Notes: The last thing I need is another project eating at my brain, but here we go. I'm going to try updating this on Fridays.

This is the first in what is starting to look like a series. This one's going to be a bit short, because I'm not going to write the movie scenes that didn't really change. Assume if I didn't go into detail that it's the same. As it is, I'm borrowing heavily from the movie for this one so if you recognize anything, like certain dialogue, it's either directly from the movie or a paraphrase and I don't own it.

Happy reading. :)

A Few Seconds Difference

The San Fransokyo Institute of Technology's Exposition Hall was on fire. Hiro's thoughts raced once he became aware of that fact even as he ran towards the doors. Amidst worry for the people still inside, although it had been emptying rapidly when they'd left not ten minutes earlier, there was a sense of loss for his microbots, which were no doubt going up in flames, and an angry thought at whoever's project had been so ill-designed as to cause the fire to begin with.

Tadashi was running as well. Hiro wasn't slow, but Tadashi had longer legs, so he'd already paused by the woman who'd stopped to cough once outside by the time Hiro caught up.

"Is everyone out?" Tadashi was asking.

"Professor Callaghan's still inside," the woman replied. Oh no. Hiro recognized the expression on his stupid older brother's face. When, sure enough, Tadashi turned to enter the building, Hiro grabbed him and dug in his heels.

"Tadashi! Are you crazy?! You don't run into the burning building!"

"Someone needs to help," Tadashi argued and thank god he was taking the time to argue, because he could out-muscle Hiro's skinny little boy arms. Hiro was so looking forward to growing out of this skinny little body.

"Yeah, the firefighters! Come on, Tadashi! They're trained for this! You're not!"

"But they're not here, and I am," Tadashi replied. And damn him for being so resolute because Hiro faltered in the face of it. His grip on Tadashi loosened. He'd forever hate himself for that, because Tadashi took the loosening of his grip as permission, shrugged free, and ran for the doors.

"Tadashi!" Hiro shouted, fear lighting his nerves as he saw his brother silhouetted by the fire burning inside the building. Then the explosion hit. There was a frantic nanosecond as Hiro realized he couldn't see Tadashi before the shock wave sent him flying off his feet and tumbling through the air, only to hit the ground several feet back.

"TADASHI!" Hiro shrieked as soon as he found his breath again. Oh god, no. A moan from behind startled Hiro because he'd thought everyone else had been smart enough to leave the area. A quick look over his shoulder was followed by him scrambling, not quite on his knees but not actually upright, over to the all too familiar body even as it moaned again.

"Oh god, please. Please, Tadashi. Please. I'm sorry I didn't stop you. Just don't die on me. Please. Tadashi-"

"You can see him now," the nurse stated softly. Aunt Cass made an undefinable noise even as she grasped Hiro's arm. She would've dragged him to the room the nurse was leading them to if Hiro wasn't half dragging her at the same time. Then they were there and Hiro felt like he couldn't breathe.

"Hey. There you are," Tadashi stated sleepily from the bed. He was heavily bandaged, had an IV in his right arm and his left was covered from shoulder to wrist in a huge cast that was not only bent at a ninety degree angle at the elbow, but also wired to keep Tadashi from moving it around while in bed.

"You okay?" Tadashi asked, obviously focusing on Hiro's bandages.

"A little banged up. Nothing like you, though. You were closer to the explosion and it threw you farther. They say you completely shattered your arm. They had to reconstruct it and pin and plaster it in place," Hiro said a little shakily.

"You're going to be setting off all kinds of metal detectors now," Aunt Cass said with a small smile as she tried to find the bright side of the situation. She was amazing like that, Hiro knew. Unless she was angry. Then her rants were epic, if random. Hiro loved hearing them on the occasions they weren't aimed at him. She was a great mom, even if she'd never claimed the title.

"Well, that'll be interesting," Tadashi said, favoring their aunt with a smile.

"Ma'am? I have some forms I need you to fill out," a different nurse told Aunt Cass, and who the hell dragged family away when they finally got to visit? Couldn't they have had her fill the forms out earlier while they were stuck in the waiting room while Tadashi was undergoing surgery?

"Alright. Lead the way. Stay here, boys. I'll be back."

"Okay, Aunt Cass. And don't worry about shorty here; I'll keep an eye on him," Tadashi replied with a smile.

How could he smile like that, Hiro wondered, when he'd come so close to dying? Hiro's fists clenched, remembering the feel of Tadashi slipping out of his grip.

"Hey, why so glum?"

