The lights hummed to life with the rising sun, flooding the lab in pale white.
Aaron stirred first, blinking slowly as the sudden brightness burned at his sensitive eyes. He winced, shifting his aching body against the cold floor. His limbs felt like they weighed twice as much, muscles sore and trembling from the constant shifting and pulling within him.
Then he saw movement.
Through the glass, just outside the monitoring chamber, David sat up with a jolt—blinking as the fluorescent light woke him from shallow, restless sleep. The second their eyes met, time stopped.
David was out of his chair in a heartbeat, rushing to the glass, hands pressed flat against it. Aaron mirrored him, pulling himself up just enough to raise one paw and meet his father's through the divide. Both of them looked close to tears.
David's voice crackled through the comms system, raw and shaking.
"Aaron..."
He swallowed hard. "Can you hear me?"
Aaron nodded weakly.
"Can you speak?"
Aaron opened his mouth, but nothing came. His throat moved—he tried, but no sound came out. He winced, shaking his head. Still no voice.
David seemed to deflate slightly, but forced a gentle smile. "That's okay... it's alright. Nod for yes, shake your head for no. Can we try that?"
Another slow, careful nod.
"Okay..." David exhaled. "God, I'm so glad you're still... you."
The connection between them—unspoken but deeply felt—carried more than words ever could. But even in that moment of fragile comfort, the lab's monitoring system broke the silence with a sharp, persistent beep-beep-beep.
David spun around and checked the screen. His eyes scanned the lines of data until a new message blinked onto the display:
"UNIDENTIFIED GROWTH IMMINENT."
His stomach twisted.
Returning to the comm, David tried to keep calm, but Aaron could hear the tremble in his voice. "Aaron, listen to me. Something's about to happen—your body's still... changing. I—I don't know what it is, but the system's picking up something forming. Just hold on. Whatever happens, just... try to bear it, okay?"
Aaron gave the slightest nod, but barely had time to process the warning before it hit him.
The pain shot through his lower spine like a bolt of lightning—searing, raw, and unrelenting. He screamed, body arching as if something were being ripped out of him. The monitors spiked, blaring with alarms as his heart rate surged.
David's hands slammed against the glass.
"AARON!"
Inside the chamber, Aaron collapsed onto the floor, spasming violently. He clawed at the concrete, leaving jagged scrapes as his back writhed under an invisible pressure. His breath came in rapid, shallow gasps. Every nerve in his body screamed as the base of his spine pushed outward—stretching and warping.
Something grew.
David could only watch in horror as Aaron's spine visibly extended under his skin, pushing against the base of his back and finally erupting out into a thick, fleshy appendage.
A tail.
Aaron wailed—his voice distorted and trembling as if it belonged to someone else entirely. The new limb lengthened by the second, layer by agonizing layer of muscle and bone forming. Two feet. Four. Six.
It finally stopped just over six feet long, the thick tail curling slightly behind him. Grey fur quickly covered its surface, and from its tapered end, translucent blue membranes unfurled—like a shark's tail fin, glowing faintly in the sterile light. A smaller pair of fins formed further up the tail, one on each side.
Aaron's body shuddered violently as the pain settled for only a moment before returning—this time to his head.
His ears twitched, then began to move. They crawled upward along the sides of his skull, reshaping, tapering to points, becoming sharp and alert. He screamed again, gripping his head with both paws as if trying to hold it together, trying to stop it from splitting apart. The movement sent shivers through David's spine.
Then, something else changed.
Where his original ears once were, two soft, glowing fins pushed free from the sides of his head—vibrant blue, thin and luminous like the ones on his tail. They glowed brighter with every ragged breath.
David stared, jaw slack, eyes wide in disbelief.
And then... Aaron's jaw began to extend.
He tried to hold it back, pressing his paws to his face, but the pressure was too much. His teeth ground together as his mouth pushed outward—his entire lower face restructuring into a short, feline-like muzzle. His teeth lengthened, sharp and predatory. A soft growl escaped him—pained, pitiful, almost instinctive.
David couldn't take it anymore.
"No—no, please," he whispered to himself, fists shaking against the glass. "You've been through enough..."
Aaron whimpered again, his glowing eyes flickering as he slumped forward.
The pain had pushed him to the edge—and this time, it won.
His body went limp against the chamber floor, tail curled protectively around himself, still faintly twitching. His breaths were shallow but steady.
The monitors beeped slower now, stabilizing as the transformation paused once more, seeming to finally have stopped.
David dropped to his knees outside the glass, trembling. He felt like something in him had broken. Not just as a scientist. But as a father. Watching your child suffer and being completely unable to help—it was the most helpless, agonizing feeling in the world. Watching your child become a completely different creature—that was a whole other thing...
He pressed his forehead against the barrier.
"I'm sorry, Aaron," he whispered, barely audible. "I'm so, so sorry."