Marcus shivered as he swam, the water growing colder with each stroke. Yet it wasn't the icy temperature that unsettled him—it was the sight of Lilith, glued to Caspian's side like she belonged there.

She was beautiful, alluring in a way Marcus couldn't ignore. Worse, she had everything Marcus didn't. The thought gnawed at him, filling his chest with a quiet, aching insecurity.

"Marcus?" a small voice broke through his thoughts.

He blinked, looking at Cassio, who hovered in front of him. The tiny fae's glow was warm, his wide eyes filled with understanding.

"Hey, Cassio," Marcus said, forcing a smile.

"Marcus is sad. Why?" the fae asked, tilting his head with innocent curiosity.

A soft sigh left Marcus's lips. "It's nothing," he replied, though his voice carried the weight of his feelings. "Just... a few insecurities."

Cassio's grin was mischievous as he floated closer, gently tapping Marcus's cheek. "Maybe Marcus can make himself look pretty?"

A blush crept up Marcus's neck, the suggestion catching him off guard. The thought of dressing up for Caspian made his heart flutter—a mix of embarrassment and something he didn't quite understand. He'd heard of such things in human relationships, where one partner adorned themselves in a way that pleased the other. The idea wasn't unwelcome, though it felt foreign in the world of the merfolk.

Before Marcus could dwell on it further, Caspian's voice called out, pulling his attention. "Marcus!"

He turned, just as Caspian broke away from Lilith and swam toward him, his strong hand reaching out to grasp Marcus's wrist. The touch was firm but gentle, grounding Marcus in the moment.

"I want you to see this," Caspian said, his black eyes glinting with excitement.

Heart fluttering, Marcus allowed himself to be pulled forward, Caspian's fingers lacing with his. Together, they swam past Lilith, leaving her behind as Caspian guided Marcus onward.

Ahead, a massive black castle loomed, its jagged stone walls rising from the ocean floor like the teeth of a great beast. Surrounding the structure, glowing lights pulsed softly within the thick ice that encased the kingdom, casting an ethereal glow over the entire scene. The icy barrier shimmered like a second shield, impenetrable and mysterious.

Marcus stared in awe, his breath catching in his throat. Words failed him as he took in the dark, haunting beauty of the Onyx Kingdom.

"My god," he whispered, the words slipping out unbidden.

Caspian's gaze flicked to him, his black eyes softening. "Do you like it?" he asked, his voice quiet and uncertain, as though Marcus's opinion mattered more than anything.

Marcus turned to him, his silver eyes glistening. "I love it."

Caspian leaned in, his lips brushing lightly against Marcus's in a fleeting, tender kiss. The touch was brief but electric, leaving Marcus's skin tingling. "Welcome to my home," Caspian murmured, his voice a low, intimate rumble.

Fingers still intertwined, they swam toward the towering black gates that marked the entrance to the kingdom. The massive doors were flanked by stoic guards, their dark armor adorned with intricate tattoos that stretched across their collarbones, visible through the gaps in their armor. As Caspian and Marcus approached, the guards raised their fists to their chests in salute, bowing slightly as the gates groaned open.

The moment Marcus passed through the threshold, something changed.

A sharp, overwhelming force hit him, knocking the breath from his lungs. His body convulsed as an invisible weight crashed down on him, cold and oppressive, seeping into his very core. He gasped, clutching his chest as an alien presence surged through him, twisting and merging with his own essence.

It wasn't just pain—it was something more. Something alive.

The sensation was indescribable, like being submerged in an ancient, unknowable power. He could feel it moving inside him, coiling around his soul, its presence vast and consuming. For a brief moment, Marcus's vision blurred, the world around him fading into a void of shadows and whispers. It was quick, a few seconds of pain before he felt normal again.

Confusion clouded his mind, searching for a realistic answer but none came up.

*****

Morgan had seen it.

In that fleeting moment, as Marcus crossed the threshold of the Onyx Kingdom's gates, he had witnessed the transformation—the brief but undeniable change. Marcus's silver eyes, so full of emotion and curiosity, had turned completely black. Not just the irises, but the whites as well, swallowed entirely by darkness.

