Levi pulled on his coat with a small grimace as the rough, restrictive material brushed against his skin. He glared down at his hands that still trembled slightly as he prepared himself for the walk back to the wolves' den.

Annoying.

Vestigial traces of his first heat still coursed through him, making him irritable and causing every minute sensation to register loudly. His clothes were like sandpaper against his skin. The cravat was a noose around his neck. After a quick glance at the series of leather straps, he had resigned himself to being slightly out of uniform. Despite this small allowance, Levi's skin crawled. The clothes were too tight, too rough, too hot. He couldn't move—couldn't breath. The need to squirm, to rip out of the uniform was ticking up his spine, growing more intense with each moment.

Levi clamped down on urge and forced his back straighter. His cadets would not see him in such a state. He would be the cool, composed Captain Levi they all expected from him.

The captain hadn't been aware he could even do such a thing as 'go into heat'. Levi had known since he was a child that he wasn't entirely human, he'd broken enough of his precious tea cups for that to be painfully obvious. He wasn't entirely shocked when he was told he was part wolf by the mutts they had salvaged from the blackmarket lab. The events that followed were what had left him shaken.

Hanji has said it was possibly the proximity of alpha pheromones that spurred his body into this hell. The female that they had found—Aadya—had herded him into the small cement cell she had claimed as her den when Hanji brought Levi. Aadya had crooned to him and offered him pillows and blankets that he could 'nest' with. The she-wolf had kept him company for the entirety of his heat, offering her warmth, guidance, and pheromones when he became agitated. Despite her claiming him with a mark she had placed along his neck the week after he had been made responsible for them, the alpha insisted that she would not bond him without full consent. Levi had been both astounded and grateful to find that no such bond had been created during those hours in her den.

Levi paused in front of the door to the holding cells that had been repurposed to serve as cages for the survey corps' new prize. His mouth curved with distaste as he fished out the keys, thumbing those used for the wolves' individual cells before claiming the key to the main holding area. The captain paused and listened to the sounds of a scuffle, the volume heightened due to his heat. His head tilted as he picked out Hanji's orders and the responding snarls of affirmation.

They had already started on the training.

It was rather pitiful how quickly the hybrids had agreed to be leashed hunting dogs for the scouts. After being raised in a lab as nothing more than live experiments, it wasn't all that surprising. But the predictability of their actions only made it all the more pathetic. They had no idea how to manifest their proud wolf heritage and assert their own will as anything more than wild beasts.

At least, that is what he had first thought. The more time Levi spent in the wolves' company, the more he doubted his own sanity. He was beginning to feel more in tune with the alpha and beta then he felt around his own troops. The captain's instinctual battle tactics that had always set him apart in the corp and left him labeled as a monster was mirrored in the wolf siblings. It was unsettling.

Levi turned the key and pushed his way into the underground stronghold. There was nothing but blank cement walls that greeted him as he made his way down the stairwell. The panting breaths and scuffs of training escalated with each step. Along the far wall there was a solitary strip of cells, their iron bars acting as the only relief from the monotonous gray of the walls. To the far right were the two cells that the siblings had claimed, the doors standing open. The wolves had stated that the air was fresher there, closer to the door—to the outside. Inside, the mattresses had been pulled from the bed frames and shredded to create more accommodating pallets.

Levi's gut swam as his eyes fell on the small cluster of blankets and pillows that he himself had arranged in the far right cell, right beside the mattress' torn remains. He wasn't sure if the feeling was unease or shame or disgust. Levi didn't suppose it really mattered.

As the captain made it to the bottom of the steps he turned, pressing his shoulders into the cement as he watched the siblings advance on Hanji. The human looked every bit as wild as the hybrids that circled her carefully, each rotation bringing them closer to her. The younger of the two wolf siblings, Eren, was in his wolf form. His shoulder was level with Hanji's shoulder as he crouched low, brilliant teal eyes focused on his prey, lips pulled back as each breath pushed out a new rumble. Aadya had adopted her hybrid form, her shoulder level with the top of the scientist's head, her gait liquid as she prolwed forward on giant wolf paws.

Levi scrutinized Aadya's appearance, his lips curling into a frown. When the scouts had stormed the facility, the experiment's conductors had been administering a new drug to the siblings. He could still recall the distinct timbre of their screams as the serum had torn through their veins. Their eyes had shone in the dark, bright with pain and panicked ferocity as they had attempted to fight off the scouts and the transformation that tore them apart.

