Burning Promise

The air in the underground compound was wrong. Too still. Too cold. That metallic tang of antiseptic, mixed with the sour smell of fear—like it had soaked into the concrete walls and was breathing out at them. Izuku had pictured this infiltration a hundred different ways. Tight corridors, sure. Armed guards, probably. A firefight, maybe. But not this silence. Not the way the fluorescent lights buzzed, casting everything in that sterile blue-gray that made shadows look deeper than they should be.

They had the layout memorized. The Shie Hassaikai's base was a maze of tunnels and chambers buried under the city like a tumor. Eri was somewhere in the central lab—that's what Aizawa-sensei's intel said. Simple mission: get in, get the girl, get out. No pointless fights. No heroics.

That plan lasted exactly forty-three minutes.

The trap was clean and brutal. A pressure plate in a service corridor, and then steel doors slamming shut behind them, sealing off the exit. Then the gas—a fine mist that smelled faintly like autumn leaves, laced with quirk-suppressant. Izuku's arms turned to lead. He watched his fingers tremble as One For All flickered out, leaving him weak and ordinary.

Bakugo roared, sparks fizzling from his palms into nothing. "What the hell is this?!"

Aizawa was already on the ground, his capture weapon limp, eyes unfocused. He managed one word before his head lolled back: "Overhaul."

Then the black-clad men swarmed them, and everything went dark.

---

Consciousness came back in pieces. First sound: a slow drip of water somewhere, the distant hum of machinery. Then feeling: cold concrete against his cheek, his shoulders aching from being bound behind his back with thick cuffs. Izuku blinked, vision swimming, and found himself staring at pale gray stone. Quirk-canceling walls. He'd studied enough to recognize that faint shimmer.

He tried to move. His limbs were sluggish, muscles burning. The suppressant was still in him, leaving him weak and useless.

"Oi. You awake, Deku?" Bakugo's voice was gravelly, strained. He sat a few feet away, wrists bound, that signature scowl on his face despite the bruises along his jaw.

"Yeah." Izuku croaked. He forced himself upright, head pounding. Across the small cell, Aizawa lay motionless, black hair splayed on the floor. "Sensei?"

A groan. "Still breathing."

Relief hit Izuku, but the reality of their situation dampened it fast. The cell was tiny—maybe six feet square. No windows. One heavy steel door. No furniture, no amenities. Just them, the cold, and the silence pressing in.

Days blurred together. The only markers of time were meals—bland rice and vegetables slid through a slot in the door twice a day by guards who never spoke, never looked at them. No questions, no answers.

Izuku tried to map the compound by sound. Footsteps in the corridor—sometimes heavy and regular, sometimes quick and furtive. A distant clang of metal. Once, a child's laugh that made his heart clench with hope and dread.

And then, on the third day—or maybe the fourth, he'd lost count—the door opened fully.

Guards entered first, four of them, faces hidden behind white porcelain masks. They flanked the doorway, rigid and alert. Behind them, a figure stepped into the dim light.

Izuku's breath caught.

Shoto Todoroki looked nothing like the boy from the Sports Festival. The one with fire in his left hand and ice in his right, eyes burning with defiance. This Shoto was thinner, paler. His heterochromatic hair was dull and matted. He wore a white patient's gown under a heavy coat, his wrists and ankles bound with thick, glowing cuffs—quirk-canceling restraints. A small patch on the inside of his elbow, the skin around it red and irritated. Anti-quirk injection. Constant suppressants dripping into his bloodstream.

But it was his eyes that hit Izuku the hardest. The left one, turquoise—cold, distant, empty. The right one, gray—flat and resigned. He moved with a kind of regal grace, back straight, steps measured, but there was a sadness in his shoulders that spoke of a weight too heavy for any boy to bear.

"New prisoners," Shoto said, voice flat, almost bored. He carried a tray in his bound hands, balancing it with practiced ease. "I'll take over meal duty for the day."

The guards exchanged glances, but didn't argue. One grunted and stepped back, letting Shoto kneel in front of the slot. He slid the tray inside—rice, vegetables, a small cup of water—and then, with a deftness that shouldn't have been possible with shackled wrists, he slipped a folded piece of paper into Aizawa's palm as he passed him the cup.