Startled, Hiro took a deep breath and let his fists unclench. And Hiro knew he probably shouldn't say what had just been on his mind, but it was what was really bothering him and Tadashi would ferret it out eventually anyway, and Hiro would feel guilty for making him do so while Tadashi was stuck in a hospital bed. So he told the truth.

"I... I couldn't stop you and now look at you! You're in the hospital and you won't be able to use that arm for weeks, if not months!" Hiro said, angry at himself for his inability to stop Tadashi - for the way his grip had loosened for that single moment - and even more so for the tears he could feel stinging his eyes.

"Whoa! Hey, no! Me being in the hospital is not your fault, Hiro!"

"But if I'd managed to stop you completely, you wouldn't be hurt!" Hiro argued back.

"And if you hadn't stopped me at all, I'd be dead," Tadashi replied bluntly.

"Don't say that!" Hiro wailed.

"It's true, though," Tadashi continued calmly. "It doesn't take a trained firefighter to realize that there's no way I could have gotten to Professor Callaghan in time. If I'd gone in like I'd wanted, I'd just be another name on the list of causalities. Me being alive is because of you, Hiro. Me being in the hospital is me paying the price for my stubbornness."

"Ahem." Both boys turned to see Aunt Cass standing in the doorway holding a clipboard filled with paper.

"If you two are quite done trying to claim the blame," Aunt Cass interjected, "The nurse told me Tadashi can probably come home the day after tomorrow. They want to keep you for a bit because you just got out of surgery. Afterwards, you'll have to come back for check ups and probably physical therapy after the cast is off."

"Really? Can't I have Baymax do that? I'm pretty certain he's fully qualified."

"You are not using your injury to test your prototype robotic nurse," Aunt Cass stated firmly.

"Yes, Aunt Cass," Tadashi replied glumly.

The day Tadashi was allowed to come home, Aunt Cass threw a little party and even allowed Tadashi to invite his - and increasingly, Hiro's - friends. Tadashi, his cast in a supportive sling, was sat at the head of the table so no one could accidentally bump his injuries, which included badly bruised legs in addition to his broken arm. Hiro was sat to his right and everyone else had left an empty space to his left for Aunt Cass as they gathered happily at the table.

"Wait until you try my wings. They'll melt your lips off," Aunt Cass was bragging as she shook the wings in a bowl in order to coat them with her special sauce.

"Yes! I can't wait!" Fred crowed. "Wouldn't melting be an awesome superpower?"

"Only if you could make yourself solid again," Gogo pointed out.

"Ah, good point. Hey, Honey, can you make me do that?"

"And keep you alive? No," Honey responded with a rather dismayed tone.

"Oh. Wasabi?"

"Don't even think about it," Wasabi replied even as he arranged carrot and celery sticks in precise patterns on his plate.

"Tadashi?"

"Sorry, Fred. Robotics doesn't tend towards melting people. And even then, I don't know how much I'm going to be able to do in the lab until this heals," Tadashi replied with a smile even as he gestured at his arm.

"Right. Sorry, dude. Little dude? You got any ideas?"

"Huh?" Hiro startled out of staring at Tadashi. Tadashi frowned slightly at the sight.

"He wants to know if you can give him the superpower to melt and reform," Gogo replied with a smack of her gum.

"Oh. No. Sorry, Fred."

"No problem, little dude. Now how about some wings! If they're as good as Ms. C claims, maybe they'll give me superpowers!"

For the rest of the meal, Tadashi was aware of Hiro staring every time Tadashi struggled with something, and he struggled with a lot of things. Who knew he'd used his non-dominant arm so much? As it was, he wasn't certain whether or not to be embarrassed when Aunt Cass had to wipe the sauce off his chin for him because his good hand was just as messy. And wings weren't the easiest things to eat one-handed. At least it was finger food and Tadashi didn't have to figure out how to cut things with only one hand in front of his friends.

The movie they decided to watch distracted everyone for a time, but the staring returned once the others were gone and Aunt Cass had sent them up to their room for the night. It was probably Tadashi struggling to change his clothes that had prompted the new bout.

"Hey," Tadashi called to Hiro, hoping to break the stare. "A little hand here?"

"Oh," Hiro said as he startled before hopping off his bed. "Right."

It was much easier with an extra pair of hands helping him maneuver. And Tadashi refused to feel embarrassed because it was Hiro helping him and Tadashi still remembered helping to change Hiro's diapers.

"Hey. What's wrong?" Tadashi asked once they were bedded down and Hiro had started staring again.

"Huh? Oh, nothing. Just thinking."