The serum had been an attempt to further bridge the gap between the wolves that kept human civilization within walls and the people forced to live as nothing more that caged beasts—to create wolves that still thought enough like humans to fight for those without fangs and fur. The serum allowed the human/wolf hybrids to achieve the pure embodiment of this title. In their new form, the siblings' became bipedal with wolf legs that devolved into smooth skin above the knee. The fur that began at their paws trailed up their legs, down their spine to a full tail, and down their scalp to cover their shoulders and sweep down their biceps.

When Eren changed, he sported the same dark tanned skin as his sister. However, there was little other resemblance between the two. The wolf DNA resulted in severely contrasting phenotypes between the siblings. Eren's true form was that of a giant wolf, streaked chestnut fur and a monstrous maw hiding his human nature. However, one look at his reduced, brightly colored iris revealed how human the creature really was. In this case, the boy's eyes truly were the window to his soul.

Even when she was in her natural, human form, Aadya was very distinctly other . She moved with power, with stealth, and with the pride of an alpha. Her eyes were strongly angled, the whites swallowed in the deep amber of her iris. The hybrid's shortly cropped black hair would meld into speckled dark fur when she changed. Despite her inability to adopt a full wolf form like her brother's, she was undeniably wolf .

As the siblings closed in on Hanji, the woman grabbed a handful of fur and began to vault over Eren's back. The boy yelped in surprise but held his ground, human eyes locking with his sister's wolfish gaze. Aadya leapt forward, sharpened black talons digging into Hanji's jacket and ripping her from her perch. Hanji barked out a gleeful laugh as she wrenched her shoulders back, slipping out of the cloth's hold.

Aadya snarled in outrage as she gazed down at the jacket in her grasp.

Eren shot forward at a speed unbefitting of his size, snatching Hanji from the air as she fell, great paws clutching the woman close to his chest. Hanji wriggled in his grasp for a moment before admitting defeat.

"Alright, I'm caught. Well done, Eren."

Aadya waved the offending article indignantly, "I was not to harm you. This was the only way I could capture you without harming your fragile human body. How did I not win?"

Eren let out a string of chuffs and yips that only served to raise the fur along Aadya's shoulders and spine. The alpha's ears flattened into her hair as she snarled a curt response. Air huffed from the male in wolfish laughter and he wagged his shoulders at her.

Hanji interrupted their conversation, "Obviously, it was not the only way to capture me. And Eren was just seizing the opportunity you created."

"A beta should never steal an alpha's prey," Aadya insisted, tail held aloft in agitation.

"You still have a lot to learn about human strategy," Levi cut in. He pushed off from the wall to approach the group. Goosebumps rose along his skin at the rough caress of the cement as he did so. The uncontrollable physical response to the sensation only served to further sour his mood. "You are our trump cards against the wolves. If you fight like them, you won't be anything more than an annoying bug caught in their coat. You need to start fighting like Eren. Think like a human. Play dirty. It's the only way you will survive."

Eren's eyes brightened and his chest swelled with pride at Levi's underhanded praise. The giant wolf shifted from paw to paw in excitement before running into his cell. The air filled with cracks and pops as Eren shifted. The boy muffled a whimper as the change tore through his body, but despite the pain, there was a smile on his lips as he took on his humanoid form.

"Levi!" the boy's voice still held a light snarl from disuse as he called out, prancing toward the smaller man.

Levi glowered at him as a warning snarl filled the air, "That's Captain Levi, brat."

Eren deflated slightly as he took heed of his sister's warning before nodding to Levi, "Good morning, Captain Levi. How are you feeling?"

All eyes feel on him in anticipation for the answer, each for different reasons. Levi bristled, "None of your damn business."

Hanji let out a crow of interest, "It seems he's back to normal. That was a little under 36 hours, if I'm calculating correctly. Is that normally how long omegas are in heat?"

Eren shrugged, "Hell if I know. We didn't really have access to omegas in the facility, for obvious reasons."

"Watch your mouth, brat," Levi snapped, "Who the hell taught you that kind of language?"

