He's alive.
The thought is terrifying to the professor. He isn't sure why, and he certainly doesn't have time to process it now. Tadashi Hamada is alive, with a bleeding burn on his forehead that looks like he's been struck and smoke seeping into his lungs with every shallow breath.
If he was dead he could leave him. But he isn't.
It takes a thought – less than a thought – for the microbots to swarm around them both. He can feel through them, like limbs he'd never known he had, and it's a sea of red-flagged temperature sensors. Tadashi's skin is cold in contrast. He can't tell how cold, all he has is comparisons.
The microbots stiffen and thicken in a bunker-like shell, a weave of hexagons like a beehive gone wrong. But there aren't enough. He can't block the air, can't keep the oxygen from rushing out. The microbots can keep the debris at bay, push away the flames.
But he still has to move, or suffocate.
The professor runs. The shell of microbots runs with him, dragging Tadashi along still caught in the weave. He has to leave him, the professor thinks dimly. If Tadashi lives, they'll have doubts about him as well. But...
If he was dead it would be simpler. If he was dead he could leave him. If he was dead no one would blame the professor. But...
There is just enough doubt for the microbots to keep their hold.
Down the emergency stairs, into the deep basement with the chemical storage and the thick-walled bunkers with faraday cages in the walls, through the emergency exit tunnel and into the maintenance area. They'd be watching the tunnels, they'd know he knew the escapes. But there is a thin place; he only knows because he'd been around when this place was built. The microbots are brilliant – self reinforcing hexagons and triangles form themselves into something like a drill, and the wall crumbles away before him. A service tunnel for the underground trains. He drags himself through the hole, and the microbots drag Tadashi after.
He keeps going, keeps running, until the smoke inhalation and his sedentary academic lifestyle catch up to him. The microbots collapse into a swirling ocean that breathes as he does. He slumps against a wall, and finally looks over to Tadashi.
He isn't breathing.
The microbots are still cooling, recovering from the fire. The professor can't feel through them like he had before. Tadashi still feels cold, cold, cold as ice, his skin a patchwork of burns and shining sweat. He reaches over with a trembling hand.
He can't find a pulse.
Tadashi is dead.
The professor releases a shaking breath. Dead. Dead. That... simplifies things. He can't pretend to be upset; he should be, and he will be later, but for now the adrenaline and sheer relief of having gotten away with it flood his brain and leave room for nothing else. Tadashi is dead. The professor had tried to save him. His conscience is as clean as it can be, cleaner than it would've been if he'd left him. He'd tried. And... It was Tadashi's mistake. Running in. Not the professor's.
The microbots pull back, letting Tadashi slump to the cold cement. The professor catches his breath, and stands.
He leaves Tadashi's body where it lay.
(Later he would regret it. Later he would mourn the boy. Later he would harden his heart and go through with his plan; Tadashi hadn't died for nothing.)
(Krei would have called it a setback, he thought dimly.)
(They never found the body.)
Days later, a family mourns over the graves of parents, and lays to rest Tadashi's memory in the form of a bronze-and-stone plaque. There was no body, so no coffin. No gravestone.
A brother, numbly, thinks Tadashi deserved better.
Weeks later, a white robot follows a microbot. The professor chases a boy away from a warehouse, and tries not to see Tadashi in him. The professor dismantles everything, and leaves through the service tunnels. The microbots surround him like a swarm, forming dark honeycomb around the edges of the tunnel. Their black tendrils chase off the homeless, the squatters, the druggies who come to the tunnels to live or hide or die.
He ignores them, swarms around them, passes them by. They have no one to tell. They might as well be faceless.
The microbots have to move one aside, a bony huddle of a man who shivers despite the warm, stale air, who refuses to uncurl even when the black tendrils prod at him. They swarm around him like a birds nest, and set him in a corner.
His skin is cold.
The boy is persistent. Tadashi's eyes shine in his face, and Tadashi's friends surround him, Tadashi's robot at his side. One takes his picture. The professor chases them until they driove into the bay.
He watches the van sink. The microbots can save them.
He doesn't bother.
(Krei would've called it a setback.)
(He knows better.)
He moves operations to the island and works. The portal has to be repaired. There aren't enough microbots yet. There is too much to do, not enough time. The opening of Krei's new headquarters is coming up fast.
