Chapter Text
Days have passed since the enchanting night in Stone’s underwater cave.
Robotnik sat alone in his lab, surrounded by glowing blue projections. Holographic panels hovered in the air, displaying schematics for a new lab—no, a new home. Sleek structures shaped like sea-polished stones floated mid-air in miniature, slowly rotating. His fingers danced through the controls, adjusting materials, reshaping sizes, refining the smallest of details.
The location was set: a private stretch of shoreline he had quietly acquired. It was close to the water and far from the prying eyes of any nosey neighbours and government meddlers. Remote, but not isolating. Stone would like that.
Around his neck, on a simple black cord, hung the red rock Stone had gifted him. It no longer glowed—being so far from the cave—but Robotnik wore it as if it were his most essential tool. He’d absently touched it many times tonight without realizing.
He spun the 3D hologram again and frowned. The exterior was too cold—too Robotnik. It also needed to reflect being Stone’s home too. “Colour,” he muttered, adjusting the display. The lab glowed in golden bronze, then grey, then deep red.
Then he paused.
“Baby blue,” he murmured to himself. “Stone said his father’s house had baby blue window frames…” With a few more flicks, the window accents turned soft blue. Robotnik stared at it for a moment, unexpectedly still.
Satisfied, he leaned back, admiring the design. Tonight, he would show Stone the plans and then ask him to move with him. Stay with him at their new home. A place where he and Stone could live together—no more hiding in caves or stolen moments. Just the two of them. Away from the worlds that rejected them and to make their own world. The thought filled him with a mix of excitement and uncharacteristic nervousness.
Just as he was running a final check on the dimensions, a voice disrupted his thoughts, sharp and grating. “Well, isn’t this cozy,” drawled Starline, stepping into the lab like he owned the place. “Very…Doctor Robotniky.”
Robotnik froze, then quickly flicked his wrist, and the holographic display vanished. He sprung up from his seat to threaten the intruder. But when he say who it was, his flames burned hotter. “Starline! How the hell did you get in here?”
Starline’s smirk widened as he strolled further in, hands clasped behind his back. “Oh, Doctor, you underestimate me. I’ve always had a talent for slipping into places. Like a octopoda.”
Robotnik’s eyes darted to the floor, catching movement near Starline’s feet. A small, white-shelled crab scuttled toward him. At first it looked like a regular crab—until it got closer. Transparent shell. Exposed wires. Its beady lens-like eyes glowed faintly red. It climbed Starline’s leg and into his lab coat pocket.
“A robotic crab?” Robotnik thought, his fists clenching. “He used that dammed thing to bypass the security systems. Damn it, I knew I should’ve replaced that ancient wiring myself! Screw Walters!” He swore under his breath, cursing both his oversight and the facility manager who had denied his request to overhaul the lab’s security.
Starline pulled the robotic crab from his pocket, letting it crawl over his gloved hand like a pet. “Ingenious little things, aren’t they? I built him myself, designed after ocypodinae. But I must admit, your lab’s defences gave it quite the challenge, but, alas, it wasn’t enough.” He tilted his head, his smirk turning sharp and his glasses reflecting off the lights. “I wonder what you were so eager to hide just now. Perhaps a personal project? A new weapon, maybe?”
“Ooooh, get to the point,” Robotnik snapped, stepping forward, his boots echoing with finality against the cold lab floor. His voice was ice, but his blood boiled beneath his skin. “I only have enough patience to activate one of my badniks to shoot you down, so get to it.”
Starline only smiled, the motion slow and deliberate. “Oh, I have a point, Doctor,” he purred, slipping the crab back into his pocket like it was a prize. “But all in good time. I thought we might have a little chit-chat first. Catch up, as it were. After all, it’s been so long since—”
Robotnik raised a hand, typing a command into the interface on his glove without looking at it. His glare remained locked on Starline as one of the badniks on the back wall sparked to life—its eyes glowing red, floating up and locked onto the intruder in the lab. The faint whirrrrr of gears filled the room, the barrel on the badniks gun arm rotating slowly as it zeroed in.
Starline chuckled, raising his hands slightly in mock surrender. “Alright, alright, I’ll skip the pleasantries.” He took one step to the side, letting the red eyed killer orb follow him. “Still not into small talk, I see.”
Robotnik said nothing, but his glare sharpened. Starline was one wrong word away from giving the order to fire.
Starline, still unfazed, adjusted the cuff of his sleeve with maddening calmness. “Anyway, I am here to inform you that I’ve managed to capture that merman boyfriend of yours.”
Robotnik’s entire body stiffened. The air thickened. The whir of the Badnik grew louder in the silence.
