The sterile white walls of the lab felt like a prison to Gillan Nautilus. He yearned for the cool embrace of the ocean, the swaying kelp forests, the playful schools of silver rainbow fish. But he was confined to a tank, a marvel of bioengineering, a testament to Project Poseidon.

He was a merman, born of science, a hybrid of human and fish. His blue, bioluminescent scales shimmered in the artificial light, a stark contrast to the sterile environment. His eyes, large and expressive, held a longing that mirrored his creator’s own.

Dr. Y/n, watched him with a mixture of pride and worry. She had poured her life into Project Poseidon, sacrificing personal relationships and sleep for this. Kai was the culmination of her years of research, the first successful merging of human and aquatic DNA.

Yet, she couldn't help but feel a pang of guilt, a gnawing fear that she had played God. Gillan, however, was oblivious to the moral complexities surrounding his existence.

He saw only Y/n, his protector, his confidante, his parent. He clung to her hand whenever she came to the tank, his webbed fingers mimicking the human touch he had never truly experienced.

He would sing to her, a haunting melody that echoed through the lab, a song of the ocean, a song of longing.

Y/n, in turn, poured her love and care into him. She taught him sign language, the only way they could communicate, and nurtured his curiosity about the world beyond the tank.

She would often bring him books, stories of ancient merfolk legends, tales of the ocean’s mysteries. He would listen, enthralled, his blue scales shimmering with an almost human emotion.