A/N: Thank you to Lin, Ice, and obsessive-dumpling for reading all or sections of this fic. I really appreciated all the feedback. Extra special thanks to Joely for being my partner in this bang! Their work is phenomenal and you can find the first piece here.

This work is a part of the BakuDeku Big Bang 2022. There are 12 chapters and updates will be weekly.

Hush Little Baby, Don't You Cry

The first time Izuku had been in this alley, it was with his back pressed against the wall, threads of his costume catching against the rough concrete as Katsuki kissed him silly after a good fight. The dead end was off one of the main avenues in their assigned district—a two-lane road that was busiest during rush-hour, and somewhat quiet otherwise.

When they'd first diverted a rampaging villain down this street, they'd discovered the space Katsuki's explosions were allowed to take up, as well as the many lobbies, parking garages, and alleyways civilians could be herded to. It was now a mainstay in their strategy tool belt. Plus, it was just around the corner from their favorite date-night curry restaurant for when they finished a shift early.

This alley was where Izuku was hidden as he waited for Katsuki to draw their quarry close, looking forward to that curry as soon as they had the guy captured and cuffed.

Lying low was not, and had never been, Izuku's combat style of choice. Even less so as the rip, thunk, and crinkle of metal tore over the screams of civilians not yet evacuated—a car being thrown across the street and collapsing in on itself like one of the many crumpled metal cans here in the alley Izuku had concealed himself in. He jogged in place in the shadows, high noon on the dot not even providing enough sun to reach this sliver of street between skyscrapers, and listened closely. No yelps, no whimpers—he had a few moments more.

Fa Jin was nothing surer than calculated risk. The amount of strength Izuku needed to build up could not exceed the amount of time he had to spare. What he had to spare, at the moment, depended on his partner.

A new blast, the loudest yet, followed the sound of the thrown car rolling to a stop, the boom rattling Izuku's ears as it ricocheted off the hard walls. A loud "Die!" carried over both. Izuku risked a glance around the corner, hoping to finally catch a glimpse of the villain's weak spot. The smoke was too thick, though, clouding the narrow gap to the alley. They must have gotten close.

Katsuki had been on the scene five minutes already, caught between the rock that was this ram-headed villain's dense skull and the hard place of the armored vest he was wearing, protecting his more human middle. The quirk made the villain outsized, taller than either Izuku or Katsuki on two legs, and fast as hell when he ran on four. His horns were huge, sprouting from his forehead and curling around the sides of his head, protecting him as fully as a helmet. To compensate, his upper body was thick and stocky, in order to handle the weight of all that extra headgear. But without knowing if this was a transformation or mutant quirk, Izuku couldn't be sure if they were playing against stamina or time—he had to prepare for both. So with both legs humming with energy, he ran out of the alley and towards the smoke.

Smoke from Katsuki's explosions dissipated quickly—much lighter than the suffocating fog of One For All's Smokescreen. But as Izuku emerged on the street, it was still thick enough for Katsuki's appearance to be sudden, his body bisecting the cloud into two translucent plumes as he was thrown straight toward one of the concrete buildings that lined the streets. City blocks here were made strong—stable enough to withstand the region's earthquakes and most villain attacks. Concrete to break your back against.

Izuku sprang through the air, careful to hold onto his fastidiously stored Fa Jin in both legs as he intersected Katsuki's path. His thighs tensed and released, the snapping of a slipknot tied and pulled, propelling him up just in time for Katsuki's back to slam against Izuku's front, knocking half his air away as his own body armor smashed against his upper ribs.

They grunted as they fell to the ground, Katsuki grumbling, "Can't fire behind me if I can't see the goddamn extras on the ground," before taking off back towards the sound of destruction.

Another car had been upturned, caught by the villain's devilish horns and thrown overhead. There were still too many people around—Izuku had no choice but to leap in the direction of the car's trajectory, and kick it with all his strength, landing it hard against a concrete wall instead of in the throng of people still tearing through the road. It crumpled, frame bending like Katsuki's spine would have, glass on the far side shattering through the car's interior moments before it fell to the ground, the rest of the glass coming with it as hail in a Japanese spring. It came with screams, far too many as the villain hurled further into town.

Izuku ran forward, his iron boots crunching solidly through the glass shards and metal debris scattered over the potholed road. Katsuki was high above him, gaining momentum with alternating explosions before flipping to land in front of the villain and blow him back, straight towards Izuku.

"Get to safety!" Izuku yelled to the still far too many civilians stampeding around him. He only needed the few square meters required for close combat, but this was lunch hour, and people dressed in black still swarmed the sidewalk.

Katsuki's blast didn't do as much as Izuku would have hoped. The villain was too stocky and solid—perhaps his skin was thicker as well. Izuku did notice that a bit of steam seemed to escape the villain's horns. Either that had been a bit of wayward smoke, or his horns diverted some of the heat that should have been wearing down his body all this time.

