground."

The camera image leans out over the edge of the roof, revealing a couple of officers patrolling slowly on foot.

"Police," Splinter says, for Don's benefit. "Jump one more roof. You can outpace them easily."

Don calibrates his jump by Splinter's commands, flashes across the alley, skids down the far side of the building, and drops through the manhole just before the officers come around the corner.

"I can find my way from here," Don says, as he gains his bearings in the familiar tunnels.

"I am proud of you, my son," Splinter says, dropping the stream of commands and slipping into normal conversation. "You have used your strengths to overcome your weaknesses and come home safely."

"Not by myself," Don says heavily.

"I did not say by yourself," Splinter replies. "One of your strengths is your trust in your brothers. You called on them, and they were ready to help you. There is no shame in this."

"We didn't do it very well," says Leo. "We should have been able to help him more."

"Yes," Splinter agrees. "You must practice this. Donatello will break his glasses again. Or one of you may be temporarily blinded, and need similar assistance."

"But we won't be able to call home," Leo points out.

"You will if you keep your headsets on," Don says. "I called all three of you and only one of you answered. You other two - and you know who you are - my next move will be to implant the transceivers in your skulls. You've been warned."

"Geez, we get it," Raph mutters.

"Sorry, Donnie," Mike says.

Leo silently makes a resolution to stop throwing his headset on the floor. Then he spends the next ten minutes watching Don cover ground at a steady pace, navigating only by his mental map of the sewers. "I'm going out to meet him," he says, when Don is just a few turns from home. No one stops him as he heads out into the sewers.

("Don't you wish you could see?" Leo asked Don one evening, not long ago. Don was sitting with his glasses off and his eyes closed, repairing some small bit of tech, guided only by touch. Uncorrected, his vision was so poor that he found it disorienting, and said it was often easier to see nothing at all.

Don didn't answer for a long minute. "When I imagined being a human," he said slowly, "I imagined being a mostly-blind human. It's just how I am."

"But wouldn't you want to be able to see normally?" Leo pressed.

Don turned towards him, orienting to the sound of his voice, not needing to see his face. "Sometimes I wonder what it's like," he said. "I guess it's like a pair of glasses you never take off. That sounds exhausting."

Leo puzzled over this for a while, watching Don painstakingly feel his way through the repair job, while his glasses lay just within reach on the side table. "Seeing is tiring for you?" he asked finally.

"Mm," Don said, and then he hadn't wanted to talk about it anymore.)

Don comes jogging around the corner, then, his near-sightless gaze fixed straight ahead. He doesn't seem to realize there's anyone in his way until he barrels into Leo, sending them both to the ground. He attacks reflexively, and Leo defends himself reflexively, and then Don is grabbing at his arm, not grappling, but feeling his skin, identifying him.

"Leo?"

"Welcome back, Donnie."

"You could have warned me!" Don shouts into his headset, and Leo isn't sure whether he can hear Raph and Mike laughing, or whether he just knows it must be happening.

Don climbs to his feet and helps Leo up, and together they walk to their front door.

When they get inside Don doesn't think to turn off the camera or the feed, so as they approach the stack of monitors Leo sees Mike and Raph and Splinter standing in front of grayscale images of Mike and Raph and Splinter. He sees them twice for his brother who can't see them at all.

Where Leo sees in stereo, Don hears double. He pulls his headset down around his neck, resolving his family's voices into one.

"That was totally awesome," Mike says. "When can we do that again?"

"What'd you bring us?" Raph asks, relieving Don of his pack and rummaging through it as Don reaches after him impotently.

Splinter approaches Donatello with more gravity. "How broken are they?" he asks.

In response, Don pulls his glasses from a pouch of his belt. They are, as he said, shattered - the frames in three pieces and one of the lenses in too many to count.

"Can you repair them?" Splinter asks.

Don plucks one of the thick prisms from his palm, and holds it up in front of his eye. Leo wonders if he can see a little sliver of clarity through it. "Not this one," Don says. "I need a new piece of glass."

"We will find you one," Splinter says. "In the meantime, can you use the other?"

