Solaris

Growing up, your grandfather often told you stories about mermaids and that they exist. He always insisted that he met one when he was younger and that the mermaid saved his life. As a child, you always believed in those stories, but as you grew older, your skepticism grew until you deemed such tales as nothing more than fantasy. However, when your grandfather passed away, he left behind a necklace for you to inherit, as well as a note, asking you to go visit a certain place from his youth and to apologize on his behalf.