Days pass. Weeks pass. He only goes to the mainland for supplies. The homeless watch him in an exhausted fear as he tears apart junkyards and travels through tunnels. He starts seeing Tadashi among the faceless. That is impossible. Tadashi is dead. Tadashi's brother is dead. Tadashi's friends are dead.
His students are dead. His daughter is dead. They have not died for nothing.
The professor works.
They find him. They weren't dead; they weren't even hiding. He just hadn't looked.
They looked.
They're huddled around the console where Krei had been, when it all went wrong, watching footage cued up by the professor himself. He hadn't wanted to watch her die again, but he needed the reminder. Needed that anger for fuel against Krei. And now they are watching her die. And they don't understand what they are seeing.
He throws a wall at them.
Tadashi's brother ran to Tadashi's robot, and the rest throw themselves at him in a disorganized fury. He could fight them, but they practically fight themselves. Fueled by grief unrefined by time, unpracticed nerves and powers they don't know how to use. Until Tadashi's brother digs the robot out, knocks him down, takes his mask. The microbots dissolve.
He isn't hurt from the fall. But he's missing limbs, eyes and minds and miles and miles of what might as well be his own skin. He hadn't expected the sudden separation to hurt. But oh, it does.
He doesn't hear the boy talking until he calls him Krei.
"I'm not Krei."
And it hurts, again, more than when Tadashi actually died. There is no adrenaline this time to protect him from the boy in front of him, hurt and angry and shocked and disappointed, with a face like the world's fallen away.
And then. The truth.
"That was his mistake!"
It's true, it's true, it's the shield the professor's used to protect himself from his guilt, but that doesn't make it kind. He recognizes his own blazing grief in the boy, as he runs and dodges and grabs the mask, avoiding the thing that is no longer Tadashi's robot.
He gets away.
The professor sticks to the tunnels. He can't be seen, can't be outed this close. He chases the faceless out of one of their havens after one reminds him of Tadashi; Tadashi's eyes, Tadashi's hands, Tadashi's burns wrapped up in someone else. His student is dead but he did not die for nothing. Abigail did not die for nothing. Krei would call them setbacks, but they aren't. Krei did this, this is Krei's fault, all of it, all of it. It's his mantra, his strength, his spine. He knows he's slipping from the truth, from reality, from sanity, but he is so close now. So close.
The microbots, his own limbs, are his bed, and he sleeps.
It's the end of things. Krei is in his grip, tense and fragile and colder than Tadashi. Abigail was not a setback, none of them were, and now that Callaghan's lost everything Krei will too. The portal starts up with a hum that sets his bones on edge; it's too much like it was. But that's what makes it perfect.
Then they show up. The robot is Tadashi's again, and the brother talks to him with Tadashi's words and Tadashi's eyes and only now does the boy understand what happened to Abigail.
But Abigail is gone. And they did not die for nothing.
He fights.
They're easy to trap. Still disorganized, unpracticed, scared. He is more than them, more than all of them, a creature of one man and a hundred million microbots, both singular and legion.
But then, Tadashi's words crackle through six radio headsets, and it changes.
New angle. New plan. They escape upwards and outwards and downwards, and he's bleeding. It's a gradual thing; he's so huge that it's hard to keep track of himself with his mind so clouded by rage, and the square so clouded by cold chemical fog. Microbots vanish one by one, and his limbs are shrinking. A thousand here, ten thousand there, one hundred thousand, one million. He knows they're going. But he has so many. If he can just get rid of Tadashi's brother, Tadashi's damn ghost, surely he can't...
Run out.
He runs out.
And Tadashi's brother quotes Tadashi's robot, and the mask crumbles to pieces. And his limbs are torn away from him again.
And he falls.
Abigail is alive. Tadashi's brother saved her. Hiro saved her. Tadashi's robot is gone, and Hiro mourns it like he must have mourned his brother. Callaghan watches his daughter taken away in an ambulance. He won't be with her when she wakes up. He'll be in prison.
He wonders what they'll tell her.
He watches the city from the back of the police car. Tadashi's friends are gone. Tadashi's brother is gone.
Tadashi's face watches him from the faceless crowd.
Tadashi is dead.
And Callaghan will never escape him.
(Abigail is dead. Abigail lives.)
(Tadashi is dead.)
(They never found the body.)