Hanji raised an eyebrow at him, "He is still learning how to form the human language, Levi. If you don't want to hear him swear you shouldn't say those words around him. He is very impressionable."

Levi glowered.

In truth, he was glad to hear Eren speaking. For the first week, the beta had frequently resorted to scribbling words in the dirt or yipping to his sister in frustration when finding that he couldn't accurately form human speech, despite his affinity for it. There was something about the wolves' language that set Levi's teeth on edge and his blood aflame. At least when speaking to each other like this, he didn't have to endure that feeling.

Hanji shrugged and continued, "Either way, the fact remains that Eren won this match. Which means Aadya, you're with me. Since all four of us can't fight in here, we'll be going outside."

"What will you do if she runs?"

Aadya settled her gaze on Levi, her voice quietly melodic as she murmured, "Even if there was somewhere for me to run to, I would never leave my mate behind. Rest assured, my omega, I will not leave you."

Levi's body flushed with heat. If he'd had hackles, they would have been raised. He brusquely pushed past the alpha, absently rubbing a hand against where her mark throbbed above his clavicle. Damn heat.

"So that means I'm training with the brat today."

"Yes, it does." Hanji answered, her voice held a trace of deliberation as she looked between the fidgeting hybrid and captain.

I wasn't asking.

The unease held in the air for a moment before Aadya let out a quiet chuff to her brother and began to climb the stairs. Eren returned the noise before turning toward Levi. There was a dusting of color on the boy's cheeks that Levi couldn't help but fixate on. It was just the training. Hanji always managed to pull some exertion from the siblings during their training despite the difference in raw strength.

Levi turned away from Eren, shouldering his way out of his jacket and holding out a wrist to unbutton his sleeves. He dropped his jacket on a pile of blankets and pillows, freezing as he realized where he was. Levi ground his teeth at the nest and the jacket that now laid atop it. Despite the urge to wash away every trace of the last 36 hours, the captain couldn't determine a better place to keep his things. Reluctantly, he placed his cravat atop his jacket and went back out to face the beta.

Eren was where Levi had left him, an excited grin on his face—tail held high and ears pricked. Levi set about rolling his sleeves, sparing another glance at the boy as his claws clicked against the cement. His eyes flicked from the boy's parted lips, spread into a wide grin down, to his bare chest, then back to his sleeves.

"Aren't you going to put on a shirt?" Levi muttered as he began to roll his other sleeve.

Eren's smile waned as he looked down at himself and then back at Levi, "I only have the few shirts from Hanji, I don't want to get them damaged during training."

Levi grunted in response and began unbuttoning the collar of his shirt. Each button was like a fresh breeze washing over his face, a reprieve from the harsh scratching of the material. The captain forced himself to stop after the third button, despite how his nerves screamed to be rid of the thing.

Eren shifted nervously before offering quietly, "I did remember the pants this time."

Levi snorted, "Good to know you are actually learning something from Four-Eyes. Come at me."

Eren pouted, "I already knew humans wore clothes, I'm not an idiot. I'm not learning anything, I'm just trying to get used to a new habit."

"Come. At. Me." Levi enunciated with a bit more force than was necessary.

Teal eyes flashed and then he was upon him. Levi hit a run before the boy could reach him, gathering enough momentum to slide between the hybrid's legs as Eren shot forward. Eren spun, hands instinctively reaching for the floor, grasping for the study quadruped foundation. Levi turned, kicking off of the bars to one of the cells, landing a kick to the hip that left the beta sprawled on the ground.

"If you're going to look like a person you're gonna have to fight like one of us," Levi instructed as he spaced himself out again, waiting for the boy to stand, "Humans don't walk on all fours for a reason, brat."

Chided, Eren ducked his head before shaking off his blunder and squaring off with the captain. Levi felt satisfaction and a small hint of pride within him as he watched the boy widen his paws, mirroring Levi's own fighting stance. The beta's toes were spread, dark claws digging into the cement for a quick take off, his tail held steady for balance. Eren's eyes were focused now, his eyebrows drawn low as he watched for an opening, monitored the smaller man's movements.

Levi's mouth quirked. He knew that look. It would be difficult for him to land another solid blow on the boy. The omega's blood sang within him in anticipation and his hands trembled slightly. It was then that he should have noticed something was wrong—then that he should have called it off. Instead, he smirked at the beta with wild abandon.