Tadashi thought about following up and asking what Hiro was thinking about, but he had a memory, one he wasn't even sure was a memory because of how dazed he'd been after the explosion and how fast he'd been put under by the EMTs who'd arrived soon after. In the memory, he was in pain and staring up at Hiro, who was bruised and bleeding and crying as he begged Tadashi to be alright. It shook him to the core, that memory and, if it was true, well... Tadashi was willing to give Hiro some space if that's what he really wanted.

The next few days, it was like Hiro was avoiding Tadashi. Tadashi wasn't sure how to feel. It meant Hiro wasn't staring at him any more, but it was because Hiro wasn't there to stare. It kind of hurt, having his little brother avoid him. As it was, Tadashi had started regularly checking on the GPS he'd stuck in Hiro's sneakers just to make sure Hiro wasn't running off bot fighting. But he was still hanging around the house, in the garage or their room, mostly.

When Hiro started spending most of his free time in the garage, Tadashi thought about speaking up but, between helping Aunt Cass, doctor's visits, and making sure Baymax's chip was up-to-date, he never seemed to find the time. When it was less than a week before college classes were due to start back up and Hiro still hadn't registered for any classes, that's when Tadashi decided to get involved.

"Hey, I thought you were really excited about winning this," Tadashi stated as he strode boldly into the garage, holding the scholarship certificate Hiro had won.

"Tadashi? Hi!" Hiro chirped a little too cheerfully as he quickly tried to close the privacy screen he'd set up and hide what remained visible with his own body.

"Hi," Tadashi replied slowly, suspicious, before asking, "Classes start in less than a week. When were you planning on registering?" He wished he could properly fold his arms so he'd look a little more intimidating.

"What? Really? I didn't realize," Hiro said, sounding truly surprised. He then grabbed Tadashi's good arm and tried to lead him out of the garage. "We'll have to go and register right away! If you go get your moped, I'll just grab the envelope and we can go."

"You mean this envelope?" Tadashi asked as he broke free from Hiro's hold, waving the paper he was holding. "And I can't drive the moped with a broken arm. What are you doing in here, anyway?"

"Wait! Tadashi! It's not finished yet!" Hiro shouted, trying to prevent his older and larger brother from peeking behind the privacy screen. But Tadashi, even with a busted arm, was stronger than Hiro and easily managed to get past his brother.

"Is that... an exoskeleton?"

"Uh, yeah. I was trying to modify the extra neurotransmitter we made for the microbots so it would move the exoskeleton. Then, even if you couldn't move at all, it wouldn't matter because you could just think it and the exoskeleton would move for you. Except I keep running into some sort of weird interference and it's slowing me down."

"If... when you get this to work, Hiro, it's going to help a lot of people," Tadashi stated, feeling so very proud of his little brother.

"Even you?" Hiro asked hopefully. Ah. Suddenly the staring earlier made a lot more sense.

"Me? It's just a broken arm. I'm not that lame, Hiro."

"Oh, yes, you are. You're the lamest big brother ever," Hiro teased. And really, Tadashi knew he'd walked right into that one, but still...

"Come here, you little-"

"Ack! No! Leave the hair alone! Ah! Tadashi~i!"

A Few Months Later - San Fransokyo Docks

"Hello, Tadashi," Baymax greeted in his usual calm tone while Hiro, standing beside him, looked about ready to hyperventilate until Tadashi stepped out of the blinding headlights.

"You! What are you doing here?" Hiro demanded.

"What am I doing here? I saw my little brother sneaking out of the house with my robot dressed in armor and wondered what the heck they were up to. And since I can't fit you, me, and Baymax on my moped, I called the guys and asked for a ride," Tadashi replied, gesturing with his head back to where their friends were piling out of Wasabi's car. "Now, maybe you won't mind tell me why you are here?"

"Yeah, of course! On the way back, because we should leave," Hiro agreed far too readily as he grabbed Tadashi's good arm and tried to lead him back to the car. Except the others had gotten out of the car by now and joined them.

"There you are, little dude!"

"You worried us, Hiro," Honey Lemon scolded gently even as Wasabi nodded in agreement.

"Uh, we should leave."

"Why is Baymax wearing carbon fiber underwear?" Gogo asked as she popped a bubble of gum.

"No, we really need to leave," Hiro insisted.

"What's going on, Hiro?" Tadashi demanded, folding his arms, silently grateful that he could. The cast had come off eventually, even if physical therapy continued to be a pain. Then he paled as a freaking shipping container was hurled at them. Everyone scrambled to get out of the way except for Wasabi, who curled up and screamed like, well, like a girl, although Tadashi was never saying that around Gogo. Thankfully, Baymax caught the container and set it down right before a wave of microbots carried a creepy guy in a kabuki mask into view.