“You’re delusional,” Robotnik said, his voice even but icy. “I have no idea what you’re babbling about.”
Starline’s smile stretched, teeth bared all shark-like. “You heard me.” He pulled a black phone from his inner coat pocket and tapped the screen. “I’ve been tracking him for a while. That precious little beach of yours? Not as secret as you thought.” He turned the phone to Robotnik. Live feed played on the screen: a large cylindrical tank bathed in artificial light. Water filtered through vents and pulsed with a soft current. Inside, a familiar figure swam, disoriented—frightened.
Robotnik stepped forward before he could stop himself.
Stone.
Pale under the false lighting. His tail flicked slowly, sluggish with fatigue Stone swam in nervous circles, his movements unsteady, his expression a mix of fear and desperation. And around his neck—Robotnik’s heart dropped. His collar. The one he had built for Starline for his ‘aquatic behavioural control study’. It latched firmly around Stone’s throat.
And for the first time in years, Robotnik felt guilt coil in his chest like a snake. The collar wasn’t meant for this. Never having thought something he made would be used against someone he cared about.
Starline, savouring the silence, leaned closer, his voice dripping with mockery. “I must say, Doctor, it’s fascinating to see you so...human. I watched you last week emerge from the water with that creature, and then seeing you kiss it—it was almost touching.” He chuckled, pulling up another video clip on his phone. The footage was from last week, after Robotnik was shown Stone’s cave. It showed him emerging out of the ocean, dripping wet, with Stone lingering behind him in the waters. Then came the kiss—tender, unguarded, undeniable.
Robotnik’s jaw tightened.
“Still going to deny it?” Starline pressed.
Robotnik said nothing, his mind frantically working through possible escape routes.
“Well, let’s try a different approach,” Starline said, pulling a small remote from his coat pocket. His thumb hovered over a button. “Recognize this, Doctor?” Withput waiting for Robotnik’s response Starline pressed the button, and on the live feed, Stone writhed in agony, his body convulsing as the collar emitted a painful electrical shock.
Robotnik’s hands balled into fists. “Stop it!”
“Say the magic words,” Starline taunted, holding the button down firmly.
“STOP IT NOW! P-PLEASE!” Robotnik’s voice thundered, louder than he intended, his mask of indifference cracking. Starline lifted his thumb, and the shocking ceased. Stone floated weakly in the tank, his breathing ragged.
“That’s better,” Starline said, tucking the remote and phone back into his coat pocket. “You’re now predictable, Doctor. As cold and calculating as you pretend to be, it seems you have a weakness after all.” He began to pace slowly around Robotnik, like a predator circling wounded prey—his boots clicking against the metal floor with precise rhythm. “I’ve been watching for a while now,” Starline spoke, his voice like oil. “You were sloppy. Emotional. And I must admit I never thought the cold-hearted Doctor Robotnik would find someone—or something—that could thaw that little icicle of a heart. But here you are. Playing house with a marvellous specimen sea creature.”
“It’s not like that,” Robotnik hissed through gritted teeth.
Starline raised a finger. “Oh, but it is. You’re compromised. And it’s adorable.” He turned, strolling slowly through the lab. “But I’m not here for your love story. I’m here for his biology.”
Robotnik froze, but his glare remained murderous, but Starline continued unperturbed.
“I suppose I should tell you why I’ve gone through all this trouble,” Starline said, his tone taking on a sinister excitement. “The merfolk, like your precious merman, have an incredible ability to heal their wounds rapidly, almost instantaneously. Imagine the applications in our world: soldiers recovering on the battlefield, entire armies back to fighting strength in minutes. Governments would pay billions for this kind of technology.”
“You’re a madman Starline,” Robotnik spat. “A monster.”
Starline grinned, unbothered. “Says the man who builds armies of mechanical abominations to terrorize the world. Let’s not throw stones, Doctor.”
Robotnik’s fingers moved sharply over the controls on his glove. The awaiting badnik activated behind Starline, its red targeting sensors locking onto his skull and its gun emerging ready to fire.
But Starline, ever unfazed, simply raised a gloved finger with a slow, patronizing wag. “Ah, ah, ah. I wouldn’t do that, Doctor.”
Robotnik narrowed his eyes, but his fingers hovered, unmoving, just above the final command.
“You see,” Starline said, voice taking on that maddeningly smug edge, “I also had the liberty of upgrading your precious collar. A little bonus feature, if you will. Fail-safe insurance.” He tapped his temple lightly with one finger, eyes locked onto Robotnik’s with unsettling calm.
“The collar,” he continued smoothly, “is now rigged to detonate in the event of my untimely demise. Instant neural overload. Quick. Painless—relatively speaking.”