Come at me.

As if hearing his silent command, Eren bounded forward, stooping only to grasp a wooden training sword Hanji had recently introduced to them.

"Yes!" Levi hissed, his smirk widening into a display of teeth. In the last sparring session before his heat had set in, he had urged the siblings to be aware of and utilize their surroundings. Use everything available to you to win. Use every dirty trick in the book—fight like a human . Levi felt true pride to see that the boy had taken the lesson to heart.

Levi grabbed hold of the sword as Eren swung, using the momentum to carry him over the brunet's shoulders. The captain lighted on his shoulders, wrapping his legs around Eren's neck and twisting. The boy fell to the ground and rolled, poised on the pads of his paws, a single hand on the ground, watching for his opponents next move. Levi sucked down a breath before continuing his assault—and then he froze.

There was a scent in the air that stopped Levi in his tracks. It was the smell of trees in the forest at night; of the quiet conversation swapped from branch to branch through flirting wisps of wind. But it was more than a scent. It was like the beginning of a song that he thought he was familiar with but couldn't quite grasp, the melody jumping just beyond his reach every time he began to recall. It was a rhythm without a melody, a melody without chords, a song without sound. Still, it wound through him and pulled him forward and sang and pulsed.

It was a song of endless forests and an open sky and a wide, pale moon. It rang with the chorus of howl's released with joyous abandon because they were free. It pulsed with quiet pants released into the night air and the warmth of a partner. A bond. There was the staccato of pups yipping and barking and howling and filling every void Levi had always had but never truly been aware of. A pack. The song was freedom and passion and love and warmth and not a song at all. But Levi didn't want it to ever stop, this song that wound through him and filled his every sense, these things that filled every void.

Eren was watching him, his pupils blown so wide the oceanic teal of his iris was nothing more than a quiet boundary into the black abyss. The beta's nostrils flared as he took in another quick breath before his eyes slid shut and he shuddered, the coarse fur along his shoulders raising slightly. When he blinked his eyes open again, they were dazed.

"I didn't think you'd respond," Eren murmured, raising from the crouch to tower above Levi, "And to respond so readily. . . I can hardly scent Aadya's claim on you. I had no idea if your scent glands would even be functional. You are. . . intoxicating."

Levi couldn't truly process what Eren was saying to him. The room was swaying around him, the air colored and pulsing with the song that was growing louder, punctuated by each tentative step of great, clawed paws. Eren hesitated, bouncing slightly before tucking his paws behind him and kneeling in front of Levi. The boy was slightly shorter like this, and the captain found himself entranced by tan skin, pink lips, and that thin line of blue green that was the same no matter what skin he wore.

Nostrils flared once more before Eren licked his lips and leaned in. Levi's breath stuttered as soft, moist skin brushed against his collarbone and a quick inhale left his neck cool. An uneven breath in brought the song to a roar, filling every thought and pushing every image away but one. A bond.

Levi whined slightly and the sound was so inhuman, so wolf , that it almost pulled him out of the trance. But then Eren's wrist smoothed down the column of his already slick throat and Levi was pulled into the beat, the dance, the song, the want.

"I've seen humans do this before," Eren breathed against the faltering omega's pulse, "I'd always wondered why. Wolves have no need for kissing, no means for it. But it always seemed to bring such joy and passion. I'd always wanted to try it. Always been jealous of my sister and her human lips. Would you let me try it, Levi?"

The melody was so loud it was thrumming against his skull, pushing his heart to match the rhythm. Something within him recoiled at what the boy was saying, but he still couldn't hear the words. Was the beta speaking the wolves language again? It was a quietly melodic and emotional language, full of quiet nuances and joys that he could never hope to understand despite the small part of wolf that danced in his veins. The older man wanted to hear more of it, it filled him with a sort of melancholy. The feeling of belonging to something without truly being a part of it.

Eren's brows furrowed and he cocked his head at Levi, his ears swiveling to drop into his hair, "Can I?"

Was it a sound or a smell or a color that filled the air between them, answering the boys plea with another, more carnal plea?

Eren smiled, his long canines leaving soft imprints along his lips. Tanned skin gave way to something darker and redder as blood filled the boy's cheeks. Claws grazed along Levi's jaw as Eren took his face in his hands. The beta shifted with brief uncertainty, sparing a glance at the door, before leaning forward and pressing his lips against Levi's.