Don puts the shard down among its siblings, and fingers the intact lens. "It's all right," he says. In a smooth move, he pockets the broken pieces, takes off his goggles and passes them to Leo, and turns his mask sideways, covering his eyes. "I'm fine like this."

"Donatello -" Splinter begins.

"No, really." Don lifts his tech pack from his shoulder and sets it on the floor, sliding it under the desk. Straightening up without its bulk, he somehow looks even bigger than he really is, expanding into the space around him. He always did have enhanced senses, even without his infrared scanners and chemical analyzers. "We don't have to change who we are. The system works."

And with nothing but his ears and hands and memory, he finds his way to the kitchen and gets a glass of water.

The pronouncement, poetic as it is, turns out not to apply to this circumstance. Without his glasses, Don can't use most of his gadgets, and without that, they're all blind. Leo has some regrets about how dependent they've all become on Don's technological ESP, but the whole time the network is turned off, he feels himself on high alert, constantly straining to detect the first signs of danger.

"Is this how it is for you?" he asks Don, a few weeks later, worried that he's been unknowingly taking advantage of his brother for years.

"Oh, no," Don reassures him. "I'm never watching for danger. My sensors are doing that."

"But aren't you watching your sensors?" Leo asks.

"No," Don replies. "If they detect danger, they pop up a huge red warning sign right in front of my face. I can't miss it."

"Unless you're not wearing your glasses?" Leo asks wryly.

"Not even then," Don informs him. Then he sighs. "I'm weak, Leo. I want them back."

"What?" Leo asks.

"My glasses. And my sensors. All of it."

Leo puts a hand on Don's shoulder. Don's face is bare, his eyes tracking the blurry outlines of movement. "You're not weak, Don," he says. "You're not changing who you are. Being mostly blind is who you are, but so is being the Turtle with the tech pack."

Don frowns, not quite following this seemingly-contradictory logic.

"Your gadgets are part of you," Leo says. "Just as much as our weapons are. Just as much as Raph's loyalty and Mikey's sense of humor are."

"What's part of you?" Don asks.

Leo squeezes his shoulder. "You are."

A few weeks after that, they find the right type of glass, and make Don a new pair of lenses. Don rigs up a frame for them, and turns his network back on, and starts wearing his tech pack again.

And then he makes a gizmo that fits over his arm and functions as a tactile display for his onboard systems. He melds with his machines even more than before, effortlessly interfacing with them whether his glasses are on or off.

And then one day he comes up behind Leonardo, presses a smooth, cool device against his bicep, and pins it there with a leather strap that fits just right. As he pulls away, he presses the little button on the earpiece of the headset that Leo has hardly taken off since the day Donnie broke his glasses.

"Ask for the crime report," Don advises.

"Crime report," Leo commands.

"Downloaded," says a voice in his ear.

"Show me," Leo hazards.

Glowing characters burst across his vision, and in seconds, he knows where the bad guys are in his city.

Don looks surprised at the sudden appearance of the holographic display, and Leo realizes he's hardly ever seen this from the outside. He almost looks a little regretful, at having let someone else into this most intimate part of his world.

Leo reaches uncertainly for the device on his arm. "Do you…"

"No, no," Don says. "Listen, Leo… I don't want to turn you guys into me. But just try it out a little, okay? See if you like it."

Leo moves his hand sharply to the side, and the display obediently vanishes. Don looks hurt, taking the gesture as a sign that Leo hates the technology already.

"I don't want to turn you into me, either," Leo says. He's been noticing more and more lately how uncomfortable Don is looking at people when he talks to them, and he drops his gaze away, unsettling as it is for him. "Will you teach me how to send a text?"

He can feel his brother light up, as Donnie launches into an explanation of T-SMS.

Later, he painstakingly taps out a message to Donatello.

Thank you for the device.

Within seconds after he thinks the message has been sent, the device beeps, and a reply flashes up on the holographic display. It purports to be from Donatello, and it appears to consist entirely of punctuation marks. Leo can't make heads or tails of it.

Sometimes, that's how it is with his brothers. He's learning to accept it. Systems aren't static, Donnie always says, and sometimes, change is good.