Hidden [Mermaid novel]

A story about some hidden secrets of the deep. Follow the story of the marine biologist John Haulton with his teammate Fina to discover what is it that he accidentally discovered. However, his friend's occurrence took a strange turn from being someone who popped up from nowhere to joining him on his adventures being the only one to truly understand the secrets. Find out why John has been hooked onto an unknown marine creature for many years of his life, and what is it Fina is hiding?