It was nothing more than the soft press of lips and the quiet warmth of another body, and then Eren was pulling away. Levi's breath followed the boy.

"Well?" A rough voice splintered through the moment, drawing confused teal eyes back to his.

Eren's face was furrowed with a frown and he sighed heavily, "I don't understand why humans are so attached to this display of affection. It wasn't overly pleasurable."

The air was punctuated with another snarl that tore through the song, a baseline that hadn't been in mind when the song was created, but still allowed the music to flow.

"That's cause you're doing it wrong, brat."

The boy gasped as Levi launched into his chest, lips crushing together, teeth clicking. Clawed hands fluttered by the smaller male's sides, their dance accompanied by quiet sounds of shock, escaping from behind captured lips. Eren's wrecked whines tumbled into a purring snarl that buzzed against Levi's lips as strong hands tangled burnett tendrils, guiding the beta's head. The omega pushed closer, without a thought of how his weight atop the beta would affect him. Eren trembled under him, tanned skin going white hot under his hands.

Levi felt a thrill go through him as he pulled back for a moment to admire the effect of his ministrations to the boy. Eren followed after him as Levi pulled away, his golden skin flushed beautifully, pupils blown impossibly wide and dazed. His lips were only slightly swollen, but they were still parted in anticipation. Soft brown ears flopped so low against his head that they almost completely blended in with his tousled locks.

The strain was almost deafening now. Each inhale brought a new harmonizing line to life in the frenzy of voices and images that were playing though his mind. Every touch further stoked the heat that coiled low in his gut. The need to bond, bond, bond, reaffirming itself within Levi with each feverish beat of his heart.

Eren's chest rose and fell quickly as Levi shifted atop his abdomen, leaning forward to thoroughly destroy him.

When his lips brushed against his mouth and the beta gasped again, Levi licked into the warm opening. Eren went limp beneath him, completely still but for the tremors that shook his frame with each stroke of Levi's tongue. Levi whined into the beta's mouth. Why wasn't his mate returning his attention? Was he not doing it right?

Levi faltered.

His mate? Was that right?

It had to be, didn't it? Why else would he be pressed against the beta, chests rising and falling in a synchronized dance to match the beat of this chaotic melody without chords?

Claws pricked through his clothes and Levi let out a pained sound as the beta spun, crushing his smaller frame beneath him. Sharp canines pricked his bottom lip and the music screamed as hot blood trailed down the omega's chin.

Mark. Claim. Bond. Mate. Den.

Bond.

Bond.

Bond.

The beta rolled Levi once more, the captain's head cracking against the cement floor in the boy's haste. Levi almost couldn't feel the pain through the frayed refrain. Eren's breath was hot against the nape of Levi's neck, "Levi. . . can—can I bond with you? Will you let me be your mate?"

A roar split through the chamber, stamping down the song and making the beta go rigid.

"With my mate? My mate?" The words were hard to discern past the fury.

The beta's weight was thrown off of him and Levi was at once glad to be able to breathe and longing to have it back. Liquid amber eyes stared into his, pupils nothing more than a pinprick in the flame of her rage. The whites of the alpha's eyes flashed as she turned on her brother, letting out a stream of snarls and growling barks, her passion too great for the words of men.

Bones cracked as Eren's skin dissolved beneath mountains of fur until his true form stood proudly in front of Aadya, hackles raised, tail held high and lips pulled back to reveal jagged teeth as he bit back his response.

The alpha let loose another splitting bellow that human chords shouldn't have been able to produce and rose to meet her brother, fur emerging along her shoulders and legs, feet elongating until her weight was on her toes—her paws. Eren's snarls filled the room, in his wolfish form the male stood as tall as the corps' horses and weighed just under a ton. In comparison, Aadya seemed like no more than a tall, furry human. Despite that, Levi had no doubt who would win this fight.

Aadya snarled at Eren through her elongated canines before turning to settle her gaze on something past Levi.

"Get him out of here! " The alpha snapped, her words laced with enough power that the only thing Levi could hope to do is obey.

Gentle but insistent hands urged Levi to his feet and pulled him from the chamber as the scrape of claws against cement tore apart the remnants of the song.