This story changes the events of the movie a little. In this AU:

The fire was an accident and has no plot significance.

Callaghan isn't evil.

Tadashi doesn't die (I could never do that to him haha don't worry)

Hiro starts at SFIT normally (well, a few weeks late since he and Tadashi end up in hospital and need to recover)

I don't own Big Hero 6 or any of these characters.

~princess

The flames flicked spitefully in the dark night. People ran screaming from the building, almost falling over in their haste to get away. Tadashi and Hiro, however, were running in the opposite direction to everyone else; Tadashi's caring instincts had taken over immediately and he was anxious to make sure that everyone safely left the building. His little brother Hiro was right behind him. If Tadashi was going to be in danger, so was he.

Tadashi paused for a moment to look distraught at the fire, the he frowned and carried on running. Hiro gulped and sprinted after him, staying close to his side.

"Are you okay?" cried Tadashi to a passing woman.

"Yeah I'm okay, but Professor Callaghan's still in there!" she shrieked, pointing back at the building. Without a second thought, Tadashi raced over to the steps.

"TADASHI!" yelled Hiro, seeing Callaghan running out from behind the building. He had probably escaped through a window or another door. "DON'T GO IN THERE! CALLAGHAN'S HERE!"

Tadashi's head whipped around and his face was relieved when he saw Callaghan a short distance away. The professor moved towards him anxiously. "Tadashi, get away from there!" called the man. Hiro was crying now, but the boy didn't even notice.

Tadashi began charging towards them, but the building suddenly violently exploded and the blast sent them all flying backwards. Tadashi tried to grab Hiro as he fell, to ensure that his brother landed on top of him, but it was no use. The blast was too strong.

Later, at the hospital:

Hiro's eyes slowly opened. He was in a white room that smelt strange, and a bandage was wrapped around his head.

A woman in a blue uniform was in a corner of the room, busily writing something. When she glanced up and noticed that Hiro was awake, she rushed out of the room.

Confused, Hiro sighed and closed his eyes again. He was interrupted by a man's voice.

"Did you say he's awake?"

Hiro's eyes snapped open to see a doctor standing worriedly by his bedside.

"Yes, I'm awake," he said, accompanied by a coughing fit. He was surprised by how much of a struggle it was to say that, and how raspy his voice sounded.

The doctor noted something down. "Suffering from the smoke, I see. You also have a head injury."

"Do I?" Hiro couldn't feel anything at all except the bandage on his head.

"Yes. We've given you some strong painkillers but you'll be feeling strange for a while. No long lasting damage, though."

Hiro's stomach twisted as Tadashi slipped into his mind. "Where's my brother?" he asked.

"Is his name Tadashi Hamada?"

"Yes…" Hiro's hopes rose; if they knew who Tadashi was, he must have been brought here too. Surely his injuries were no worse than Hiro's.

"He's in a different department. He's broken his leg and fractured his ribs. He's also suffering from the smoke. No head injuries, though. You'll both be fine."

"Can I see him?"

"If you can walk, yes."

Hiro pushed himself into a sitting position and swung his legs over the side of the bed. He slowly got his feet, swaying slightly but determined to see his brother.

The nurse showed him into Tadashi's room. The broad shouldered young man was sitting up in bed, and smiled at Hiro.

"Hey, bonehead! Glad to see you're awake!"

Hiro beamed and scrambled onto the bed, sitting cross legged besides Tadashi, careful not to touch the man's legs.

"Are you okay?" asked Tadashi in concern.

"I'm fine," said Hiro contentedly.

"You don't look fine with that massive great bandage on your head," said Tadashi, gently flicking Hiro's nose.

"It doesn't hurt," reassured Hiro.

"Wait till the painkillers wear off."

"Tadashi!" whined Hiro. "I'm fine. Are you?"

"Aside from my leg being broken and my ribs hurting slightly, I'm great. Hey bonehead, your voice doesn't sound too good…"

"Oh, yeah," said Hiro hoarsely. "It's just the smoke."

Tadashi took a glass of water from his bedside table and handed it to his little brother. "Drink up, bro."

Hiro rolled his eyes but took the glass and sipped from it. "When do we get to go home?"

"You'll probably get to go home soon. I'll be in here a while longer, just because of my leg."

Hiro wasn't happy about that. "I'll be lonely," he protested.

Tadashi snorted. "You'll have Aunt Cass and Mochi. I'll be stuck in here. I won't even have my favourite bonehead," he teased, ruffling Hiro's hair.

"How can I be your favourite? You don't call anyone else that," countered Hiro.

"Doesn't matter," said Tadashi, grinning at him. "You're still my favourite."

Hiro's cheeks turned a pretty shade of pink. Tadashi burst out laughing.