"Baymax-" Hiro started but Tadashi beat him.

"Car! Now!" he ordered even as he grabbed his stupid little brother and hauled his scrawny ass to the vehicle as fast as he could. He was in the middle of the back seat, Hiro on his lap and the belt buckle stretched around them both within seconds. Fred and Honey Lemon slid in on either side of them even as Hiro protested, "Oh, come on! Baymax can take this guy!"

Tadashi didn't bother dignifying that with a response because, while the microbots were all Hiro's idea, Tadashi had helped make and test them and thus had a pretty damn good idea of what they were capable of. And because they weren't his idea, he held them more in awe than Hiro did, which meant Tadashi had a much better idea of how dangerous they could be in the wrong hands. And scary mask guy? Definitely the wrong hands.

Sure enough, as soon as everyone was in the car and buckled, Baymax came flying through the air and landed heavily on the car's roof with a mildly uttered, "Oh no." Wasabi hit the gas soon after and then began the chase.

"We're being attacked by a supervillain, people! Isn't that cool? I mean, it's scary, of course, what with him trying to kill us, but cool!" Fred enthused, causing Honey, Hiro, and Tadashi to all give him looks. Gogo may have as well, but Tadashi had to look away from her to give Fred his look and Wasabi was too busy driving.

"Why would you say that? We don't know that he's trying to kill us," Honey argued for the sake of being fair. Then there was a screech of metal and everyone was tossed about a bit as Wasabi had to jerk the car about to avoid getting hit by the wreckage that was being thrown at them.

"He's trying to kill us!" Honey shrieked in alarm.

Then they were off the docks and on the streets and it looked like they might have a head start if Wasabi kept going which is, of course, when he stopped at a red light.

"What are you doing?!"

"It's red!"

"There are no red lights in a car chase!"

Tadashi, while he was normally a big fan of Wasabi's safe driving, was currently in Gogo's camp. There was a time for safe driving, and during a chase was not it, especially not when you were the ones being chased. Gogo thankfully took over soon after, although Tadashi ended up making a mental note to never, ever let her drive him or Hiro outside of a chase scene. As it was, he had to stop his stupid little brother from trying to undo the seat belt and climb into the front.

"Aw, come on, Tadashi! Wouldn't I be safer buckled into my own seat?"

Before Tadashi could even think of a reply, Baymax, up on the roof, stated, "It is a proven statistic that being buckled in the back seat of a moving vehicle is the safest position, especially for shorter individuals."

"You heard him," Tadashi stated with a slow grin.

Hiro shot a betrayed look at the dented car roof. The point became moot a few minutes later anyway as the car ended up in the bay.

"If I hadn't just survived a car chase with a supervillain, this would be the weirdest thing I've seen tonight. But I did, so it's not and that's just sad," Wasabi stated as everyone stared at Fred's room. Well, rooms, actually. Who knew Fred was rich? Not Hiro and obviously not anyone else judging by the reactions. Although, Hiro reasoned, he should've expected something like this the moment he'd learned the fanboy was loaded. The others seemed to realize that too, a little too quickly for Hiro's taste because he was now in the unenviable situation of having to explain.

"Alright, Hiro, what the heck is going on?" Tadashi demanded, folding his arms. Hiro hated when he did that - it was like his brother was trying to purposely look bigger - even if he was glad the injured arm was doing well enough to do it again.

"I found that microbot you got back from Krei moving in my jacket pocket and put it in a petri dish because I thought it was broken. Later, when I was messing with the neurotransmitter, I thought maybe whatever was causing the frequency disturbance might be what was making it act weird, so I moved it down to the garage. Then a few days ago I stubbed my toe and, well, Aunt Cass made you move Baymax to the garage when you're not home."

"You said 'ow', didn't you?" Tadashi stated with a look of understanding.

"Uh, yeah. Heh. Anyway, he insisted on scanning me and telling me I'm apparently suffering from puberty and mood swings," Hiro continued, rolling his eyes at this part, "and generally being a nuisance until he noticed the microbot. I told him it was broken and what would make me happy would be fixing it. He offered... I don't even really remember what he offered, beyond his help and I said 'yep' without even thinking about it and the next thing I know, he'd wandered off with the microbot!

"I knew you'd kill me if I didn't find him and bring him back, so I followed him but didn't manage to catch up until he'd stopped outside this old warehouse. I tried telling him again that the microbot was broken, but he insisted it wanted to go inside and when I tried turning away, I saw he was right. The microbot kept going in the same direction, towards the warehouse. So we sneaked in through a window. That's when I found out that guy in the mask stole my microbots and was making more. He's probably the one who set the fire."

