From Master Assassin to a Random Extra: OP in a Dating Sim
Chapter 69: Marcus and Cynthia (3)

Chapter 69: Marcus and Cynthia (3)

They both moved, slow and cautious, the water around their boots rippling in expanding rings. Each step disturbed the surface tension just slightly—but the scent in the air was growing stronger now. That coppery, iron tang. Blood. And it was fresh.

"We’re getting nearer," Marcus murmured, voice low, his eyes flicking ahead with focused precision. "That much is clear."

They advanced carefully through the subterranean lake, the only sounds being the quiet slosh of water and the distant, unearthly drip of moisture from the crystal-studded ceiling. Every ripple they made could be a warning bell to whatever monstrosity lurked ahead.

Cynthia trailed a few meters behind, as usual. Her role was clear—rear guard and retreat anchor. If things went wrong, she’d be the fallback point. The lifeline.

"What do we do if we can’t beat it?" she asked quietly, tension edging her voice. Her eyes scanned the murky depths and the glittering cave around them. "We’re surrounded by water. Not exactly ideal terrain."

Marcus chuckled under his breath, glancing back briefly with a glint in his eye. "You have any earth runes?"

Cynthia nodded slowly. "Yeah. Enough to move... maybe a boulder or two. Why?"

"Then we should be fine." He gave her a confident smirk, offering no explanation, only trust in his own plan.

Cynthia exhaled through her nose, uncertain. Her grip tightened on her wand. She didn’t understand how earth magic would help in the middle of a flooded cave, but... Marcus was Marcus. The strongest between them. If he was calm, she had to believe he had a way out.

"Stop," Marcus whispered suddenly.

He raised a finger to his lips, eyes narrowing, his entire posture going still. Cynthia followed his gaze—and froze.

Across the vast underground lake, partly submerged in the glimmering water, a Crystalline Wyrm lay coiled like a sleeping dragon from legend. Its scales shimmered with a radiant sheen, covered in natural crystals that mimicked the ones jutting from the cave walls—prismarine blue and razor-edged. Its eyes, half-lidded but alert, reflected the light like cut sapphires.

It was massive—easily the size of a mansion, and any normal person beside it would look like a bug on the floor of a ballroom. Beside the beast, a grotesque pile of gutted fish and mangled prey lay stacked, blood staining the water a muted red.

So that’s where the scent was coming from.

"Hey... Cynthia," Marcus whispered, this time with a nervous edge in his voice. "Can an S-Class student beat that thing?"

He chuckled faintly after asking—but there was no humor in it. His instincts screamed. Every part of him told him to turn and bolt.

This wasn’t like the Wolf Lord. This thing wasn’t just dangerous. It was a nightmare incarnate.

Cynthia gulped, shaking her head ever so slightly. "Unless you’re a professor? Not a chance..."

She bit her lip, remembering the harsh truth. S-Class students weren’t full S-Class mages. Not yet. The ranking only meant they had the potential to get there. Even a highly talented student could be crushed by a low-tier professional mage if they lacked battle-hardened theory and practical spell layering.

Marcus exhaled through his nose, chuckling again—this time less amused, more resigned. "Let’s move back. Quietly. Another route’s gotta exist."

Cynthia nodded immediately, her steps aligning with his. They backed away slowly, both conscious of every ripple they made in the water.

"No need to tell me twice," she murmured.

But fate had other plans.

Above them, a deep, rumbling tremor echoed—another shockwave from the battles still raging far above in the upper levels. The vibration dislodged one of the large crystals embedded in the cave ceiling.

A spike the size of a grown man fell like a divine spear, crashing into the lake not far from them.

SPLASH!

The explosion of water roared through the cave, sending ripples in every direction. It hit the wyrm.

And then came the echo—thunderous, resonating across the entire cavern system. The worst part? The spike had landed frighteningly close to where Marcus and Cynthia stood.

The Crystalline Wyrm stirred.

It raised its head slowly, those gem-like eyes narrowing, pupils shrinking into slits. Then it uncoiled with terrifying grace, its massive body undulating as it turned its head in their direction.

Predator.

Prey.

A simple equation.

Marcus and Cynthia locked eyes. Their bodies were frozen in fear, pulses pounding in their ears.

"...Run?" Cynthia whispered.

Marcus nodded sharply. "Run!"

He slapped his palms together, runes on his feet igniting instantly. The water beneath his feet hissed, bubbling violently as flame sigils activated, superheating the liquid into pressurized jets.

BOOM. A sonic burst erupted under him as he rocketed forward, the water beneath turned to vapor trails. He reached Cynthia in a blur and scooped her up again, arms hooking under her legs and shoulders.

Another princess carry. Another escape.

"How lucky of us!" Marcus shouted with manic laughter as he flew across the cave’s surface, leaving a smoking trail in their wake.

Behind them, the wyrm surged, its crystalline mass carving through the water like a serpent of destruction. It crashed against the cave walls, breaking crystal pillars and sending down another cascade of shards with each turn.

A high-speed chase had begun.

As they fled, Cynthia used her free hand to deflect incoming shards, clearing a path so Marcus could focus entirely on maintaining their speed without worrying about stray crystal pillars.

"Earth magic!" Cynthia shouted over the roar. "Tell me what to do!"

Marcus grinned without turning. "Open up a hole—in the ceiling ahead!"

Cynthia wasted no time. She twisted her wand in a sharp arc, runes circling her fingers in rapid succession. A rumble answered her command as the stone overhead cracked and shifted—an opening forming just in front of them.

Marcus twisted mid-air, briefly glancing back at the oncoming beast. "I’d love to fight you, but you’re way too damn huge!"

He clenched his teeth and switched sigils, activating a combustion rune beneath them. A focused blast erupted under his feet—

KRA-KOOM!

The explosion launched them upward, a jet-assisted leap that propelled them like cannon fire toward the hole.

Below them, a thick fog bloomed, generated by the sudden vaporization of water from his previous jet trail. The wyrm hissed, its vision obscured as it lost track of its fleeing prey.

"Once we’re through—seal it!" Marcus barked.

"Got it!" Cynthia replied, wand at the ready.

The moment they passed through the opening, she flicked her wrist, sealing the stone behind them. A dense slab of earth and crystal formed a tight cocoon, cutting them off from the chaos below.

Darkness swallowed them.

"I can’t see anything..." Cynthia whispered, voice echoing in the hollow chamber.

Marcus finally let her down, setting her gently on her feet. With a casual flick, a small flame danced on his fingertip—just enough to illuminate their cramped hideaway.

"We’re safe. For now," he said, breathless but steady. "The fog I made should buy us time. It won’t know where we vanished to."

Cynthia’s knees buckled, and she let out a short laugh—part relief, part disbelief—as she sank to the cold stone floor. "We survived..."

Marcus grinned and slid down beside her, back hitting the cave wall with a dull thud. "Yeah, all thanks to my flawless plan."

Cynthia rolled her eyes, a playful smirk tugging at her lips. "I’d call that a plan, but ’flawless’? Not quite."

Marcus shrugged with a cocky grin. "Details."

Cynthia smiled faintly, shaking her head. "Next time, try not to look so damn thrilled about it."

"No promises," Marcus said, eyes twinkling.

She reached out, brushing her damp hair back and then lightly touching his arm. "Seriously, though. Thanks."

Marcus met her gaze, his smile softening. "Anytime."

Cynthia [Affection: Fond +22] +7

Current Emotion: Thankful

Marcus blinked as the system chime echoed faintly in his ear.

"...Huh," he muttered, smirking faintly. "Didn’t expect that."