Robotnik’s lip curled. “You’re bluffing.” His finger twitched over the command input.
Starline’s expression didn’t waver. If anything, it grew more amused, more pitiful.
“Oh, please. I expected more from you, Doctor. But by all means—take the shot. He took a small, arrogant step forward, lifting his chin, arms held out in mock invitation. Tempting. “You always did want to see me drop dead, didn’t you? Go on. Kill me now… and then go find your lover floating dead in the tank. As soon as I hit the floor, it’ll be enough time for the collar to pulse straight through his nervous system. Frying him from the inside out.”
Robotnik’s jaw clenched. His fingers hovered over the final command, trembling just slightly. His mind raced. He wanted to call the bluff. Starline had to be bluffing.
But this was Starline. He’s broke into his lab, bypassed his security, used those cursed crabs—And he’s managed gotten to Stone.
Stone.
Robotnik’s breath caught. The thought of Stone screaming, alone and in pain, because of him—No.
He disengaged the badnik, lowering his hand in defeat. Robotnik’s voice was low and guttural, barely more than a growl. “What do you want?”
“It’s quite simple, Doctor,” Starline purred, tilting his head. His boots tapped against the floor as he stepped forward, smug and predatory. “You work for me. Build machines. Refine tracking systems, capture methods, biological containment units, blah blah blah. Just some tools that will help me study and find more of your boyfriend’s kind.” Robotnik’s fists clenched, but Starline went on, voice dripping with false sympathy.
“In return, I’ll let your precious little merman live. Refuse and, well—” He shrugged with maddening casualness. “I don’t need him alive to conduct my studies. You get the picture?”
Robotnik’s teeth ground together. His every instinct screamed no, screamed fight, screamed kill him. But he couldn’t. Not when Stone was the one who would pay the price. He saw flashes of Stone’s eyes—wide and afraid in that enclosed tank. The collar around his neck. The betrayal that would be written across his face once he knew what Robotnik had agreed to. And yet—
“Fine,” Robotnik spat through clenched teeth. “I’ll do it.”
Starline beamed, almost delighted—as if Robotnik’s suffering were the punchline of a long-running joke only he could hear.
He stepped in close, uncomfortably close, and lifted a gloved hand to pat Robotnik’s cheek. “I knew you’d see reason,” he cooed mockingly, the gesture somewhere between condescending affection and calculated humiliation.
Robotnik didn’t flinch. He stood still as stone, his eyes deadened, jaw clenched so tightly it felt like his bones might crack.
Starline turned away with a swish of his coat and began to make his way out. At the threshold, he paused. “I’ll be in touch, Doctor. We’ll have so much fun.” And then he was gone.
The moment the door hissed shut, Robotnik dropped like a marionette with its strings cut. He fell to his knees in the middle of the lab—alone. The cold floor met him without mercy. His hands reached for the red rock that still hung from his neck. He pressed it to his chest, curled around it as if it could protect him from the truth. His breath hitched. Then again. Until it came out in a choked sob.
“How can I face him…” he whispered, voice raw and cracking, “…when I’m the reason for his pain?”
His shoulders shook as the silence in the lab thickened, filled only by the sound of grief. He finally had everything he never thought he’d want—warmth, trust, love—and now a monster has control over it.
For the first time in his life, Doctor Ivo Robotnik wasn’t angry at the world.
He was angry at himself.
The tank was too small. It was no endless water.
No open currents to ride. No distant coral spires or drifting kelp forests. Just thick, glass boundaries that distorted his reflection and turned the world into a prison of stale light and cold silence.
Stone drifted in the centre of it, arms folded tightly across his chest, his long tail coiled beneath him like an anchor. He hated the stillness. The sterile hum of machinery. The way the water never shifted unless he moved. The walls were thick. Curved. Designed for observation as much as confinement. It wasn’t water—it was containment.
Earlier, he tested the boundaries—swimming to the farthest end, prodding at the seams where glass met metal. But a painful shock hit his neck when he tried to claw at the seal, sending pain lancing throughout his body. He hadn’t tried again since.
Now, he simply floated, slow and listless, his tail occasionally stirring the water like an afterthought. His eyes were half-lidded. Dull.
The lab was empty now, dimmed to standby mode, the overhead lights in conservation cycles. But cameras glowed like mechanical eyes embedded in the corners—always watching. He’d counted three.
He turned slowly, a dull ache settling into his muscles from inactivity. In the faint curve of the glass, Stone could see his own reflection. His skin had paled under artificial lights. There were bruises on his neck, faint but unmistakable, darkening around the collar that clung like a shackle. His hair drifted around him, unkempt and tangled, his eyes sunken from exhaustion.