Still, it blew the villain into Izuku's path, and as Katsuki came down, Izuku jumped up like they were on a seesaw and the villain was their fulcrum. Izuku angled himself diagonally, letting the power of Fa Jin reach its apogee in his legs as he aimed for the pulsing veins thickly framing the villain's neck.

His left leg hit home, crashing Izuku and the villain to the upturned street, shards of glass breaking against his costume. Before Izuku could right himself, a hand wrapped around his arm and whipped him around by it. The socket of his shoulder went loose like a doll's, as if connected to the arm by nothing but string. Not dislocated, but it would be in just a moment if he didn't act fast.

Izuku was flipped upside down, but he let the weight of his boots carry him down as his back curved in a great arch. The friction of his heavy shoes against the rough road slowed his momentum, keeping him from being thrown, though the angle of his arm had him moments away from the joint of his elbow or shoulder—or both—snapping.

With a great kick, Izuku threw both legs into the air, one after the other, and used the remaining stock of Fa Jin in his right leg to catch the villain right under the chin. He wasn't sure if the uncommon strength of this villain's skull extended to his mandible, but the bone was somewhat pliant under Izuku's foot, jutting to the right as his arm was freed from its sweaty hold. As weak a spot as any they'd found so far. Before he could make it far, though—swing himself over the villain's shoulder and reassess if he could stockpile more power—the villain's neck, red and already bruising from Izuku's first kick, jerked the other way. His giant, gnarled horns caught Izuku, lashing across both legs, and all Izuku could feel was the shattering of many pieces.

He fell to the ground, metal falling from the loose cuffs of his pant legs, digging in behind his knees as they bent to survive the fall. Mei's artificial Fa Jin device was now indistinguishable from the many remains of the few cars that had skidded past this same spot. All Izuku had now was a bit of defense in the Teflon against his chest, but nothing for offense but his raw strength, and his wit. It was all he'd had for five years.

"Fucking die, scum!"

And Katsuki, who was all firepower as his arms swung from position behind him, propelling him forward, and into the face of the villain, delivered an uppercut that opened into an explosion right under the chin. The weak spot sent the villain flying, horns steaming, as Izuku struggled to get up, trying not to let any of the many pieces of metal and glass that he'd landed in get any further under his skin.

Izuku pushed himself up with one gloved hand, reaching the other hand into the pouch on his hip containing quirk-canceling cuffs. Even underpowered against this villain, Katsuki could make this the end of the fight with just a couple more explosions—his quirk was overpowered on the warm spring day so it should even out. But all of a sudden, Izuku was stopped short by a touch, featherlight, on the back of his neck.

In a moment, he was taken back five years ago, to high school, the mall, a spot even more populated than this. Shigaraki's four-fingered hold around his neck. For a moment, Izuku felt it again, the dry skin, the cold hands despite the season and the open-air setting.

But there was no way. Shigaraki and All For One had been defeated five years ago, taking One For All with them. Izuku was here, and maybe he was quirkless again, but he was not useless.

Izuku whipped around, the grip on his neck loose enough that he could swivel out of it, and held his fists up at the ready. No sooner was he in position, ready to plant a right hook, than Katsuki blown into sight, a bare arm suddenly around the newcomer's neck.

"Kacchan!" Izuku protested. "The ram-headed—"

"Already cuffed 'im. Only have a minute—he's for sure a mutant, so those horns aren't going away." He returned his attention to the woman whose life he held in the crook of his arm. "Now what the fuck are you up to?"

Her thin ponytail that had gotten caught in the pinch of skin between Katsuki's bicep and forearm, yanking her head backwards, leaving her neck as exposed as Izuku's had felt in the moment she'd touched his. Her stance was pathetic as she clawed at Katsuki's arms, trying to free herself without an ounce of strategy. An obvious combat experience level of zero.

"Kacchan, wait!"

Katsuki's grip loosened just slightly, enough for the young woman to gasp, her voice mangled as she heaved, "Look behind you."

"Ain't falling for that," Katsuki said, but Izuku looked.

All he saw for a moment as he turned around was a man in a suit, like so many of the others who'd been forced to run from the scene. Only this man wasn't leaving—he was crouched, perhaps to tie his shoe, revealing a thinning spot of hair on the back of his head. Deku was about to turn back, thinking that he'd just been tricked by the oldest line in the book when an angry wail came from the ground beside him.

There on the sidewalk, blessedly past the worst of the debris, was a pink, nearly purple, wriggling, and very upset baby.

"Please, let me go!"

"Deku?"

"Let her go—get back," Izuku said, but his attention had shifted.

Sirens registered dimly in Izuku's mind, Katsuki's explosions too as he left the young woman to run for her life. But all those sounds were deadened against the wailing of the tiny thing naked on the ground. Its gristle-like umbilical cord was still attached, linked to something dark and gory beside it. But there were certainly no other signs of birth, much less anything resembling a mother. Just the businessman.

