Even extreme radiation trials.
To keep breathing, people had poured in more effort than anyone could imagine.
All those years of research had produced exactly one usable answer: Varanium weapons, capable of holding Gastrea off for a while without touching the root of anything.
Past that, the only other yield was the Suppressant, handed out once a Cursed Child had been identified. It slowed the climb of the Corrosion Rate for a time, carried brutal side effects, and damaged a child's body if used long enough. Nothing else. Not one thing.
Gojo showed no disappointment at any of it. If anything, he looked like a man turning something over.
He rubbed his chin. Behind the dark lenses, blue eyes shifted, and Enju Aihara surfaced in his mind, along with the faces of the children in that sewer.
"Ms. Muroto, there's something I want to know."
He stopped walking and turned to face her, none of his usual carelessness left in his voice.
"What is it?"
She halted too, brows drawing together.
"You're thinking of trying something. With regeneration like yours, honestly, you could push a lot further than most researchers ever could." Her eyes brightened, expectation creeping in. "With you there, at least the children stay safe. Even if an experiment goes wrong, you could pull them back in time."
She hesitated.
"But could you actually stomach it? Some of that work isn't humane. Even if it's meant to save more of them..."
Her voice thinned out toward the end, and something in her expression pulled tight.
She knew exactly what those experiments involved. Those girls had suffered enough already, and the thought of adding to it sat badly in her.
"Who said anything about experimenting on the children?"
Gojo's head turned, bewilderment written across his face like she'd said something absurd.
"Wait, that's not what you meant? I thought that was where you were going with it."
She scratched at her head, caught out, color rising.
She'd overshot. With his temperament, he probably wasn't capable of putting children on a table.
"Experiments? Couldn't bring myself to do it."
He tugged at his sunglasses, a small smile pulling at his mouth.
"Somebody this good-looking doesn't do unethical things. Wouldn't want to waste the face."
"I feel like that was aimed at me."
Her eyebrows went up. Years spent married to a laboratory had given her a fine ear for that particular kind of jab.
"Don't misunderstand. Never said a word."
He shrugged, all innocence.
"Anyway."
The lightness dropped out of him and his gaze went distant.
"Ms. Muroto, suppose someone existed whose constitution gave them a Cursed Child's power with none of the cost."
"Could you study that person and find a way to change these girls?"
Her eyes flew open. She grabbed his arm.
"No side effects at all? You mean the Corrosion Rate doesn't rise? They never turn into a Gastrea?"
Her voice shook. This was the question she'd been chasing for over a decade.
"If someone like that existed, God, if only."
She let go of his arm and drew a long breath, working to steady herself, longing running underneath every word.
"It'd take time. Repeat trials, the gene sequence picked apart over and over, the physiology mapped out. But there'd be a direction. A road you could walk down someday."
"Instead of this. Nothing in our hands, nowhere to even start, watching those children walk into a wall one step at a time."
Her mouth twisted around the helplessness of it.
"It's fine. There'll be a way."
He said it quietly, and there was nothing perfunctory in it.
"Really?"
She looked up at him like someone gripping the last handhold on a cliff.
"There will be."
He nodded, certainty running through it, and behind the lenses those blue eyes held steady.
An idea had already taken shape in his head. Nothing solid enough to say out loud yet, so he kept it.
Betty glanced up at him and her lip curled slightly. He hadn't said anything, but she knew that look. He was cooking something strange again.
She'd had his measure for years. That particular expression always meant a scheme underneath it.
The walk out of the 39th Area took the better part of an hour before Tokyo proper opened up in front of them.
They crossed broken walls and gutted foundations, boots grinding over loose rubble, and the dust in the air thinned out by degrees until it gave way to cooking smells and exhaust.
All three of them slowed when the noise of the city hit.
Shops stood open along both sides of the street, staff calling out from doorways. Pedestrians hurried past, heads bent over phones, laughing with whoever walked beside them, stopping to pick over goods at a roadside stall.
It fell short of what peacetime had been. Gastrea warning notices still hung along the walls, patrolling officers passed at a clip now and then, and something faintly wound-up hung in the air. Even so, it beat the desolation behind them by a distance that didn't bear measuring, and it beat the lives those children were living by more.
Gojo stopped and looked back.
Behind him, the 39th Area stretched out gray and endless, a corner the world had set down and walked away from.
Ahead, the city roared. Lamps coming on. Voices everywhere.
Half ruin, half plenty, the two of them meeting along one line, and the joke of it landed somewhere unpleasant.
"What are you looking at?"
