In order to fulfill his lifelong wish and graduation project of researching merfolks, Desharow, a student of Biology Department of Russian Maritime Academy, went on a long distance voyage with his mentor, Rhine, and caught a special species of male Merfolk in Iceland. Little did he know that this mysterious dark and evil creature had long since regarded him as his "prey" (cough cough spouse) and had been invading his body, leading to an unexpected trigger to a thrilling conflict.

In the end, can the merman's instinctive desire prevail or not, and whether the research of Desharow can proceed smoothly under the obstruction of his mentor with the same misguided idea? What is the real purpose of the investigation that seemed to be hidden in the presence of military forces when a terrifying conspiracy dating back to World War II began to emerge….?

With the development of the research and the frequent occurrence of various dangerous incidents at sea, emotional struggle, and instinctive love, Desharow soon discover some incredible connection toward the evil black-scaled merman and how his body had undergone some unique alteration.