"Is…" that your baby , Izuku was about to ask, but of course it wasn't. This was a newborn. Clean and dry, but otherwise as fresh from the womb as if it had been delivered there at the crime scene. Instead, he said, "Excuse me, sir, I'll handle it."

The man hesitated before bumbling out an, "Are—Are you sure?"

"I'm sure," Izuku insisted, stepping forward. "Now please, get to safety."

Finally, the man backed away and Izuku moved swiftly. He tossed off one glove and tore off the other with his teeth as he crouched down, risking a bit of dirt and broken glass on his tongue. Better him than this little infant. His reflexive medical knowledge kicking in, Izuku ripped open an alcohol sanitizer pad and wiped his hands vigorously. Every moment longer it took for the alcohol to evaporate was a critical one for this baby. How long had it— he , at least supposedly, Izuku surmised from the visible genitalia—been here on the sidewalk?

Izuku pocketed the pad and reached for the baby, his hands suddenly shaky. He was trained in tying tourniquets, staunching wounds, CPR—even baby CPR. But Recovery Girl's medical classes had never taught him how to hold a baby. The little guy was wiggling, hopefully not moving too much against the coarse sidewalk or, god forbid, any shrapnel from the fight. Izuku moved down close.

"Don't worry," he said through a hero's smile. "I am here, little baby. I'll save you."

As Izuku reached down, delicately placing his fingertips right against the baby's sides, he was hesitant to touch any part of the sidewalk, even in order to wriggle his fingers a little further beneath the tiny body. He didn't want to touch any glass or contagions, or press even the tiniest pebble into the baby's tender body. His skin was so soft, the exact opposite of the weathered calluses and scars of Izuku's hands. Even the press of Izuku's fingers, gnarled and trained for violence, but trying to get a grip, might leave a bruise.

He finally had the baby scooped in his arms, not pressing him too close to his chest, untrusting of his costume after having been strewn through the street. The placenta, bloody and oddly warm, was on the baby's stomach.

"I will definitely save you," Izuku said again, his eyes darting from the baby's wriggling limbs, to his screwed shut eyes, to that flash of verdant hair. "I'll protect you, little baby."

It was then that he realized that the baby's hair was a dark, mossy green.

Izuku blinked. The baby's skin was flush with color, nothing resembling anything Izuku had ever seen on himself, outside of maybe when he'd been a kid tying string around his fingertips, watching them swell with blood, purple and pulsing. But that hair…

Izuku shook his head and stood, turning in a half circle to survey the scene; he was alone. The young woman was gone, as well as the baby's would-be benefactor. But Izuku was attuned to Katsuki's voice in the distance, and coming closer.

A rush of air blew Izuku's hair into his eyes, and he turned his shoulder to the wind, shielding the baby from it, nearly missing the ram-headed villain running past him. Adrenaline shot down the veins in Izuku's legs, which bent automatically at the knee, ready to run at full speed after the villain.

But he couldn't.

Katsuki was already on the villain's heels yet again, blasting up the avenue with explosions that made the baby in Izuku's arms wail. "What're you waiting for?" he shouted as he came in line with Izuku. There was a moment of silence between explosions and Katsuki landed on the ground. "Bastard ripped right through the goddamn cuffs—let's fucking…"

It was then that Katsuki noticed the screaming baby in Izuku's arms, and he took a step forward.

"Deku, what the—"

"Go!" Deku insisted, his voice quiet as he bounced the baby in his arms. "Win to save!"

Katsuki blinked once, but didn't hesitate a moment more. "Save to fucking win—fine!"

He sprinted a few steps down the block before he was airborne again. As the explosions grew quieter, Katsuki hopefully gaining on the villain, Izuku looked back down at the bundle he was holding. The wailing had stopped, the baby's gummy mouth closing to a pout as he wriggled, settling in Izuku's awkward hold.

Walking to the hospital would take fifteen minutes at best for Izuku these days. Fifteen minutes seemed far too long for something so tiny, so fragile.

But the police cars were still there. And they'd stay if Deku hurried. He clicked the button to unmute his earpiece. "Hold a car for Hero Deku, direct to hospital."

When Deku heard the copy, he began walking in the direction Katsuki had come from as fast as he could manage, allowing a little pulse into his arms as he carried his tender little bundle.

"Don't worry, little baby," Izuku murmured, unable to take his eyes off the tiny thing. "I gotcha. I know you don't know anything about heroes yet. But when you're with a hero, little baby, you're safe. I promise."