Betty tipped her head back, her small face giving away nothing.
She'd seen this gap in every world she'd passed through. The same unfairness, the same contrast. You went numb to it eventually.
"This boring world."
His voice came out soft, something rueful buried in it, his gaze gone somewhere far off.
"Every world's the same, isn't it?"
She said it flatly, dismissively, the coldness of someone who'd stopped expecting otherwise.
"Yeah. Every world's the same."
He didn't argue, only nodded.
Because whether it was Lugunica, or his own world, or Tokyo tonight, it never changed. Someone always lived on the edge of impossible. Someone always got played with by fate. Someone always fought their way through the dark.
All he could do was reach down and pull a few of them out.
The three of them wandered on.
Streetlamps flickered awake along the way, warm yellow pooling on the pavement, dragging their shadows out long and sliding them forward.
Walking in the open like this didn't bother Sumire in the slightest.
For years her Gastrea Virus research had made her a target. Hunted by more factions than she could count, she'd stayed hidden, living in places the light never reached. With Gojo beside her, she could finally let her shoulders down and take in the ordinary noise of people going about their evening.
Somewhere along the way her lab surfaced in her mind, and impatience showed on her face.
"Speaking of which, when does my laboratory get sorted out? I've got mountains of experimental data to organize and plenty of work waiting."
She'd lost enough time already. All she wanted was to get back to the bench, where the numbers might still hold a thread of hope about the Gastrea Virus.
"Easy. One phone call."
He waved it off like it barely registered.
For him, it was simple. If he asked, the Seitenshi would move every piece she had. A laboratory hardly rated as an ask.
By then they'd reached the edge of a shopping street.
It ran louder than anything they'd passed, storefronts packed shoulder to shoulder, vendors calling, prices being haggled down, laughter cutting through it, chaotic and full of life.
Gojo reached for his phone to call the Seitenshi about the lab. His fingers had barely touched it when a bright voice cut through the noise.
"Thank you."
"Thank you."
Young, sincere, ringing out over the crowd.
He followed the sound and found a girl sitting on the ground, a cloth tied over her face.
Seven, maybe eight. Thin enough that a strong gust looked like it might take her. Her clothes had been washed pale and patched in a dozen places, and her hair hung dry and yellow, sticking to her cheeks in tangles.
The thick black cloth over her eyes said plainly that she couldn't see. A chipped ceramic bowl sat in front of her with a scatter of coins in the bottom. Begging.
A handful of thugs stood over her, grinning down with amusement in their eyes.
The one in front had bleached his hair a blinding yellow and wore a loud open-collared shirt that showed off the tattoo crawling up his neck. A cigarette hung off his lip. He squatted on the pavement, malice sitting plain on his face.
The others matched him. Green hair on one, studs in another's ears, a phone spinning in someone's hand, snickers breaking out every so often.
One of them crouched down, careful and quiet, lifted a coin from the bowl, and tapped it lightly against the ceramic rim.
A clear little chime carried through all that noise, straight to the girl's ear.
She had only sound to go by. Every time she heard it, she bowed deeply, thanking whoever had given, her face open and glad.
"Thank you."
Small voice, honest, without a shred of doubt in it, as though somebody had been kind.
People walked past. A few frowned without breaking stride. Others dropped their eyes and pretended not to notice. Two or three lifted phones and took pictures from a safe distance. Nobody stepped in. Nobody wanted the trouble.
Those thugs looked exactly like what they were, arrogance coming off them in waves, and no one was going to take that on for the sake of a blind girl begging on the street.
They were biting back laughter now, faces bright with it, and inside a few seconds every coin was gone from the bowl.
They lifted them one by one, exchanging looks, eyebrows going up, enjoying themselves like this was a fine game.
And the girl saw none of it. She kept smiling, turning toward each sound, thanking the empty air.
"Thank you. Thank you." Each bow went lower than the last, that small body folding forward, and it hurt to watch.
Coins in hand, they traded a last smug glance and turned to leave.
Before he went, one of them worked the pull tab off a soda can and flicked it hard into her bowl.
A dull clunk.
"Thank you."
Nothing registered. She bent again, bowing deep, the smile on her face as clean as it had been the first time.
Gojo's steps slowed.
Something cold moved behind the blue of his eyes.
"Ugh. Nasty little punks."
Sumire's face darkened, disgust plain, her stare fixed on the group.
She'd spent her life in laboratories, but she had lines she wouldn't cross, and tormenting a blind girl fell well below every one of them.
She turned to Gojo, expectant, and fairly certain of what came next.