Disclaimer: This is a fanfiction, I do not own Big Hero 6
Robert Callaghan staggered back as a wave of intense heat surged through the burning showcase building. The structure was quickly filling with smoke as people fled toward the doors. The aging professor lowered himself to his knees to escape the worst of the smoke and tried to crawl towards the entrance, hoping that the path was sill clear.
Professor Callaghan used a fallen display as protection as he surveyed his escape route. He saw that the front entrance was blocked by debris and flaming fragments. Coughing through the smoke, he turned around and crawled toward the emergency exits.
As he neared the back of the building, another surge of flames sent him scrambling back toward the presentation stand. Callaghan desperately looked for a way out but flames surrounded him on all sides. He needed a way to protect himself. Hiro's neurotransmitter! He saw it lying on the ground by the Microbots.
He rushed forward as the flames intensified. With all the high tech gear in the building, it was only a matter of time before something blew. He picked up the neurotransmitter and was about to place it on his head when he heard someone yelling.
"Professor!"
"What?" Professor Callaghan whispered. The voice was faint and unrecognizable. Could the firefighters have come that quickly? He doubted it. With all the chaos around him, he was probably hearing things. He looked for the cases of Hiro's project and was about to put the neurotransmitter on when the he heard the voice again, this time he recognized it.
"Professor Callaghan!" Tadashi called. "Where are you?"
He saw his best student struggling through the wreckage. Their eyes met for a brief second. Tadashi's eyes widened in dismay as realized that he could not help his professor. Nevertheless, he pressed on in a vain attempt to reach him.
The building was suddenly filled with light as an explosion consumed it. Professor Callaghan quickly turned away and shielded himself, placing the neurotransmitter on his head. He reached out with his thoughts and called the Microbots to him. He felt them respond and willed them into a protective dome around him.
Just in time. A split second after the tiny machines took the desired shape the flames reached him. Professor Callaghan could feel the intense heat from the fire seep through the protective barrier. Minutes passed and Callaghan began to feel faint.
Luckily, the heat began to dissipate and Callaghan slowly lowered the Microbots. He knew that the building was lost. Pillars were slowly cracking after sustaining damage from the explosion. Tadashi was nowhere to be found, most likely killed from the blast.
Bitterness engulfed his mind. Why would Tadashi make a mistake like that? Now he is gone without accomplishing his true potential in life. Just like Callaghan's daughter.
His daughter!
Callaghan looked at the Microbots under his control as he retreated towards a wall, watching as they responded to his thoughts. With a simple command, they broke a hole through the wall and lifted him out.
His thoughts strayed to Tadashi. He had really hoped that the young man would accomplish great things in his life. But the fire changed all that. Now all that was left was a prototype plush healthcare companion and a grieving family.
Callaghan shook his head. That was not important now. Tadashi made a mistake and it cost the student his life. Callaghan knew his own mistake was letting Krei get away with Abigail's death. Now he had the means of correcting it.
Professor Callaghan turned and disappeared into the shadows leaving his former life behind, his mind consumed with plans for justice. If he could reverse engineer the Microbots and improve on their design, Alistair Krei would soon know what it's like to lose everything.