The squad car's door was open when Izuku made it to the scene where their villain was supposed to be carted up, ready to be transported for rehabilitation. The street glittered with glass, the sun, just after noon according to Izuku's watch, was overtop all the skyscrapers so that every little piece of debris caught its light, sending blinding refractions wherever Izuku looked. There were even more upturned cars—the villain's favorite move, it seemed—and light fixtures bent and twisted where they were meant to stand tall over the sidewalk. Izuku didn't know whether the villain hadn't been cuffed easily, or if this had been the result of his escape. Without him, now just the lone car remained and Izuku hurried towards it.

"The nearest hospital," Izuku directed again as he crawled in the barred back, minding every little jostle of the baby.

No further instruction was needed. The sirens went off, bleating just above their heads as Izuku shifted the baby to just one hand, buckling his seatbelt. Not to be outdone by the wailing squadcar, the baby screwed up his face, those chubby cheeks pushing wider than they already were, and started crying.

"Hush, baby, hush," Izuku cooed as the car began moving. Despite the crying and the sirens just overhead, the crunch of the tires treading over the bits of material that made city life—glass, metal, concrete—still resonated.

Izuku continued bouncing, and slowly, the baby's cries began to fade away again. Maybe he was getting used to the loud noise above them, or maybe something else had been troubling the tiny, little guy. Izuku brushed his hot tears away with his thumbs—with his fingers spread wide, he could reach nearly every edge of the baby. Perhaps comforted by the motion, the baby finally blinked his eyes open, squinting quite a bit between blinks, but gazing soulfully, if a bit cross-eyed, up at Izuku. Izuku's already constricted chest grew tighter, as if held in the tiniest grip of a baby's fist.

This little baby, with his shock of green hair piled thinly on his head, had startling eyes. They were red. Red from tears, red from screaming, red around the rim, and red encircling those dark, newly-seeing pupils. A red of fire, of rage, of love. A red Izuku had seen nearly every day in his twenty-one years of life.

They blinked closed again, but the color burned in Izuku's mind's eye.

Izuku swallowed, his throat dry, but he was unable to reach any of his pockets for the gels he kept on hand to drink. As the hospital rolled into view, he pushed all thoughts away and bounced the baby faster in his arms, murmuring almost unthinkingly:

"We'll save you, baby. We'll definitely save you."

The trip was only a few minutes long, the streets having been all but cleared due to the nearby villain threat, but Izuku spent all of it in a daze. He only became aware of their arrival when the police officer mentioned it with a tone that informed Izuku that he'd already wasted precious moments.

Izuku nearly stumbled getting himself out of the squad car. As he righted himself, he looked down frantically—the baby was still sleeping. He hoped, prayed that it was a good sign. That if something were wrong, the baby would let him know, right? Minding his movements, he threw a thank you over his shoulder and made it as quickly inside as he could.

"A baby!" he nearly shouted, peering wildly for the triage nurse. When his eyes landed on one, he hastened that way. "A-A newborn baby!"

A quirk baby is what he didn't say, what he didn't dare say until someone confirmed it. Perhaps there were tests for these sorts of things—Izuku didn't know the first thing about it. He always tried to gather more information about quirks, of course, including babies, but this , he…He was entirely out of his depth. He was running on instinct and had no clue what he was doing.

"Indeed there is!" the nurse said, holding out their arms in such a way that reminded Izuku that they knew what they were doing. They knew how to hold a baby. So he handed the little guy over, placenta and all—which made the nurse's eyes go wide when they noticed. Things went quickly from there.

"He was outside," Izuku informed firmly, focusing on what he knew as he followed the nurse, "on the ground of a crime scene. He was crying for a while, so his breathing should be fine. I didn't get a close look, but there don't appear to be lacerations. My costume isn't clean, though, but I tried not to touch him with anything but my hands. After sanitizing."

"You did well, hero," the nurse said as they entered an elevator. It moved quickly, compressing Izuku's joints for just a moment as they leapt up numerous stories. Then they were on the floor and Izuku was once again trailing behind. "You'll have a room—scrubs will be set out momentarily for you to change into. I recommend taking a shower, and use the soap generously. After some tests, we'll bring your son right back to you for skin to skin. Ah, this room should be good."

The nurse efficiently ushered Izuku into a hospital room, saying again that someone would be by with scrubs momentarily. Then she was gone, baby and all, and he was alone. He was still blinking down the hallway when a set of scrubs were pressed into his hands.

That turned him on autopilot. He found himself in the shower, with water that was tepid at best pouring over him. The bits of metal that had never fallen from his skin and out the looser pant bottoms of his newest costume tinkled to the tile floor, hurting like legos underfoot until the water swept them away. Thin lines screamed across his calves—scratches from the remnants of the faux-Fa Jin device, some deeper than others. They stung against the water and burned under the unscented soap that Izuku mindlessly lathered over his body. It bubbled up across his body hair before sliding easily down the drain. He was nearly clean when he remembered exactly what the nurse had said.

We'll bring your son right back to you.