He didn’t know how long he’d been in captivity. With no sun to rise and no moon to follow, the hours became meaningless. The water was filtered and tasteless—too clean, too still. No sand or salt carried on tides or whale songs echoing in the deep. Just the constant hum of machines and the muffled click of robotic arms adjusting dials he didn’t understand.
The only light came from sterile bulbs above, occasionally shifting hues, but never enough to distinguish night from day. All he knew was this: the tank never changed. The ache in his body never faded. And the loneliness never stopped.
He remembered fragments of that night—his last night in the sea.
The sun had been high, and the water warm against his skin. He had been resting in his cave, dreaming of warm coffee and of the human he had let into his world. And heart.
And then—chaos. A scream half-choked in saltwater. Harpoons. Nets that sparked when they touched him, tightening even as he twisted to flee. The scent of metal and fuel in the water. Dozens of hands dragging him from his sanctuary.
That was the last he remembered before waking up in the tank. Bruised. Scared. Alone.
Stone raised his wrist slowly, the motion stiff from disuse. His fingers trembled as they brushed over the soulmark. His chest tightened.
Does he know I’m gone? The thought crept in like a cold current. Does he feel it? Did the mark burn to alert him?
His thumb traced the familiar ridges of the mark. The memory of Robotnik’s hand over it. The way it glowed when they touched—like something ancient and magical awakening between them. The first time Stone truly believed that soulmates could exist.
Will he come for me? His gaze lifted to the curve of the tank glass, to the cameras that stared back, unblinking. Can he even find me? Or had they made sure he couldn’t?
A flicker of doubt pierced his heart like a harpoon.
He squeezed his eyes shut, clutching his wrist close to his chest, pressing the mark close to his heart.
Then came the hiss of the lab doors opening.
Stone flinched and pushed back slightly in the tank, alert and tense. The figure who entered was the same man who had given the order that night—tall, green glasses, white-haired and pristine, as if untouched by the ugliness of his work. Starline. The commander. The one who’d smiled as Stone had screamed whilst being carried away on the beach.
Stone glared at him, ready to bare his teeth—until someone stepped through the door behind him.
Stone’s heart lurched.
It was him.
Robotnik.
Stone’s body froze, heart racing loudly in his ears. He was here. He was alive. Maybe this was it. The rescue. The end of the nightmare.
The white-haired man said something to Robotnik, gesturing to a tablet in hand. But Robotnik seem to pay attention to the man. Neither did he with Stone. He hadn’t even look at him at first.
But then, slowly, Robotnik raised his head and their eyes met through the glass.
Stone swam forward until he could press both palms to the transparent wall. His fingers splayed against it. Waiting. Hoping. A silent plea. Please. Come to me.
He watched Robotnik’s eyes.
Waited for a spark. A smile or a wink. A twitch of his fingers.
But he did nothing. Not a move. Not a word. Not even a glance of sorrow.
Stone hovered there, motionless in the tank, his hand still pressed against the glass. The faint hope that had flared in his chest.
And then, with a hollow look in his eyes, Robotnik turned. No parting glance. No comfort. No gesture of reassurance. Just a cold pivot and footsteps that echoed as he followed the other man to another room. The heavy doors hissing shut behind them.
Stone didn’t move.
He couldn’t.
His hand dropped from the glass, his limbs floating limp in the water. A scream had clawed its way to the base of his throat—but it stayed there, swallowed by the crushing weight in his chest.
He wanted to believe there was a reason. That Robotnik had been forced, coerced—anything but this. Anything but the man he loved choosing to walk away.
He saw me. He looked at me.
And he just…left me.
Something inside Stone cracked, jagged and irreparable. Loneliness he had known before.
But it was different now. This was betrayal.
The mark on his wrist pulsed faintly against his skin, but there was no warmth to it now. No glow. Only a dull reminder of something that had felt like destiny… and now felt like a curse.
He drifted backward, away from the glass, curling himself into a slow spiral near the bottom of the tank. His back brushed the cold, false coral, as if aesthetics could mimic the wild and dangerous beauty of the sea. Burying his face into his folded arms, clutching the mark on his wrist with trembling fingers.
He wanted to scream. To thrash. To cry.
To cry for his father, gone long ago. For his mother, lost in the tides.
And now… for Robotnik. The one who had kissed him like he was more. Who made the world seem so much bigger. Who had looked at him like he was the only one left in the world.
But now he felt foolish. Used.
Liar.
Stone wrapped his arms around himself, eyes half-lidded and distant.
He wanted to cry. But he couldn’t. He never had a tear make it to his cheek without being absorbed by the endless ocean.
But if he could’ve—he would have sobbed until the tank turned to salt.