No one noticed.

"Eat," Shoto said, his gaze flicking to each of them. "You'll need your strength."

He left without another word, the guards trailing. The door slammed shut, the lock clicking with a finality that made Izuku's stomach twist.

Aizawa unfolded the paper with trembling fingers. The message was short, written in careful, looping hand:

Don't give Eri back.

---

Over the next few days, they watched.

The guards had installed a small observation window in the door—probably to check on them, but it also gave them a narrow view of the corridor. Not much, just a stretch of white wall and the occasional passing shadow. But sometimes the shadows stopped.

Shoto would appear with Eri clinging to his hand. The little girl was pale, white hair falling in tangled waves, her horn covered by a small cap. She looked fragile, like a bird with a broken wing. But when she looked up at Shoto, her eyes held a flicker of warmth.

"I don't like the doctors," she whispered one day, her voice carrying through the thin metal door.

Shoto knelt, bringing himself to her level. He carefully brushed a strand of hair from her face. "I know, little one. But I'll be here. I'll always be here."

"Promise?"

"I promise."

He straightened, and the guards ushered them away. But Izuku saw the way Shoto's hand lingered on Eri's shoulder, the way his shoulders sagged as soon as she wasn't looking. He saw the exhaustion in the dark circles under his eyes, the tremor in his fingers as he adjusted his cuffs.

"He's a prisoner too," Aizawa said quietly, gaze fixed on the door. "But he's also their weapon. Overhaul is keeping him docile with the suppressants, using him as a deterrent. A show of force. If anyone tries to attack the compound, Todoroki is the first line of defense."

"That's sick," Bakugo muttered. He'd been pacing for hours, frustration a palpable force. "He's one of us. He's a hero student. How the hell did they get him?"

"He was on a solo reconnaissance mission two months ago," Aizawa said. "He went dark. The Commission assumed he was dead. We never found a body."

Izuku's throat tightened. He thought of the note. Don't give Eri back. Shoto had risked everything to give them that message, to warn them. Even now, beaten and drugged and bound, he was still trying to protect her.

"We have to save him too," Izuku said.

Bakugo snorted. "We can't even save ourselves, Deku. We're stuck in a box with no quirks and no way out."

"Then we find a way out."

Aizawa said nothing, but his eyes—those tired, calculating eyes—held a flicker of something new. Determination. Maybe even hope.

---

On the third night since Shoto's visit, the door opened again.

No guards this time.

Shoto stood in the doorway, a ring of keys dangling from his fingers. Still in the shackles, still wearing that irritant patch, but his movements were quick, purposeful. He crossed the cell in three strides and unlocked Bakugo's cuffs first, then Aizawa's, then Izuku's.

"We have maybe ten minutes before they realize I'm gone," he said, voice low and urgent. "I've disabled the cameras in this corridor and the one leading to the lab. Follow me, stay silent, and do exactly what I say."

"Why are you helping us?" Bakugo demanded, rubbing his wrists. "You're one of them."

Shoto's eyes flickered—pain, maybe, or anger—but his face stayed impassive. "Because I'm not one of them. And because Eri deserves to be free."

He turned and slipped out the door, and they followed.

The compound was a maze of identical corridors and featureless doors. Shoto moved through them like a ghost, bare feet silent on the cold floor. He avoided main passages, ducking through service tunnels and maintenance shafts, his knowledge of the layout absolute.

At one point, they heard voices ahead—guards on patrol. Shoto pressed them against a wall, his hand hovering over Izuku's chest, a silent command to stay still. The voices passed, laughing about something. Shoto let out a breath he'd been holding.

"This way."

They reached the lab through a steel door marked with a biohazard symbol. Inside, bright and sterile, filled with monitors and tanks of swirling liquid. And there, in the center, lay Eri, curled up on a cot, her eyes wide and frightened.

"Shoto!" She scrambled off the bed, small arms wrapping around his waist. He knelt, holding her close, his shackled arms forming a protective cage around her.

