Wow… this was an amazing book. It was less of a horror than I expected and more of a beautiful, dark coming of age story. There were so many things that I loved: obsession, sapphic romance, mythology and quiet horror. I loved the way it was written and the letters from Cathy added another layer to the book. It was reflective and melancholy in tone which I adored. All the talk of swimming was really interesting and I enjoyed learning about the sport. The toxicity of the competitive world was hard to read about - I felt for Ren and hated Jim. I enjoy when characters are passionate about something so seeing Ren’s love of swimming and mermaids develop into an obsession was something I loved. Ren was a good character to follow and I loved seeing her story. The body horror was fantastic and made my skin crawl a little!! Yes there could have been more but I actually think there was the perfect amount. The final chapters were shocking and disturbing yet almost beautiful. I think there were a lot of important messages in this book - about race, love, growing up and being who you want to be.