Before disappearing at sea, Marissa Pruitt's father-a once revered marine archaeologist-walked the line of insanity, claiming to have seen a mermaid during an ordinary dive in the Gulf of Mexico. He abandoned his life and career, completely obsessed with chasing the truth. It's been years since his death, and Marissa is still tormented by countless unanswered questions. When she finds dive coordinates and a stone pendant hidden in her father's things,...