"I've got you, little one," he murmured. "We're getting you out of here."

"Don't leave me."

"Never."

He lifted her into his arms, her legs dangling, face buried in his shoulder. She was so light, so fragile. Izuku's heart ached.

The exit was close—they could smell fresh air, feel a faint whisper of breeze from a ventilation shaft. But as they rounded a corner, alarms blared overhead. Red lights flooded the corridor.

"They know," Aizawa said, voice grim.

Heavy footsteps pounded toward them. Overhaul's men—dozens of them—materialized from the shadows, quirks already flaring. A wall of bodies blocked the path to freedom.

Shoto set Eri down slowly. He turned to Aizawa, face calm, almost serene.

"Take her. Run. I'll hold them off."

"No." Izuku stepped forward. "We're not leaving you. We came to save you too."

Shoto looked at him then, really looked at him. His mismatched eyes held a depth of emotion Izuku had never seen—gratitude, regret, and something that looked almost like pride.

"You can't save me, Midoriya," he said softly. "Not today. But you can save her."

He knelt beside Eri, and she clung to his hand, tears streaming down her cheeks. "Shoto, please don't go."

He smiled. A small, sad smile that didn't reach his eyes. But it was real.

"I will find you one day," he whispered, brushing her tears away with his thumb. "But until then, smile for me. Can you do that?"

She nodded, hiccupping, and tried to shape her lips into a smile. It was wavering, fragile, but it was there.

Shoto pressed a kiss to her forehead, then untangled her arms from his neck. He handed her to Aizawa, whose expression was carved from stone.

"Go."

Aizawa didn't argue. He turned and ran, Eri clutched to his chest, her small hand reaching back toward Shoto.

Bakugo grabbed Izuku's arm. "Move, nerd."

But Izuku looked back over his shoulder. He saw Shoto turn to face the oncoming horde. Saw him raise his hands, the shackles glowing, and then—a miracle. A flicker of flame on his left side, a bloom of frost on his right. The suppressants were still there, still draining him, but somewhere deep inside, Shoto had found a reserve of strength.

He shattered the shackles with a burst of fire and ice.

And then he charged.

---

The sound of the ice wall freezing shut was like a thunderclap. It sealed the corridor behind them, a barrier of solid crystal ten feet thick, glittering faintly in the dim light. On the other side, they heard the rumble of explosions, the shriek of ice, the roar of fire.

And then, silence.

Aizawa didn't stop running. He carried Eri through the tunnels, through the ventilation shaft, up into the cold night air. Bakugo and Izuku followed, legs burning, lungs screaming.

They burst out of a manhole cover on a side street, and the world exploded into noise. Pro Heroes swarmed around them—Mirko, Edgeshot, Gang Orca. Behind them, familiar faces from Class 1-A. Uraraka gasped. Iida shouted. Momo rushed forward with a blanket.

Eri was taken from Aizawa's arms, wrapped in warmth, and the little girl finally broke. She sobbed into Uraraka's chest, small body shaking.

"Shoto," she whispered. "Shoto…"

Aizawa stood at the edge of the manhole, staring down into the darkness. His hands were shaking. His eyes were red.

"We're going back for him," he said, voice harsh, cracking. "I don't care what it takes. We're going back."

Bakugo stood beside him, fists clenched, jaw tight. His voice was barely a whisper. "He bought us time. He fought like a damned hero."

Izuku sank to his knees, head in his hands. The image of Shoto's smile—that small, sad smile—was burned into his mind. He had been broken, drugged, beaten. And still, he had given everything.

"He's not dead," Izuku said, lifting his head. No doubt in his voice. "I know he's not. He promised Eri he'd find her. He doesn't break his promises."

The wind carried the faint sound of sirens from the compound, the distant echo of battle. Somewhere in the darkness, Shoto Todoroki had fallen.

But the heroes who escaped carried his fire with them.

Eri, wrapped in a blanket, face tear-streaked, looked up at the stars. She remembered his smile. She remembered his voice.

"I will find you one day."

She believed him.

And so, the hunt began.