The one who was responsible for Tadashi having been so badly hurt. Hiro clenched his fists at the thought but he took a deep breath and forced himself to relax and continue on.

"We got out of there once he started coming after us. I went straight to the police, but they didn't believe me! So I took matters into my own hands."

"Which included putting armor on a nursing bot?" Gogo asked, making her gum crack.

"I know karate," Baymax offered.

"I, uh, gave him a second chip. So he could fight."

"Hiro, why didn't you tell me?" Tadashi asked, looking disappointed.

Hiro hated having put that look on his brothers face, but the fire had made something clear he'd never really thought about before then. For the longest time, he'd viewed his big brother as something invincible. But the fire had brought home that Tadashi was human and fragile and all too easy to hurt. Too easy to kill. And Hiro had known, deep down, that what he was doing was dangerous and hadn't wanted to put Tadashi into that same danger. What if he got hurt again? But it didn't look like keeping him out of this was going to be something Hiro could do any longer.

"I... you were busy and I... I didn't want you to get hurt," he admitted, looking down at his feet as he scuffed a shoe against the carpet.

"Oh, Hiro," Honey Lemon whispered even as Tadashi took a deep breath before striding forward and pressing Hiro's head against his chest.

"Hear that? That's my heartbeat. And as long as my heart's beating, I'm going to be there for you, even if it means following you into something dangerous. Big brother's prerogative. Got it?"

Hiro bit his lip and blinked back the tears that threatened to form even as the sound of Tadashi's heart thundered in the ear that was pressed to his brother's chest.

"Y-yeah. I got it."

"Good. So what was this plan your big brain came up with?"

"Well, I was going to have Baymax fight his way to the guy and take off the mask. It has to be hiding the neurotransmitter, you know? Except Baymax doesn't seem able to fight without some direction, which means I might have to get closer."

"Closer?" Honey Lemon exclaimed even as Wasabi added, "Not alone, you're not."

"How else are we supposed to get the guy's mask off?" Hiro asked.

"There has to be another way. I mean, what was he even doing at the docks?" Tadashi insisted, pacing the room even as he rubbed his arms.

"Oh, yeah!" Hiro said, snapping his fingers before striding over to the table and snatching up a pencil and a piece of paper before sitting to try and draw that symbol he'd seen earlier. Baymax waddled after him.

"Your body temperature is still lower than ideal. Would you like me to warm you?"

"Yeah, sure," Hiro agreed absentmindedly. He paused in his drawing when Baymax leaned over and around him in a comfortably warm hug before shrugging and continuing on. He was vaguely aware of the others draping themselves against Baymax when he heard Fred murmur, "It's like spooning a warm marshmallow."

"What're you drawing, Hiro?" Honey Lemon asked. Hiro held up the paper so the others could have a better chance at seeing it from around Baymax's bulk.

"Any of you guys know what this means? It was on a container I saw the guy moving with the microbots."

After much shuffling around, the following chorus was all negative, making Hiro frown.

"Look, whatever's going on, we'll put a stop to this," Tadashi said as he took Hiro's shoulders in his hands. "Perhaps if we take this to the police-"

"And what?" Hiro interrupted. "They didn't believe me earlier and even if they do now, what're they going to be able to do against that guy? We'd be better off sending Baymax after him again."

"Yeah! We're with you, Hiro!" Fred stated with his usual enthusiasm.

And maybe it was the room or maybe he had been spending way too much time with Fred in general, but Hiro got an idea.

"You know, I think if we miniaturized your work at the lab and faced him together, we might be able to stop him," he insisted, looking at the poster in particular that had caught his attention. The others turned and looked at it as well.

"It will take more than just the police to stop that guy, what with those microbots," Gogo said.

"It will take precision, but we might be able to do it," Wasabi added.

"Well, working together is a good idea," Honey Lemon conceded.

"Of course it is! It's a great idea! What do you think, Tadashi?" Fred asked as they stared at the poster and considered becoming actual, honest-to-god superheroes.

"I think," Tadashi said, sounding resigned, "that we're about to prove that old adage that geniuses have no common sense." His friends and brother groaned at him.

"Aw, come on! Where's your sense of adventure?" Fred demanded to know.

"At the bottom of San Fransokyo Bay with Wasabi's car," Tadashi deadpanned. Then Hiro grabbed his arm and gave Tadashi his best puppy eyes.

"Please, onii~san!" Hiro wheedled. Tadashi ran his hand down his face as he sighed.

"Unbelievable. Alright, I'm in."