It had been quick, almost imperceptible, but Morgan's sharp gaze missed nothing. The shift was unnatural, unsettling, yet deeply familiar. The presence of the Onyx God had touched Marcus, leaving its mark in a way that could not be undone.

A low chuckle escaped Morgan's lips, the sound soft but laced with something enigmatic. His green eyes glimmered with unspoken thoughts as he watched Marcus, who was now obliviously holding Caspian's hand, his face still pale from the experience.

"Things are turning for the better," Morgan murmured to himself, his voice barely audible, yet carrying a weight of certainty.

As the group swam deeper into the kingdom, Morgan lingered at the back, his mind racing with possibilities. Whatever the Onyx God had seen in Marcus, whatever purpose it intended for him, it would shift the tides in ways none of them could yet comprehend.

And Morgan was eager to see how it would all unfold.

****

Marcus's lips parted in awe as they approached a towering palace crafted from the blackest stone he had ever seen. The massive structure loomed above them, but beneath its formidable exterior, vibrant lights shimmered like trapped starlight, casting an ethereal glow over the surrounding waters.

"This is the Onyx Palace," Morgan murmured beside him, his green eyes alight with excitement.

Marcus chuckled, glancing over at Caspian. "So, Caspian knows the king here too?"

A deep, resonant rumble of laughter came from Caspian. "I am the king," he said, his voice calm but brimming with quiet authority.

Marcus barely had time to process the revelation before the sound of trumpets echoed through the water, their notes sharp and regal. Merpeople began to flood the area, their movements fluid and synchronized. Their hair shimmered in every color imaginable, but their tails were all the same midnight black, glinting faintly in the palace's radiant light.

Hands waved eagerly toward Caspian, who returned the gestures with a serene nod. His presence was magnetic, commanding without effort, and Marcus couldn't help but feel a pang of wonder—and something more profound—at seeing Caspian like this.

As they swam closer to the castle, the grand black doors swung open to reveal a cavernous hall. Guards stood at rigid attention, forming two perfect lines leading to a formidable throne carved from the same black stone as the palace. Beside it, a smaller throne sat slightly lower, its design no less intricate but exuding an understated menace.

Marcus glanced around, feeling dwarfed by the scale of the palace. He wasn't used to grandeur like this, and yet there was something unnervingly familiar about the place, as though he'd been here before in a dream.

"Welcome to my home," Caspian murmured softly, his breath brushing Marcus's ear. The intimacy of the moment made Marcus's heart race, his silver eyes flicking toward Caspian's dark, unreadable ones.

Before Marcus could respond, a merman with a strange tattoo on his forehead swam forward, bowing low. "Your Royal Majesty," he said, his voice reverent. His gaze flicked to Marcus, lingering for a moment on the dark tattoos swirling around his arms and fingers before returning to Caspian. "The Council has been awaiting your arrival. There are matters of the kingdom that require your attention."

Caspian inclined his head, his demeanor shifting seamlessly into that of a ruler. "Of course. Prepare my robes," he commanded, his voice steady but firm. He gestured toward Marcus and the others. "Prepare rooms for my guests. Ensure they have everything they need."

Marcus watched the interaction, his gaze following the subtle movements of Caspian's hand, the authority in his voice. It was a side of Caspian he hadn't yet seen, and it sent a shiver down his spine. This was not just the man he'd come to care for—this was a king.

Dark orbs met Marcus's silver eyes, the intensity of Caspian's gaze holding him in place. "Rooms are being prepared for you," Caspian said, his tone softening. "Food will be brought shortly. Rest, Marcus."

But Marcus couldn't ignore the weight in his chest. He glanced down at his fingers, his eyes tracing the dark tattoos that curled around them like living shadows. When he spoke, his voice was quiet but steady. "Why didn't you tell me?"

For a moment, something flickered across Caspian's features—an expression Marcus recognized all too well. It was the same look he'd seen in his own reflection on those long, lonely days at school, when teasing and isolation had worn him down to raw vulnerability. Guilt.

"I'll explain everything to you later," Caspian said, his voice low but resolute. "Eat and rest, Marcus. Please."

Before Marcus could press further, Caspian turned and swam away, his powerful tail cutting through the water with ease.

A soft sigh left Marcus's lips as he watched him retreat toward the throne. The weight of unspoken words hung between them, and for the first time, Marcus felt the daunting chasm of who Caspian truly was—and who he, Marcus, might have to become.

______

A soft burp escaped Marcus as he set his empty cup back on the tray. Plates were scattered across the small table, the remnants of his meal sitting comfortably in his stomach. He had considered having dinner with Morgan and Atlantis, but the unspoken tension between the two was palpable, and Marcus didn't feel like being an unwilling spectator to their brewing storm of emotions.

He sighed, glancing around the room. It was more spacious than he'd expected, with a large cushion draped in sheer, flowing curtains taking up the center. The dark walls were illuminated by blue and red lights, blending into an ethereal purple hue that bathed the room.

A vanity table was fixed to one wall, the black-framed mirror catching his reflection. For a moment, he gazed at himself, his silver eyes flickering with the soft light. But something else caught his attention—a shadow lingering just behind him.

"Beautiful, isn't it?" came a soft, lilting voice.

Marcus turned sharply, his heart skipping a beat as his eyes met Lilith's glowing violet gaze. She drifted in the water, her sharp nails trailing lazily along the black stone walls as if they belonged to her.

"Oh. Hello, Lilith," he said, his voice hesitant but polite.

Her lips curved into a smile, though it didn't quite reach her eyes. She swam closer, her movements fluid and predatory. "How do you like it here?" she asked, her tone sweet, almost too sweet.

Marcus chuckled nervously, rubbing the back of his neck. "It's... very pretty," he admitted, carefully choosing his words. A quiet alarm sounded in the back of his mind, warning him not to let anything slip. He didn't know if Lilith had guessed the truth about him—that he was human—but something told him it was better to keep it hidden.

The false warmth in her demeanor vanished in an instant. Her smile faded, her eyes narrowing with barely concealed fury. "Caspian is mine," she said abruptly, her voice sharp and cold. The words sliced through the air like a blade. "I don't care if you're mated or not."

Marcus stiffened, gripping the edge of the vanity table as she swam closer. Her nails gleamed like polished daggers, stopping mere inches from his eye. He held his breath, refusing to flinch.

"Besides," she continued, her tone dripping with venom, "I have the parts to produce an heir. Unlike you." Her sneer deepened as she leaned in, her voice dropping to a hiss. "To make it crystal clear—I can give him children, and you can't. Do you really think the council will allow a king to be with someone who can't continue his bloodline?"

The words hit Marcus like a punch to the chest. His heart clenched painfully, and his mind raced as the truth of her statement sank in. Caspian wasn't just his mate; he was a king. A royal who carried the weight of an entire kingdom on his shoulders. And with that came expectations—ones Marcus could never fulfill.

Lilith's lips curled into a cruel smile as she watched the realization dawn on him. "Stay away from him, or you'll regret it," she snarled, her voice low and dangerous. Without waiting for a response, she flicked her tail and disappeared, leaving Marcus alone in the now-stifling room.

For a long moment, he didn't move, his fingers trembling as they brushed against the edge of his eye—the one she had come so close to gouging out. The faint sting of her presence lingered, like an invisible wound beneath his skin.

His chest tightened as Lilith's words echoed in his mind, each one a dagger twisting deeper into his heart.

I can give him children, and you can't.

Tears burned in his eyes, threatening to spill over as he clenched his jaw. He stared at his reflection in the mirror, the silver of his gaze now clouded with sorrow and despair.

"Caspian," he whispered, his voice cracking under the weight of his emotions. The name was both a plea and a lament, a fragile tether holding him together even as he felt himself breaking.

He curled his hands into fists, his nails biting into his palms as the tears finally fell, silent and unbidden. Lilith's words had planted a seed of doubt, and no matter how much he wanted to push them away, they remained—a cruel reminder of everything he feared he could never give the man he loved.